World of Ham Radio 1997/WOHR97_AmSoft_(1997-02-01).iso/sat/sat_06/amsoft.iii

Text File | 1997-02-01 | 134KB | 2,623 lines

                        Element Manager Version 1.8
                Satellite Element File Maintenance Program
                              Operation Manual



                           COPYRIGHT (C) 1992 by
                               Rick von Glahn
                          All Rights are Reserved



                        Written using QuickBasic 4.5



           This document is Copyright (C) 1992 by Rick von Glahn
                            All rights reserved


                                  CONTENTS

      LICENSE
      WARRANTY
      INTRODUCTION
      REQUIREMENTS AND LIMITATIONS
      THE COMMAND LINE
      INSIDE THE PROGRAM
             THE MAIN MENU
                 SHOW STATISTICS
                 WRITE NEW FILE
                 AGE ANALYSIS
                 SELECTION CRITERIA
                 VERIFY CHECKSUMS
                 CORRECT CHECKSUMS
                 SHELL TO DOS
             FILE UTILITIES MENU
                  LOAD OR CHANGE FILENAMES
                  CREATE SELECT FILE
                  EDIT/VIEW ELEMENT FILE
                  CHECK FOR DUPLICATES
                  EDIT CONFIGURATION FILE
                  CONVERT AMSAT TO NASA 2-LINE
                  FILE VIEWER
      MISCELLANEOUS
      WISH LIST
      OTHER PROGRAMS LIKE ELEMENT MANAGER
      SOME SATELLITE TRACKING PROGRAMS FOR IBMS
      THANKS FOLKS
      SUPPORT AMSAT
      APPENDIX A - NASA 2-LINE FORMAT SPECIFICATIONS
      APPENDIX B - REPAIR PROCEDURES FOR BADLY FORMATTED 2-LINE FILES
      APPENDIX C - CREDITS
      APPENDIX D - REVISIONS TO ELEMENT MANAGER


                                  LICENSE


Element Manager is not a Public Domain program. As of this version (1.8)
it is provided free of charge.

Element Manager copyright (C) 1992 by Rick von Glahn.

Element Manager may NOT be modified in any respect, for any reason,
including but not limited to, de-compiling or disassembling the program.

You are free to distribute this version of Element Manager to others
subject to the above restrictions and also the following:

   A.   Element Manager must be transferred with all it's files intact.

   B.   No payments may be accepted for Element Manager. This does not
        apply charges incurred while accessing  computerized information or
        bulletin board systems.

Commercial distributors of "Public Domain" or "Shareware" software may
distribute Element Manager subject to the above conditions.


                                  WARRANTY


Element Manager is provided AS IS without any warranty, expressed or
implied.

I've attempted to check this program out during the debugging process but I
shall not be liable for any damages, whether direct, indirect, special, or
consequential arising from a failure of this program or accompanying files
to operate in a manner desired or anticipated by the user. I shall not be
liable for any damage to data or property which may by caused directly or
indirectly by use of this program.

In no event will I be liable to you for any damages, including any lost
profits, lost savings or other incidental or consequential damages arising
out of your use or inability to use the program, or for any claim by any
other party.

Because the program is free, no support is available. However, messages
concerning bugs, suggestions etc. may be addressed to RICHARD VONGLAHN on
the Celestial RCP/M BBS. I check the messages approximately once a week.


                                INTRODUCTION

Files Included with Element Manager Version 1.8

        ELEMAN.EXE - The program
        ELEMAN.CFG - Color Configuration file
        MONO.CFG  - Monochrome config file
        ELEMAN.DOC - This Document file
        SEMIVIS.SEL - Sample Satellite Select File (fairly visible sats)
        VERYVIS.SEL - Sample Satellite Select File (very visible sats)
        SATNAME.DAT - Catalog numbers and Satellite names data file
        READ.ME - A lame quickstart guide

Element Manager came into being while I was tinkering with a utility
program Steven Wood wrote for his excellent MR.ORBIT program. Steven's
program can extrapolate visual magnitudes of orbiting satellites if you add
some parameters to a Nasa 2-line prediction bulletin style element set.
However, this is a bit tedious and so, in order to make the program run in
versions prior to V.3, A utility program was included that would read in a
2 line file, and automatically add fudge figures for Mr. Orbit to use in
making predictions. These figures have to do with the satellite's visual
cross section (amount of reflecting surface).

Within Steven's utility was a line of code that started me to thinking.
This line of code read lines of a disk file sequentially into the
computer's memory. Well, that was the humble origins of this thing.

If you have downloaded this file then you probably have a strong interest
in satellite tracking. I've been addicted to this pursuit for several
years. I get a kick out of being able to determine where things are. And
once I got my Amateur Radio License (N0KKZ), I discovered that I NEEDED to
know where several of these birds were. One thing led to another an I
ended up being a regular supplier of orbital elements to the Denver,
Colorado area for the Amateur Radio community (an activity I no longer
engage in).

Each week I would download the latest elements from the Celestial BBS and
create subsets from this master file. I needed a short file easily
transmitted by packet radio that contained only those satellites of
interest to the Amateur radio operator. To fill this need I initially would
load the master element set into a word processor and block move element
sets one at a time to the top of the file. A tedious process at best. Sherm
Spahr WB0PCM saw that there was need for some type of program that would
create a new file with a selection of certain satellites the user was
interested in. I received a copy of this program in it's beta test days. It
was a real godsend. But there were certain things it would not do that I
was looking for. Rather than pester Sherm, I decided to wait and see what
he would come up with in the future. His program , "ELEMENT MASTER", is an
excellent utility and really does most of what anyone would want. But, time
passed, and I got impatient.


I get my elements from TS Kelso. Here's an advertisement:

-----------------------------------------------------------------------------
The most current orbital elements from the NASA Prediction Bulletins are
carried on the Celestial RCP/M, [phone], and are updated several
times weekly.  Documentation and software are also available on the
Celestial RCP/M. These orbital elements are provided to this system as a
service to the satellite user community.  The Celestial RCP/M may be
accessed 24 hours/day at 300, 1200, 2400, and 9600 baud using 8 data bits,
1 stop bit, no parity.                 - TS Kelso
                                         SYSOP, Celestial RCP/M
-----------------------------------------------------------------------------

That's the header TS likes us to attach to any files we distribute
procured from his board.

On the Celestial RCP/M BBS there is a file called TLE.ARC. It's always
called that so we addicts can use scripts in our COMM programs to
automatically download it. Inside the ARC file is TLE.TXT (surprise). That
file starts out like this:

----------------------------------------------------
- Current Two-Line Element Sets #907 -
Alouette 1
1 00424U 62B-A  1 91278.18950231  .00000260  00000-0  30107-3 0  4443
2 00424  80.4642 177.6948 0023282 128.3857 231.9385 13.67585388447616
etc.
----------------------------------------------------

Well there are two things wrong with this file. First, it isn't named
SATELE.278 (assuming that Alouette 1 is the most recent element set). And
secondly, it has an annoying (but valuable if you follow TS's numbering
scheme) header line.

Element Manager can automatically strip the header and copy the contents of
the TLE.TXT file into a new file with the name SATELE.278. You don't have
to do a thing baring writing a small batch file to get the job done. Here's
mine:

ELEMAN /Itle.txt /Osatele /P

note: you can just type this at the DOS prompt.

This line calls Element Manager, loads the input file TLE.TXT and tells the
program to automatically write a new file with the corrected filename and
adds the epoch day of the most recent element set as an EXTension to the
filename.

When Element Manager was born I was calling it Element Examiner and that's
about all it could do. However, I started tinkering around and it grew.


                          REQUIREMENTS/LIMITATIONS


Element Manager was written on a DTK Tech-1630 16 MHz 286 machine with 2 Mb
of memory, a math co-processor and a 40 Mb hard disk (28ms average access
time).

I'd recommend at a minimum:

8088/6, 80286, 80386 or 80486 processor
640K memory available
Hard Disk recommended
Printer optional

Just what environments the program will really run in I guess we'll all
find about real soon. This is the fourth release and so I expect I'll get
some feed back about this. However, the program was written to run in the
first 640K of memory. The program doesn't use any fancy graphics so it
should run on any monitor. It is possible to run the program in color.
Since there are no graphic routines nothing better than EGA should be
required for color operation. If you have a monochrome monitor, you can set
up the defaults to run the program in white on black or vica versa. Many
screens are formatted within the program for output to a display with an 80
character width and a 25 character height, so some laptops may have
problems. Quick Basic says that programs compiled in it's environment will
use a math co-processor if it is detected but will still crank along ok
without it. However, there isn't that much computing in the program so it
shouldn't make much of a difference either way.

Currently Element Manager is limited to files containing no more than 1000
element sets. I know there are a few folks out there with files larger but,
I was having lots of problems with memory management and 1000 sets was an
easy (and very reasonable) limit.

Using PKLITE you may reduce the executable file in size considerably. One
version of Element Manager required 302,722 bytes on disk. Using PKLITE
reduced the program to only 137,272 bytes. The program still works fine and
you save disk space. (Phil, if your reading, I use Stacker on my HD so
haven't licenced your nifty EXE packer.)

                              THE COMMAND LINE

Programs that allow parameters to be entered at the DOS command line are
handy as they allow for more automated processing. Element Manager takes
this feature seriously. You can accomplish quite a lot with this program
automatically by invoking it with lots of command line switches.

Usage:
ELEMAN [/Ifilename.ext] [/Ofilename.ext] [/Lfilename.ext] [/Sfilename.ext]
       [/A] [/B] [/C] [/E] [/F] [/H] [/M] [/N] [/P] [/V] [/X] [/Z]

  /I followed without a space by a filename designates the input data file.
  /O followed without a space by a filename designates the output filename.
          You may designate an EXTension to this name however the program
          defaults to use the epochday of the latest element set as the
          output filename's EXTension.
  /L followed without a space by a filename designates the log filename.
  /S followed without a space by a filename designates the satellite select
          file.
  /A forces AMSAT format output files.
  /B strips Plus Sign (+) replaces with Blank space.
  /C auto converts AMSAT to Nasa. You must supply /I and /O filenames.
  /E writes the age of Sats in inputfile to LogFile. You must specify input
  /F forces the output file to be created with the exact filename designated
          above instead of using Epoch day as the filename's EXTension.
  /H or /? will print this screen.
  /M defaults the colors to monochrome.
  /N forces Nasa 2-Line format output files. (default)
  /P starts the program in the auto mode. If a satellite select file is
          designated as described above it will be used.
  /V verifies and corrects the CheckSums of Elements. Only works in
          the /P mode. Must specify input filename with the /I switch.
  /X starts the program bypassing the configuration file.
  /Z sets checksum value of '+' to '2' otherwise it is '0'.


Above is the display you get if you enter ELEMAN  /H  at the DOS prompt.
Notice that you may leave NO spaces between the /I, /O, /L and /S switches
and their respective filename.ext's.

If you specify the /P switch you need to include an input filename via the
/I switch. Without it the program doesn't know where to find it's data. If
a select satellite File is omitted the input file is copied to the output
filename with the epochday of the most recent element set as the extension.
If you do include a Satellite Select File via the /S switch then only those
satellites contained in your Select file will be written to the output
file.

If you invoke the program with the /H switch anyplace on the command line, the
program will print the above help screen and return to DOS. So don't enter:

ELEMAN /Itle.txt /Onewele /Lother.log /H

The only switch that's recognized is the /H.

Element Manager will default the LogFile to ELEMAN.LOG. If you wish to name
it something else, then either use the /L switch to specify that filename
or change the configuration of the program to use a different filename.
Remember that the configuration file is only consulted when you run the
program in the "manual" mode. If you specify the /P switch to autoprocess
information then you must include any filename changes with command line
switches. The LOG file is opened at each invocation of the program. Just
about everything you do in Element Manager is recorded to the LOG file.
This file will be overwritten each time you start the program so, if you
have information you want to save, be sure to rename the file when you exit
the program.

If you don't want Element Manager to write output files with the epoch day
as the filename's extension, you can enter a filename with and extension
with the /O switch and invoke the program with the /F switch. /F will force
Element Manager to write the results of your run to the file name you
specify.

If you want to have Element Manager automatically extract a certain subset
of elements you must have a Satellite Select File available. More about
that later. Invoke the program with the /P switch and specify a Satellite
Select File with the /Sfilename.ext switch the program will process your
input file and extract elements from the file if they are found in the
select file and write them to the output file.

The /V option is available to verify and automatically correct the
checksums of the elements prior to a new file being created. If an element
set fails it will be corrected and the output file will be created. The Log
file will report that a failure occurred with one or more of the elements
in the input file and those satellites that fail a check will be listed.
This switch only works in an automated processing session. You can manually
verify checksums from within the program from the main menu.

In a related function, the /B option can be combined with the /V switch.
The /B will search the input file for plus signs (+). If any are found they
are changed to a blank space and the checksum is intentionally corrupted.
Then when the /V part of the program goes to work it will correct this and
any other checksum errors.

The /B switch can also be used when you aren't engaged in autoprocessing
the file. Start the program with it and when you select fix checksums from
the main menu, the program will first find and replace any plus signs with
blank spaces. Then it will proceed with the checksum fix routines.

The /C switch will automatically convert an AMSAT format input file to a
NASA 2-Line output file. You must specify the AMSAT file with the /I switch
and a filename for your 2-Line output via the /O switch. This option may
not be combined with other options. Element Manager only processes NASA
2-Line input files for output. So, you'll have to use this option to first
convert your AMSAT format files then run the newly created Nasa format
files for processing by Element Manager.

The /E switch will automatically check the Epoch age of the element sets in
the input file identified on the command line by the /I switch. This switch
will over ride any other switches except the /C switch which will take
precedence. If you add a number to the /E switch Element Manager will use
it to offset your system time to UTC. As element sets are given in UTC this
will result in a more accurate age analysis. The offset should be the
number of hours between you and UTC. For example, if you are in the ET time
zone of the USA and daylight savings time is in effect UTC is +4 hours from
your system time. If you live in the MT time zone and daylight savings is
not in effect the difference is +7. Just enter the number after the /E
switch (ie: /E7). However if your system time is set to a time zone east of
0 degrees longitude then you must enter the (-) minus sign (ie: for the
Middle East enter (/E-2)). If you use the /E switch to check the age of
element sets and do not enter an offset the program will use /E0. Offsets
may be entered in fractional hours. If you are located in an "odd" time
zone where your offset would be for example -4.5 hours the program will now
accept the fractional part of the offset. Automated procedures from the
command line bypass reading in the config file and so any default offset
won't be used.

The /M switch forces the program to use only black and white colors.

The /X switch forces the program to bypass the configuration file and start
the program in monochrome mode.

So, ... Lets say you have the file TLE.TXT containing all your elements.
You want to output a new file with the name VISUAL.TLE containing only
satellites you have determined are good candidates for visual observation
in your VISUAL.SEL file. And you want to check to see if all the element
sets you output pass a checksum verification. Finally, you want the output
file in AMSAT format. Enter the following on the command line.

ELEMAN /Itle.txt /Ovisual.tle /Svisual.sel /V /P /F /A

or you could enter:

ELEMAN /V /Svisual.sel /P /Itle.txt /F /A /Ovisual.tle

The program will run unattended and read in TLE.TXT, verify it is a proper
format file, check the checksums of the element sets, find all the
satellites that match those listed in your VISUAL.SEL satellite select file
and write out a new AMSAT format file named VISUAL.TLE containing only the
matching satellites. When it finishes, ELEMAN will return to DOS. During
the process ELEMAN will print status reports of the analysis on the screen.

As shown above the position and order of the command line switches is
unimportant. Mix them up any way you want.


                             INSIDE the PROGRAM


While Element Manager is a powerful tool when used from the DOS prompt
there are several things that you have to be inside the program to
accomplish. Creation of Satellite Select Files, editing element sets,
adding new element sets all require interactive input. And so, Element
Manager has a series of Menus to guide you to features you may want to use.


                                  MAIN MENU

1. Show Statistics of Input File
2. Write New file With Selection Criteria
3. Analysis of Age of Elements
4. Selection Criteria Menu
5. File Utilities Menu
6. Verify Checksums
7. Correct Checksums Write New File
9. Shell to DOS
0. Quit the Program

Above are the selections you may make at the main menu. Items may be
selected by either pressing the number associated with that option or using
the cursor keys to move the pointer to the item you wish to select. Hitting
the return key will select whatever item the arrow is pointing to. This
convention works for the Main, Selection Criteria and file Utilities Menus.

There is no indication within the program however, if you enter an "M" at
the main menu the Mean Motion / Inclination Filtering will toggle on/off.
If you enter "S" the Select Satellite Filtering will toggle on/off.

SHOW STATISTICS

If you select item 1 Element Manager will read your input file and show a
screen full of statistics about that file. Included in these statistics are
how many elements are in the file. What the latest epoch year and day of
the most recent element set is. How many satellites are at various Mean
Motion altitudes. How many satellites are at various inclinations. How many
satellites have a high drag factor. And how many satellites have a high
eccentricity. Each time you auto-process a file these stats are written out
to the log file, but you might want to examine them interactively with
several different element files.

WRITE NEW FILE

Item 2 of the Main Menu will write out a new file of elements. You can
write out a duplicate file of your input file however the program will not
overwrite an input file. If you get a message to this effect. Go to the
File Utilities Menu and change the output file name. Any selection criteria
which is set *** AND *** active will be used when you use both Items 1 and
2 of the Main Menu.

AGE ANALYSIS

Item 3 of the Main Menu will take you to a screen where the age
distribution of the elements in your input file are displayed. If you wish
to see the age of each satellite in the input file select the (W) option
from this screen and each element set will be analyzed and the age of each
satellite will be written to your LogFile.

note: The system date is checked for leap year status and this information
is incorporated in the analysis. However, the year of the element set is
not checked for it's leap year status. So, if it's 1/1/93 (not a leap year)
and you check the age of and element for day 31 of 1992 (a leap year),
you'll come up one day short as the program doesn't know about 2/29/92.

SELECTION CRITERIA

Item 4. Suppose you wish to create a file with element sets of only those
satellites with mean motions of 15 or greater (low orbiting birds). Or
perhaps you live in northern (or southern latitudes) and wish to have a
file of only those satellites that might pass overhead of your location. By
selecting item 4 on the main menu you will be taken to the Selection
Criteria menu. Once there you may enter the maximum and minimum parameters
for these two factors. This menu also contains the toggles to turn on and
off the selection process. You can set a minimum mean motion of 13 a
maximum of 15, a minimum inclination of 39 degrees and a maximum of 141
degrees but if you don't toggle the filtering on it won't take effect if
you either use Item 1, or 2 of the main menu. In the default parameters box
at the bottom of each screen you will be informed of the status of this
toggle.

If you have a Satellite Select File loaded you must have the Select
File toggle on for it to be used at each of the first two items of the main
menu. However, whenever you load a Select file that toggle is automatically
placed in the on position. But, you may have a Select file loaded and wish
to view the complete statistics of an input file. You can come to this menu
and toggle the Select File toggle off. The Select File will still be
available however it will not be used in the statistical analysis portions
of the program.

Item 5 of the Main Menu takes you to the File Utilities Menu. This menu
offers lots of options.

VERIFY CHECKSUMS

Item 6 of the Main Menu will verify the values of the Checksums in your
input element file. No corrections are made, the program just reports on
any discrepancies.

CORRECT CHECKSUMS

Item 7 of the Main Menu will check the values of the Checksums and corrects
any discrepancies. A new file will be output under the name FIXCHECK.TLE.

SHELL TO DOS

Item 9. This option allows you to SHELL to DOS. When finished in DOS type
EXIT and you will be returned to the Main Menu.

Item 0. This option quits the program and returns you to DOS.

Note: The [ESC]ape key will move you "up" one stage in the program. If you
are at a sub-menu you will return to the previous menu. From the Main Menu
you'll be returned to DOS.


                            FILE UTILITIES MENU

1. Load Input Data File
2. Load Satellite Select File
3. Change Log File Name
4. Change Output Data File
5. Create Satellite Select File
6. View/Edit Satellite Element File
7. Check Input File for Duplicates
8. View/Edit Configuration File
9. Convert AMSAT format Elements to Nasa 2-Line format
V. File Viewer
0. Return to Main Menu

LOAD OR CHANGE FILENAMES

Options 1 through 4 are self explanatory.

For each of these selections a directory of files currently available to
the program will be displayed. When you choose to change or create a
Satellite Select File the program defaults to showing a directory of only
those files with ".SEL" as a file extension. When you select the change log
file option, the program shows only those files with ".LOG" as a file
extension. Input and output selections return a listing of all files in the
directory. If you wish to see a listing of any other files at any of the
first 5 menu selections of the File Utilities Menu, simply enter a wild
card filename and the program will show all files that match your entry.
IE: entering *.* will list all files in the directory, entering
\dog\cat\*.pet will display all files in the \dog\cat subdirectory with a
file extension of ".PET". Follow DOS rules for wildcards.

----------
IMPORTANT
----------

Whenever you enter wildcards to view different directories of files
QuickBasic will ALWAYS show the default directory at the top of the
listing. So, if you are in the \dog subdirectory and enter \dog\cat\*.PET,
Element Manager will print out something like:

C:\DOG

HOUSE.PET    TABBY.PET     PERSIAN.PET

12123321 bytes free

Don't be confused by this display. You will really be viewing the directory
of \dog\cat. Also notice the bytes free message.

Enter the name of the new file you wish to use. You may enter a fully
qualified filename as described in the ".PET" example above however,
Element Manager will only display the last 12 characters of a filename.
This results in a somewhat sloppy display of filenames but accurately
reflects at least the actual filename. For example, in the pet example, if
you loaded the file \dog\cat\tabby.pet all the default filename displays in
the program would show "at\tabby.pet".

Loaded files will be checked for formatting errors where appropriate and if
they pass the test the File Utilities Menu will reappear. If they fail the
tests, a message appears on the screen indicating the type of failure. File
too large, bad format, non-existent file etc. If you change your mind and
wish to leave the currently active files intact just hit return without
entering a filename. You'll be returned to the menu. If there are more
files than will display in the window, the first few files will scroll off
the top of the screen. Sorry about that but the solution to this problem
caused many more. Perhaps a fix will be in the works in the future. In the
meantime, use wildcards to reduce the number of files displayed.

A few things about item 1. Anytime you attempt to load an Input Data File,
Element Manager will check that file for proper formatting. If it fails the
checks mentioned in APPENDIX B - BADLY FORMATTED FILES two new files will be
created. They are FIXED.TLE, containing the cleaned up elements and
FAILED.TXT containing any badly formatted element line and any text not
belonging to a two line element set.

If the file passes the initial tests as described in APPENDIX B - BADLY
FORMATTED FILES but contains blank lines within the rest of the file,
you'll be presented with an error message indicating this failure and the
file will not load. Check the filename to be sure you tried to enter an
actual NASA 2-Line file.

If any element sets after the first set fail the checks described in
APPENDIX B then Element Manager will post a notice on the screen and list
any sets that fail in the LogFile. The program will still load this file.
As described in APPENDIX B, if you wish to correct these errors it is
necessary to insert a blank line or some other error at the beginning of
the file (first three lines) to force the program to go to the fix-it-up
routines.

Two possible errors that can be repaired involve the "English" satellite
name. If the name is missing (a blank line preceding a 2-line set) or if
the length of the satellite name is equal to or greater than 69 characters
then Element Manager can create a new "English" name in one of two ways.

The preferred method of correction involves using the SATNAME.DAT file that
comes with the program. If this file is present then the correction
procedure will check it to see if there is a matching catalog number for
the Element set in the input file with a bad or missing name. If it finds a
match it will substitute the name found in the SATNAME.DAT file for the one
Element Manager currently thinks belongs with the input file's 2-line set.

The second method of correction involves substituting an error message for
the satellite name. This second method may create element files that will
not be acceptable to some satellite programs for updating purposes because
they use the satellite name to identify an element set for updating
procedures. For more info on the correction procedures see APPENDIX B.

Once the file has been created, it will be loaded. So, if you ask for
TLE.TXT to be loaded and the program informs you it is correcting the
element file and returns to the menu indicating the default Input Data File
as FIXED.TLE, don't be surprised.

CREATE SATELLITE SELECT FILE

When you pick item 5, the program starts up the Create Satellite Select
file routines. Element sets will be displayed on the screen. You can scroll
up and down through the loaded element file. If you see a satellite you
wish to add to a Satellite Select file press (A) for add. Perhaps you wish
to give the satellite a different name than the one supplied in your
element sets. Press (E) for edit and you can enter any name up to 20
characters (some programs will only read the first 11 characters of this
line as input but you might want to use a more descriptive name). To move
up in the file press the up arrow key on your cursor keypad or enter (P)
for previous. To move down through the elements press the down arrow or (N)
for next. If you wish to create a file with all the elements listed press
(G) for Get all remaining satellites. If you use the (G) option it will
pick up the currently displayed satellite and all those listed below it in
the element file. If you wish to create a "master" select file comprised of
all element sets make sure you're at the top of the file before pressing
(G). When you are at the top of the file you will be advised by a message
at the top of the screen. Likewise for the bottom of the file. The current
element set is displayed in the status box at the bottom of the screen. You
will notice that data files and select files have numbers following them in
this box. These numbers reflect the total number of satellites in each
file. The Satellite Select filename's number counter will increment each
time you add a satellite.

Here is a sample of the contents of my Amateur Radio Select file.

14129:OSCAR 10
14781:UoSat 2
19216:AO-13
18129:RS-10/11
20437:UO-14
20438:UO-15
20439:PACSAT
20440:DO-17
20441:WO-18
20442:LO-19
20480:FO-20
21087:InformTR
21089:COSMOS 2123

I could import this file into a text editor and make some changes:

14129:OSCAR-10
19216:OSCAR-13
14781:UoSat 2
20437:UOSAT-14
20438:UOSAT-15
20439:PACSAT
20440:DOVE
20441:WEBER OSCAR
20442:LUSAT
20480:FUJI OSCAR-20
21087:AO-21
18129:RS-10/11
21089:RS-12/13

Notice that the elements are in a different order and some Satellites have
different names.

When Element Manager uses a Select Satellite file it only uses the 5 digit
Catalog Number to find matching satellites. So, you can change the
descriptive text name of the satellite and you will still be able to use
the file. When a new file is created using a Satellite Select File to pick
out individual birds, the text name of the satellite in the input file is
replaced with the name used in your select file. The order of satellites in
the output file in the same order they appear in the select file.

Two Select Satellite Files are included for your experimentation. They are
SEMIVIS.SEL and VERYVIS.SEL. These files were created from the file
QUICKSAT.MAG taken from Mike McCants' program of that name (available on TS
Kelso's BBS under the name QUICKSAT.ZOO). They contain satellites that
should make good candidates for visual observation. You will notice a
number after the Satellite Name. This number is the intrinsic magnitude as
given in QUICKSAT.MAG. It is supposed to represent the apparent magnitude
of a satellite at a range of 1000 kilometers. The files are sorted first by
magnitude and secondly by Catalog number.


VIEW/EDIT SATELLITE ELEMENT FILE

The Satellite Element Selector/Editor section of the program offers the
capability to view or edit individual element sets, sort the element file
and search the input file for a particular satellite by it's name. When you
first enter this screen you will be presented with a listing of the first
39 satellites in the file. The first satellite will be highlighted. Using
the Home and End keys on the cursor keypad you can move to the top and
bottom of the file (respectively). Using the up and down arrow keys will
move the highlight bar toward the beginning or end of the file. Using the
left and right arrow keys will move you from one column to the next.
Pressing the page down key moves you one screen (39 satellites) down the
element file. Pressing the page up key moves you to the previous screen of
elements.

Selecting the (S)ort option Element Manager will take you to another screen
where you can view the input file. At the bottom of the screen are various
selections for sorting the input file. By selecting the letter in
parenthesis the file will be sorted by either the English Satellite (N)ame,
(E)pochday of element set, (D)rag, (I)nclination, (A)rg of Perigee, Mean
(A)nomaly, (M)ean Motion, (C)atalog Number, Epoch (O)rbit or Element Set
n(U)mber. Selecting (R)estore Original will reload the original input file.
If you wish to exit this screen without creating a new file enter either Q
for (Q)uit or press the [ESC]ape key. If you wish to create a new file from
the results of the sort press S for (S)ave. Element Manager will write the
file SORTED.TLE which contains the results of your sorting operation. If
you save a sort then the program will load that file when you return to the
Satellite Element Selector/Editor screen. Otherwise, the original file will
be used. If you have resorted the file and wish to return to the original
sorting press S for (S)ort again and select (R)estore. Your original input
file will be reloaded.

The sorting procedure is some what slow. On my machine (16MHz, 286) it
takes about a minute to sort an element file containing 526 element sets.
Most files you'll be using will probably be substantially smaller so this
shouldn't be too much of an inconvenience. Slow or not, it beats not having
the feature avaliable so -- be patient (grin).

Element Manager can search the input file for a particular satellite.
Selecting the (F)ind Satellite option will cause the program to prompt you
for a string of text to search for. Enter any text at the prompt and the
program will scan the file for any occurance of that text. Both the line of
text containing the English Satellite name and the associated NORAD catalog
number are searched. If you are looking for Akebono (NORAD cat # 19822)
enter:

AKEBONO
akebono
AkEbOnO
aKeBoNo
19822
etc.

Element Manager will start the search operation. The highlight bar will
travel along (on screen) thru the file until it finds the satellite. Notice
that the program is case insensitive. When the satellite is found a notice
is posted at the bottom of the viewing window. You are also prompted to
either continue the search by entering "N" for next occurance or aborting
the search by hitting any other key. If you abort, the highlight bar will
remain on the found satellite. If you press "N" the highlight bar will
continue thru the file looking for the next occurance.

If you are unsure of the exact spelling of a satellite name but have a good
idea about a part of the name then you can enter that part and the program
will search as above looking for any occurances of the text. In the example
above if you enter:

ake
keb
bon
ono
822

the program will stop on all satellites that contain that text as part of
the name or catalog number. If there is a satellite in the file named Yoko
Ono then that satellite will stop the search. In the case of a search on
822 the program may find DMSP B5D2-4 (NORAD Catalog #18822) instead of
Akebono. If this isn't the satellite you are looking for, press "N" when
prompted and the search will continue. Eventually you'll find Akebono. So
you could just enter "A" as your search term. But, all satellites that have
the letter "a" anywhere in the satellite name will match the search making
it somewhat ineffective.

If the text you search for is not a part of any name or catalog number
contained in the file then Element Manager will inform you that it did not
find the satellite you were looking for. This notice is also posted if you
find a satellite, continue the search and do not find any subsequent
occurances of the search string.

Each time you enter a name or catalog number to search for, the program
stores that text. The next time you enter the search function, that text
will serve as a default search string. In this way you can research the
file with the last search term by simply hitting the return key when
prompted for a search string. This text will also appear on the prompt
line. If, for example, you search for Mir. The next time you enter the
search function the program will prompt you to:

Enter the satellite name/Cat # to search for (Last: Mir):

If this was your first search, the (Last: Mir) part of the prompt would not
be present on the prompt line. If at this prompt you entered Akebono the
next time you started a search the prompt would read:

Enter the Satellite Name/Cat # to search for (Last: Akebono):

You get the idea.

You can select an individual satellite or a group of satellites to write
out to a new file. You can select an element set and view, edit and print
the parameters of that set. In a related function, you can add a new
element set to those in memory. One idiosyncrasy of this part of the
program, you MUST load an existing element file to get here. So if you wish
to create (Add) element sets you have to start by loading an existing
element file. You need not save all the old elements. Once you've added one
or more new element sets just mark those sets and Save the file.

VIEW, EDIT OR PRINT ELEMENT SET

To view an individual satellite element set, highlight that set and press
the enter key. The program will switch to another screen that displays the
full element set in two formats. At the top of the screen a Nasa 2-Line
depiction will appear and to the left of the screen the AMSAT format will
be displayed. To the right of the screen are displayed various derived
values from the element set.

The first value displayed in the Derived Values area is the "Reference
Time:". This time is calculated from your system clock time and date. If
you have any OFFSET entered in the program configuration it will be figured
into this time.

The second value displayed is the "Reference Epochday:". This is the NASA
style format of the Reference Time.

The first and second values listed above are calculated at the time you
enter the Element Editor screen from the Editor/Selector screen. If you
wish to update these times, simply return the Editor/Selector screen
and re-enter the Edit Element screen.

The third value displayed is the "Elem. Set Age:". This age is computed by
comparing the Reference Epochday with the EpochTime of the element set. If
the offset is properly set, it will be an accurate representation of the
age of the element set. If the element set is greater than 16 years old or
if the element set refers to a date more than 3 years in the future when
compared to the computer's system time and date then a message indicating
the age is out of range of Element Manager's ability to calculate that age.
No other calculations are affected by a "strange" element set date.

The fourth value displayed is the "EpochTime:". This is the "English"
format time of the epoch date in the format  MM/DD/YY HH:MM:SS.ssssss.

The fifth and sixth values displayed are, respectively, the Perigee and
Apogee altitudes of the orbit in kilometers. These altitudes are calculated
over the mean surface of the earth. No account is taken of the equatorial
bulge. So, the altitudes are commonly off by several kilometers. In the
case of the AO-10 element set given above, the algorithms working inside
Element Manager give a perigee altitude of 3,893 kilometers while Graf Trak
indicates 3,890 kilometers. A three kilometer difference. The Apogee height
of AO-10 as computed by Element Manager is 35,565 kilometers. Graf Trak
indicates 35,562. Another 3 kilometer error. As you can see these
variations are minor and for the purposes intended in Element Manager I
believe that they are accurate enough to give you a real feel for the shape
and size of the orbit. For more accuracy, use your prediction programs.
They must figure in the bulge in order to accurately predict a satellite's
location. To convert these figures to statute miles divide by 1.609 (the
number of kilometers in a mile). The algorithms for these determinations
were taken from "The Satellite Experimenter's Handbook" by Martin Davidoff
(chapter 11, table 11-3).

The seventh value displayed is the "Orbit Period:". These figures are
calculated from the Mean Motion and indicate the time it takes the
satellite to complete one orbit.

The eighth value displayed is the "Est. Age:". These figures are calculated
from the epoch orbit divided by the mean motion. Some satellites have
incorrect Epoch orbits. So, you may get strange results. However, I like
having this computation available. If it looks wrong, it probably is. Check
the Epoch orbit number and if it's obviously incorrect that's your problem.
Just ignore it. These displayed ages have nothing to do with creating or
editing element sets. They're just there for your enlightenment. As with
the "English" epoch day display above, the age figure is calculated for the
epoch day of the element set. No compensation is made for time passed
between the creation of the element set and your system time. This screen
is handy for examining element sets. You can use the arrow keys to move
forward or backward in the element file one satellite at a time.

If you wish to print a displayed set, make sure your printer is on and
press (P) for (P)rint. Element Manager will print the element set along
with its derived values. If you wish to print successive sets just move to
them and press (P). Element Manager will print 3 element sets to a page
(one at a time). If you want only one element set per page, you may press
(F) for (F)orm Feed. The program will issue the form feed to the printer.
If you have printed element sets,  when you exit from the Selector/Editor
area of the program it will issue a form feed to eject the last page of
printed elements. If your printer is off, out of paper or not ready in some
way, Element Manager displays NO error messages and acts like it has
printed that set. So, check the printer, correct any problems and try
again. I tried to get an error message to display but have been having some
problems with the error trap. The program will recover but won't tell you
why the printer didn't work.

note: I only have a Panasonic KX-P1124 printer so I can't vouch for the
printer routines with other printers. An IBM ProPrinter X24 won't be a
problem as the codes used are the same.

If you wish to edit a set press (E) for edit or press the return key again.
The derived values at the right of the screen will disappear and an arrow
will appear to the right of the AMSAT format elements. Using the up and
down arrow keys will move this pointer. When it points to the parameter you
wish to change press return again and you'll be in the editing mode. To the
right of the parameter you wish to change a highlighted field will appear.
The length of this field is the maximum length of the data you may enter.
If you make some kinds of mistakes Element Manager will recover. For
instance if the current inclination of a satellite is 123.7763 degrees and
you wished to change it to 75.1 degrees you need only type in 75.1 not
075.1000. The program will fill spaces in front and zeros in back of any
entry you make to fit the information into the nasa 2-line format. If you
enter a number that is out of the bounds of a parameter it is rejected. Any
degrees less than 0 or greater than 360 won't be accepted (for inclination
the values must be between 0 and 180 degrees). The catalog number MUST be a
5 digit number. If you have a set of elements that indicate a catalog
number of 464 add preceding zeros when you enter it (ie: 00464). When you
type the return key the information you've entered will appear in the
2-Line element set at the top of the screen. Most formatting errors are
detected and rejected with a notice posted on the right side of the screen
indicating the error made in entering the data. Throughout the editing
process only the NASA 2-Line element set at the top of the screen will
reflect any changes you've made. The old elements will remain in position
at the right in the AMSAT format display.

DRAG - Sometimes you'll notice that the drag figure for a satellite is a
(-) minus number. This usually results from the element sets being created
when the satellite in an unusual position where the gravitational effects
of the Sun and Moon are actually combining to elevate the apogee of the
orbit. This drag factor is a legitimate number however, it only works as
long as the Sun and Moon continue to affect the satellite in this manor. If
you have an old set of elements you might want to replace this figure with
a "0" drag.

ECCENTRICITY - There is really no such thing as a true circular orbit. So
every satellite has some eccentricity. However, in some cases it is a
really small number (smaller than can be indicated by the 2-Line format). I
have found that at least one program I use will NOT tolerate a zero for
eccentricity. If you get errors using a program where a divide by zero
overflow is indicated, change this figure to .0000001 and your problems are
solved.

Normally the length of the blank field to the right of the parameter you
wish to edit equals the maximum length of a possible entry. In the case of
the Epoch date field, there are two accepted formats in use. One, the
traditional NASA format, includes the epoch year, followed by the epoch day
and fraction of day. It looks something like this:

91012.25000000 or
91 12.25000000   (Element Manager doesn't mind a space)

This entry would be for January 12th 1991 at 6 am UTC. The maximum length
for this type of entry is 14 characters, 5 for the year and day, 1 for the
decimal, and 8 for the fraction of a day.

Another format in use is the one used in QuikTrak. In order to keep those
folks happy, you can also enter the same information into the program in
the following format:

01/12/91 06:00:00.000000

or

01-12-91 06:00:00.000000  (dashes instead of slashes are ok)

It is "imperative" that, should you elect to use this entry format, you
follow the conventions exactly. In other words:

1/12/91 6:00

will not work. There are two errors that the program will not accept. One,
the month is not a two digit number. You've got to use that leading "0" or
the program will inform you of a bad format for your entry. The second
error is the lack of any seconds. You have to completely fill out this
template or the program will reject your entry. Should you forget the
format, refer to the "English" display of the epoch day that is displayed
prior to entering the editing mode or enter a badly formatted day and the
program will come back with a reminder of the correct way to get info into
the program.

Because the QuikTrak format requires more spaces it was necessary to relax
the length check of the input information. So if you enter a NASA style
epoch day that is too long you won't be reminded of your error and any
numbers entered after the 14th place in the entry will be discarded. No
rounding will occur, they will just be stripped. If you exceed the length
of the QuikTrak format you'll still get an error message.

I know it might be easier to check entries from the amsat format element
set however, changing only the 2-line set has two advantages. First if some
dramatic formatting error occurs, you'll see it. Secondly, you learn what
each of those numbers means. You are still in the editing mode and can use
the up and down arrows to move the pointer to the next correction you wish
to make.

When you are finished entering changes, you can either exit from the
editing menu without saving any changes by pressing the [ESC]ape key or (Q)
for quit. Element Manager will exit the editing screen with no saves and
restore the 2-line display at the top of the screen to the original values.

Pressing the (S) for save key will save your changes and update the AMSAT
format display to reflect the new values.

THIS IS IMPORTANT!!!!!

When you save these changes you've only changed the elements as they appear
in the computer's memory. You'll need to return to the selection screen of
the Edit Elements area to save the elements to a file permanently.

Once you leave the edit mode you are still presented with the single
element screen. You may either hit the [ESC] key to return to the selection
screen or use the arrow keys to move through to view, edit or print other
element sets. When you are finished, editing hit the [ESC] key. You return
to the selection screen.

From here if you enter (S) the program will save any satellites you have
marked into a new file.

THIS IS IMPORTANT TOO !!!!

If you have not marked any element sets, then no sets will be saved. Move
the highlight bar to a satellite you wish to save and hit the (T) for
toggle key. An arrow will appear beside the satellite you picked. Using the
(M) toggle you may toggle all satellites back and forth BUT remember this
is a TOGGLE. If you have 20 satellites if a file, have ten of them marked
and hit the (M)arks toggle key those ten marked satellites will clear.
HOWEVER, the other ten unmarked satellites will become marked ones. The (C)
for clear marks key was created for this eventuality. If you wish to mark
all satellites and have a few already marked, hit the (C) key and all marks
will clear. Then hit the (M) key and all satellites unmarked will be
changed to marked (all the satellites).

If you have a set of element for a bird and wish to create a NASA 2-line
set of them. Use the (A)dd key. A dummy record will appear at the end of
the currently loaded element file and be highlighted. Go to the editing
screen and edit the template of this set with the new elements. Once the
element set has been entered use the (S)ave option in the element editor
and then return to the Selector screen and mark the new element set and any
other elements you want in the new file and press (S)ave again to write the
changes made in memory to a new disk file.

If you just want to experiment with various possible orbits, you can (A)dd
a new element set, go to the editor and enter various values. When you save
an element set from the editor screen NO changes are actually made to your
input file. However, the new values you've entered will be displayed and
epoch age, "English" format time and Apogee and Perigee Altitudes will be
calculated for the set. If you were only "playing" around just [ESC]ape
from this section of the program and those play element sets will be erased
from memory.

CHECKSUMS

When you edit an element set you've invalidated the checksum. Element
Manager realizes this and computes a new one before writing the output
file. Actually, the program verifies Checksums for all element sets and
fixes any that are incorrect. This new checksum does NOT appear on the
editing screen. It is processed while the elements are saved to a file.

CHECK FOR DUPLICATES

Suppose you have lots of small files of elements and wish to create one big
file containing all the elements. But, some sets are duplicated in each of
the different files. Copy them all together. Make sure there are no blank
lines (proper 2 line format) and then use this option from the File Utility
menu. Element Manager will detect duplicates and output a new file named
NODUPS.TLE containing only the most recent set of elements for each
satellite. If no duplicate sets are found NODUPS.TLE will automatically be
deleted at the end of the run. This process is a bit tedious as the
program has a lot of work to do and so is the slowest area of Element
Manager. Remember that Element Manager can only handle a maximum of 1000
element sets. So, your combined file must not exceed this limit.

VIEW/EDIT CONFIGURATION

Element Manager is supplied with two configuration files. ELEMAN.CFG (the
required filename) is a color setup. MONO.CFG is a (guess what) a
monochrome setup. If you don't like these settings don't worry, just follow
the instructions below and Element Manager will create or modify the CFG
file to suit your particular preferences.

If the CFG file gets messed up simply erase it. Element Manager will next
start up notifying you it's missing and run in monochrome mode. Using the
steps outlined below you can recreate it.

Element Manager starts with many default options. You may set these options
any way you wish. By selecting item 8 from the File Utilities Menu you'll
be taken to the configuration editor.

The first item on the Configuration Editing Screen is the offset to
compensate for the difference between your system time and UTC. As element
sets are given in UTC using an offset will result in a more accurate age
analysis. The offset should be the number of hours between you and UTC. For
example, if you are in the ET zone of the USA and daylight savings time is
in effect UTC is +4 hours from your system time. If you live in the MT zone
and standard time is in effect the difference is +7. However if your system
time is set to a time zone east of 0 degrees longitude then you must enter
the (-) minus sign (ie: for the Middle East, enter "-2"). Offsets may be
entered in fractional hours. If you are located in an "odd" time zone where
your offset would be for example -4.5 hours the program will accept the
fractional part of that offset.

Normally there is no default input datafile. However, perhaps you always
work with a file of the same name. You may set this name. Each time you
start Element Manager this file will be used. You can still over ride this
setting by using the command line switch /I. To change the default use the
up/down keys. Highlight Default Input Filename and press return. You may
enter a new filename. If you enter nothing, you'll be prompted to erase the
existing filename or continue. Entering [ESC] or (E)rase will blank the
field. Anything else will retain the previously entered filename.

If you wish to set a default output filename follow the same procedure as
for a new input datafile.

There are still some folks out there who like their elements in English.
Frankly, I'm one of them. But I really only want to see them in English
once in a while mostly I'm happy to use the more compact 2-line format as
it transfers faster. However, for those of you who just have to have AMSAT
format element sets. You may use this option to output the results of any
actions of Element Manager in either the 2-Line or AMSAT formats. It's a
toggle. Just press enter and it'll change back and forth. When saving
element sets from the Selector/Editor area of the program, the Amsat format
toggle is not active. If you wish to write out those element sets in the
AMSAT format you'll have to return to the File Utilities Menu, load the newly
created element file, make sure you've got the AMSAT output file toggled on
in the configuration Menu and return to the Main Menu and select Item 2
write a new file. Or you might just return to DOS and use a Command line
entry something like this:

ELEMAN /Inewele.txt /Oamsat.ele /A /P /F

Assuming your new element sets are named NEWELE.TXT and you want to create
an AMSAT format file named AMSAT.ELE. The /A tells the program to write out
the elements in AMSAT format the /P tells the program to auto-process the
files and the /F forces the "ELE" file extension for the output filename
rather than using the epoch day of the most recent element set in the input
file.

The program was written to output files with filename extensions of the
epoch day of the most recent element set in the file. If you wish to take
advantage of this feature set this option to yes. If you want the output to
go to the filename and EXTension you specify in default output instead, set
it to no. This is a toggle. Just hit the return key and it will change from
yes to no.

You may change the log file name. Follow above described method.

You may enter a default Satellite Select File filename. Use above
procedures to enter and change.

You can force the program to always use a Satellite Select File. This is a
toggle. Press return and it changes back and forth from yes to no. If you
do not have a default Satellite Select File named in the option above, this
option will default to no.

The program has default parameters for Mean Motion and Inclination built
in. If you wish to change them do it here. Use the same methods as above.
However, you can't erase the field completely. You MUST have something set.
If you want to set it to pick up all satellites just use a Mean Motion of
".1" to 18 and an inclination of 0 to 180. That will cover all satellites.
Why you'd do this I don't know. If you toggle this filter off from the
Selection Criteria Menu this is what you end up with anyway.

If you set new default parameters for MM and Inc, you'll find them active
when you return to the Main Menu. These new default parameters won't really
become active until you restart the program. If you go to the Selection
Criteria menu and select Restore Defaults the original defaults that were
in effect when the program was started will be returned. This is due to the
way in which the default parameters are initialized during program startup.

Color -- Color options have changed in Version 1.5 of Element Manager. This
means you need to delete any old CFG files and create a new one. Otherwise
the program crashes and writes out an error message indicating input past
the end of a file. When Element Manager starts up without finding a CFG
file it sets itself in the monochrome mode. Just go to the VIEW/EDIT
Configuration screen and reenter any defaults you wish.

The color operation of the program is divided into three catagories. First
there are the border lines. Second is the text referred to as "Menu" text,
however, it's really the text surrounded by the border lines. Actual menus
appear in the main window. Third, the main window. Each of these areas can
be set to use a different foreground and background color. I set the
program in a white text on blue background for the main window, the border
lines to bright white on a red background and the Menu text as bright
yellow on red. You might prefer Black text on a white background (paper) or
something else. To use change colors move the highlight bar to either Main,
Menu or Border default color selection. Press return and a sample window
will open at the bottom of the screen. Using the up/down arrow keys you can
scroll through the foreground colors. Using the left/right arrow keys
scrolls through the background colors. (16 foreground colors, 8 background
colors). The colors identified beside each default setting are given in the
format:

FOREGROUND+BACKGROUND

Don't miss interpret this to mean that the colors are somehow being added
together.

IMPORTANT !!!

After you have changed any of the defaults presented in this menu you must
use the (S)ave option to create a new ELEMAN.CFG file. If you just [ESC]ape
from this menu any changes you have made will not be implemented in the
.CFG file and will be lost.

Using the (S)ave option will both save any changes you make to the CFG file
and immediately be implemented in the program.

If you just want to check out the current defaults exit from the
configuration editor with the [ESC]ape key. This will retain any settings
currently active in the program.

If you start the program with switches to designate files other than the
default .CFG files and wish to bring back the defaults, just go to the
configuration editor, (S)ave the existing configuration without any changes
and those defaults will replace any options you specified via the command
line switches.

The program doesn't require the presence of a configuration file. However,
each time it is started without it you will be informed that it is missing.

CONVERT AMSAT TO NASA 2-LINE

This program works almost exclusively with NASA 2-Line files. But because
there is another format out there, I've dealt with it. As mentioned above
you may use Element Manager to create AMSAT format element files. But,
suppose a friend offers you some elements on disk, via modem or whatever
and horror of horrors, it isn't in 2-line format. Using this option you may
read in a file containing elements in the AMSAT format. Element Manager
will write a new file of 2-line elements from the source file. Naturally it
will add a checksum for each element set.

The only checking Element MANAGER makes is to look for enough of a name to
identify it (first 3 characters of a record except for "Mean A" and "Mean
M" to distinguish between those two records. Next Element Manager looks for
a colon. Whatever follows the colon and where ever it is on that line the
program uses as that parameter. any trailing alpha characters (deg, rev
etc.) are discarded. In the case of the decay factor, the program looks for
possible exponential notation and recognizes it if found. So the decay rate
listed below could also be listed as 7.2e-07 and would be accepted and
translated.

note: When Element Manager creates AMSAT format element sets it never uses
exponential notation.

Satellite: OSCAR 10
Catalog Number: 14129
Epoch Time:      91312.44187316
Element Set:     776
Inclination:       25.9057 deg
RA of Node:       115.4097 deg
Eccentricity:    0.6067273
Arg of Perigee:   291.5986 deg
Mean Anomaly:      16.1497 deg
Mean Motion:    2.05882356 rev/day
Decay rate:     -.00000072 rev/day^2
Epoch Orbit:     3521

Element Manager doesn't care what comes along with the AMSAT format element
sets in the input file. That file can be a capture from a BBS, CIS etc.
Message headers, message text and any other extraneous material is skipped
over. The only checks it makes are as follows. If a line begins with "SAT"
as the first three characters (case insensitive) then the program believes
it has discovered the first line of an AMSAT format element set. It then
continues reading that line looking for a colon (:). If no colon is found
on that line then Element Manager thinks there is NO satellite name. If a
colon is found the program could be temporarily fooled by something like:

Satellites that are in low orbits (IE:Mir) are more susceptible to
atmospheric drag.

Even though it obviously isn't really the first line of an AMSAT format
file the program believes it has discovered an element set. The program
would think that the name of the satellite was "Mir) are more susceptible
to". Regardless of the program's finding of a colon, it then continues to
process that line. It then examines the next line. Seeing that the line
does not begin with "CAT" it would fail that element set and continue down
the file looking for "SAT" again.  In the unlikely event that the next line
of the file actually did begin with the letters "CAT" it would perform the
above procedures. At some point these coincidences have to break down and
the element set fail. When that occurs, an error counter will increment by
one and when the file finishes processing you will be informed that errors
were detected. The LogFile will list the number of errors detected. This is
a false error and if no errors were detected in actual element sets you'll
still have them all converted to the 2-line format and read out to the
output file.

This test is made on each line of an actual element set. So if there are
blank lines, an element set is incomplete, it is listed in an order other
than the one specified above then that set fails, it is skipped and the error
counter will be updated and you'll be notified in the program and the
number of errors will be indicated in the LogFile.

If you want to test this feature out, just convert this file (ELEMAN.DOC)
from AMSAT format to NASA 2-Line. Only the above Oscar 10 element set will
appear in your designated output file. There will be somewhere in the
neighborhood of 20 errors listed. In this edit of the doc file I'm now
working on there are 22 occurrences of SAT in columns 1 through 3. Running
Element Manager against the DOC file extracts the one valid element set and
reports 21 errors.

FILE VIEWER

I've added a really simple file viewer to the program. It has lots of
limitations, however, I think it's a worthwhile addition. Files must be
text files. Lines within files must be 80 characters or less in width (> 80
characters truncated). Files must be less than or equal to 2500 lines in
length (entire file is placed in memory for easy manipulation).

There is a search function available. Enter "F" for find and you'll be
prompted for a string to search for. The search function is case
insensitive. If you are located at the top of the file the program will
begin the search with the first line of the file. However, if you move down
into the file, the search will start on the second displayed line on the
screen. When a string is found the viewer will display the line containing
the hit on the first line of the viewer in reverse video.

To continue searching through the file for further occurances of the search
string hit "A" for again. When no further occurances of the target string
are found a message will be posted on the bottom status line of the screen.
The display will remain at the location of the last hit.

Hitting "R" searches backwards (reverse) through the file for occurances of
your search string.

I found I was frequently exiting Element Manager to view the results of
some actions that were only written to the LOG file. This option allows for
quick access to that file.

That's it for the File Utilities Menu.

                               MISCELLANEOUS

If you detect problems (bugs) and wish to report them I can be contacted at
the Celestial BBS under the user name RICHARD VONGLAHN (no space).


                                 WISH LIST

For Element Manager:
Coming to Element Manager someday.

Intelligent element corrector (say what). Ever had a prelaunch set of
elements for the Shuttle only to have the bird get off the ground late.
Well it should be pretty easy to code an updating feature that allows
everything about the orbit to remain the same but those features that
change due to late launch. I'm looking into it.

For a nifty Satellite Tracking program:
How about it you programmers out there. I'd like to see you implement
something like the program NASA uses to display the shuttle in its orbit at
JSC. That display is really something else.

Instead of a mercator projection with a little cross marching up and down,
they have a spherical projection of the earth with a little depiction of
the shuttle (in it's current attitude) "flying" along in it's orbit. They
can position a look angle to watch the shuttle from above, ahead of or
behind the shuttle. The orbit is drawn as a line suspended above the earth.
Instead of moving the plotted position of the satellite in question along
the map, they keep the satellite in a constant position and redraw the maps
to show it's new position. It's just the cat's meow for displaying an
object in orbit. I realize we couldn't get realtime data on attitude but,
fudging a bit might produce suitable displays. When the shuttle is in a
gravity gradient attitude holding position or locked on a fixed position on
the celestial sphere it should be easy enough to fool the program into
displaying a "realistic" attitude for the orbiting object. For objects like
OSCAR 10 and 13, Blon and Blat should be able to fix the attitude. For
other satellites, like the microsats their magnetically locked orbits
should offer a reasonably easy display. The problems of a tracking program
of this type mostly should revolve around processor, disk access and
display speed. So, write the programs to run on 386 33 MHz machines or
better. And of course, don't forget to include all the other nifty display
formats we've become accustomed to with other tracking programs. Even
though it might be nice to watch the sats on this type of display we would
all still want mercator (cylindrical or whatever displays). When viewing an
orbit it might be nice to include the ability to show squint angles
graphically as Instant track does, on all map formats. And one nice display
that I think only PCTRACK uses is an observer centered AZ EL display
showing the location and paths of any satellites currently passing over an
observer location.

Another wish, how about not limiting the program to Earth orbits. It would
be nice to have the entire solar system available so that probes like
Galileo, Ulysses etc. Could be plotted. And of course, don't forget the
Moon. Someday we may go back there. It would be nice to be able to track
objects in flight to and from the Moon as well as track objects in orbit
about the Moon itself. And if you do incorporate all these additional
possible orbits don't cut the earth orbital models out of action when
processing them. If a vehicle was on it's way to Jupiter, it would be
nice to know if it was visible from various tracking stations around the
earth as well as in sight of possible new satellites like TDRSs that were
responsible for relaying back data from those probes.

                    OTHER PROGRAMS LIKE ELEMENT MANAGER

What, advertising other folks wares. Well, this element addiction is a
pretty rare disease and so, there isn't much money to be made and
moreover, these other programs deserve a look see.

Element Master (Yep MASTER not MANAGER) by Sherman Spahr WB0PCM.

     Element Master was offered to AMSAT for distribution and may soon be
     available from them. It lets you create a selection file of
     satellites. Then later, you can run Element Master against an Element
     file and it will use your selection file to create a subset of the
     master file.

EDSAT by Frank Hentschel.

     Hmmm, it's been a VERY long time since I checked into Compuserve, but
     Frank is a religious hanger outer in the Astronomy forum. Just type
     GO ASTROF at any prompt and you'll get there. In either Library 3 or 7
     you'll find EDSAT. It will be listed with it's latest version number
     in the filename (ie: EDSAT21.ZIP) or something like that. EDSAT lets
     you edit existing elements. When you're finished you can correct the
     Checksums automatically. You can also check and fix Checksums in files
     you don't edit.

                        SATELLITE TRACKING PROGRAMS
                                for the IBM

----------------------
QuikTrak 4.xx
by Bob McGuire (N4HY)
----------------------

      QuikTrak is an excellent satellite tracking program. If you are into
      text displays I think it's the best. QuikTrak will keep track of up
      to 100 satellites in it's database. It will accept either 2-Line or
      AMSAT format element sets for updating via it's utility program
      QK.EXE.

      QuikTrak has both a graphic output and text modes. The graphic
      screens are very colorful in EGA and a nice feature of the program is
      that Bob supplies a CGA mode for older computer users. QuikTrak's
      nicer features are its ability to track more than one satellite
      simultaneously. In either the Text or Graphic modes you can follow
      the activities of up to 14 satellites. Each satellite is displayed on
      the map screen and on the text screens their current position, and
      lots of other useful information is provided. Another nice feature
      for Amateur Radio operators is the covisibility feature. If you wish
      to talk to someone via an Amateur satellite that bird must be visible
      to both stations.

      QuikTrak version 5.xx is rumored (heard it on Amateur radio nets and
      on some computer BBS echos) to be released soon. Take this with a
      grain of salt. Bob is an extremely busy guy. Having QT 4 is like
      holding a bit of history so, don't hesitate in ordering it if you
      need this type of program. It works well and reliably. I've used the
      program over 2 years and never discovered any buggy behavior. A new
      version will be adding something rather than correcting any problems
      since version 4 is bug free.

--------------------------
Instant Track Version 1.0
by Franklin Antonio
--------------------------

      Instant Track isn't quite up to the standards of QuikTrak in the text
      modes. Frankly it isn't close. But it more than makes up for it in
      it's graphic capabilities.

      Instant Track will display the current position of a satellite on a
      typical world map display. It will also show a globe display and plot
      the current position. A third output screen displays the orbital
      "shape" in relation to the planet and, if the bird has directional
      antennas, show the current pointing angle of those antennas. Finally,
      IT will show the satellite against a background of stars.

      The nice thing about IT is it's speed. You can change from one sat to
      the next in a flash. Only the Globe display suffers. This is because
      the display is created fresh for each new orbital position of the
      satellite. Unlike the world map that is static, the globe is very
      dynamic changing every few minutes to keep the selected satellite
      centered on the screen.

      IT has a built in updating feature that will use either AMSAT or 2-Line
      element sets.

      There are lots of other nifty features too numerous to mention.

      I know there is an update of IT in the works but this version is
      excellent and has no bugs so don't hesitate to buy hoping to find
      that update released. I've seen a beta version at some hamfests.
      Don't worry Franklin, that user wasn't advertising the fact, I just
      noticed some stuff related to attitude regarding microsats and the
      derived values screens and decided it must be something in the works.

Both QuikTrak and Instant Track are available from AMSAT NA.

AMSAT - NA Headquarters
850 Sligo Avenue, Suite 600
Silver Spring, MD  20910-4703

[phone] - 9 am to 5 pm Eastern Time

----------------------------------
GrafTrak II and Silicon Ephemeris
by Silicon Solutions, Inc.
P.O. Box 742546
Houston, Texas 77274
[phone]
----------------------------------

      This is a commercial product. It costs a bundle but the company will
      (or used to anyway) give a price break to a licensed amateur radio
      operator.

      In my opinion it is the best of the bunch if you want to graphically
      check out the activities of a satellite.

      Graf Trak will allow you to keep up to 16 satellites in a database.
      However, you can have as many of these database files online as you
      wish. At first Graf Trak seems a bit intimidating. You have to issue
      LOTS of commands at the DOS prompt to get the program up and running.
      However, in the long run this makes the program easier, not harder,
      to use. GT also allows for something they call command files. Instead
      of issuing lots of tedious commands at the DOS prompt you can call up
      GT with just one switch pointing to a command file. It may seem like
      an unnecessary feature, however GT has SO many options it's possible
      to run out of space on the DOS line entering various parameters (DOS
      line limited to 128 characters).

      GT is FAST. VERY FAST. When I bring up GT to look at amateur radio
      satellites, I have the program start with a particular satellite,
      plot a ground track for the next orbit. The program loads and starts
      displaying in under 7 seconds. GT has an easy user interface once
      you're inside the program. Hitting the page up key moves the program
      back in time one orbit. The down key moves it forward one orbit.
      Hitting the down arrow key moves the satellite forward in it's orbit
      until it rises over the designated observation point (you may have up
      to 16 observer locations in each Sat database). You can set the clock
      inside GT (no it doesn't effect the DOS clock) and display a
      satellite's position at any time future or past. You can set a jump
      interval. Make the program jump forward a minute, hour, day, week,
      etc. at the touch of a key. And GT recomputes all these changes in a
      few seconds. This is definitely my favorite graphic program.

      GT comes with something called Silicon Ephemeris. This is a separate
      program and performs the text functions of GT. There are some nice
      features available here but, I prefer QuikTrak generally for Text
      modes.

      GT comes with an updating program that will use either AMSAT or
      2-Line format files. Although it's only possible to keep track of 16
      satellites in a file, you can keep track of virtually an unlimited
      number of satellites by creating many such data files. The updating
      program can be run out of a batch file and update all satellite data
      files without user intervention.

----------------------
TRAKSAT Version 2.75
by Paul E. Traufler
111 Emerald Drive
Harvest, AL 35749
[phone]
----------------------

      This is one of the best shareware satellite tracking programs. It is
      pretty fast and has nice displays. However, it's not quite up to the
      capabilities or general slickness of the programs mentioned above.

      It should be mentioned that TrakSat (TS) has some nice features.

      It can simultaneously graphically and textually track multiple
      satellites in a manner similar to QuikTrak (QT). However, it does
      supply more information on the screen during this operation. QT will
      list information on each satellite on the screen as it is replotted.
      TS has a continual display of information on each plotted satellite.
      QT will track more satellites simultaneously than TS and has a full
      screen map making continuous display impractical. QT has more
      information available on its tabular multisat displays.

      TS can plot satellites on a star background. This feature is also
      available in Instant Track, however, TS does this job much better. In
      the realtime mode, TS will plot stars and identify them. It
      identifies the cardinal direction of the view presented. It plots the
      satellite as a moving object across this field. In the Delta time
      mode (a window of time where objects are analyzed) TS plots the
      satellite against the star field and marks the position of the
      satellite against that background by printing time ticks on the
      screen when that satellite occupied that location. This is a handy
      feature for the novice visual observer.

      TS will analyze an entire element file or a subset of that file for
      rise times over a particular observer location.

      TS will plot the satellite against a "flat" map of the world or
      against a sphere of the earth. On the spherical plot the display
      centers directly over the observer location and plots the satellite
      in space above the earth. In delta time mode this feature can produce
      interesting and informative displays of the size and shape of a
      satellite's orbit.

      I have a feeling that someday this program will evolve into a really
      nice piece of work. Possibly the best. The author is continually
      offering updates with improvements in performance and features.

note: Review Version of TrakSat found on TS Kelso's BBS (directory 0). I've
re-posted it on the Astro Comm-Post in Denver, Colorado (see credits).

--------------------------
PcTrack Version 2.1
by THOMAS C. JOHNSON
9920 S. PALMER RD.
NEW CARLISLE, OHIO 45344
--------------------------

      I like this one but, since it doesn't use AMSAT or 2-Line element
      sets and doesn't provide an updating feature to get the elements into
      it's proprietary satellite database, I find it useless. I AM NOT
      GOING TO MANUALLY ENTER ORBITAL ELEMENTS EVER AGAIN!!!.

note: Review version 2.1 available from Astro Comm-Post (see credits).

-----------------------
Mr. Orbit Version 3.0
by Stephen Wood
PO Box 592175
Orlando, FL  32859-2175
-----------------------

      This program is now freeware. It only looks for visual satellites but
      there is a text screen that displays current information for any of
      the satellites in it's database. If you like to look at visual passes
      of satellites this program is a MUST!!

note: Review version 3.0 available from Astro Comm-Post (see credits).


                                THANKS FOLKS

I would like to pass along my thanks to all those folks who make satellite
tracking so easy and enjoyable and who have contributed so much to the
evolution of tracking. Here just are a few.

Sherm Spahr (WB0PCM) - Sherm is the author of "Element Master". It was due
to his fine program that I decided to make a stab at "Element Manager".

Tom Clark (W3IWI) - Tom has been involved in this satellite tracking
business for a while now. His tracking program was my first exposure to
this interesting hobby. Long before I had a need to know, I was interested
in tracking just because it was so much fun to know where the birds were at
any given time. Tom's program was the first program I ever used. And it has
been the inspiration for lots of other folks too.

Bob McGuire (N4HY) - Bob wrote QuikTrak but he also has been deeply
involved in AMSAT's efforts to put satellites into service. Thanks for all
your efforts Bob.

TS Kelso - TS has been literally invaluable to the satellite watcher's
community. Without his BBS we'd all be up a creek regarding satellite
elements. Oh, I know we could all write to NASA and request reams of
information about all the birds we are interested in but it makes life so
much easier having one person get all the data and make it available. I
realize there are other folks providing element sets but, I would wager
that 90 percent of all element sets have passed through the Celestial RCP/M
BBS as one stage in their journey. Hopefully TS will find this program
useful himself. It would be small compensation for all the work he has done
in the satellite watching/tracking field. Thanks TS.

Frank Hentschel - Frank is a regular on the Astronomy Forum of CIS (or at
least he used to be, I haven't been by there in years). Frank did a lot of
work on W3IWI's program and was my first "real" satellite tracking program.
Since then Frank has offered an Element set editor and a few more tracking
programs. Thanks Frank.


SUPPORT AMSAT

I know that at the beginning of this DOC file I mentioned that this program
is free. Well it is, but if you would like to make a contribution to AMSAT
in compensation for using this program that would be "nice". AMSAT, like
all space agencies, is always short of cash. We could use a few million
bucks to get some geosync birds up and running and a few dollars from a few
million folks is about the only way we're going to make it. It's the little
contributions that help. This contribution should in no way make either
AMSAT or myself liable in anyway for the operations of this program and the
legal mumbo jumbo at the front of this document will still be in full
force.



                      APPENDIX A - THE TWO-LINE FORMAT

Actual Oscar 10 Element Set:

OSCAR 10
1 14129U 83 58  B 91312.44187316 -.00000072  00000-0  99998-4 0  7762
2 14129  25.9057 115.4097 6067273 291.5986  16.1497  2.05882356 35213

The KEY

name
1 CCCCCU YYNNN  Q TTTTT.TTTTTTTT  .DDDDDDDD  VVVVV-V  GGGGG-G 0  SSSZ
2 CCCCC III.IIII RRR.RRRR EEEEEEE PPP.PPPP AAA.AAAA MM.MMMMMMMMOOOOOZ

KEY:

name - the ASCII name designation of the satellite

Line 1
C-catalog Number
Y-Year of launch (not used in tracking)
N-Number of launch (not used in tracking)
Q-seQuence of payload deployment (not used in tracking)
T-epoch Time
D-Decay or Drag
V-second time deriVative of mean motion
G-draG term
0-(zero)ephemeris type
S-element Set number
Z-checksum

Line 2
I-Inclination
R-Right ascension of ascending node
E-Eccentricity
P-argument of Perigee
A-mean Anomaly
M-mean Motion
O-(letter "O" oh!)epoch Orbit number
Z-CheckSum

What they Mean
Line 1

C-the Catalog number
  Each time a satellite is launched NORAD assigns a number to that
satellite. Vanguard 1 is the earliest satellite I can currently find
element sets for (all earlier birds must have reentered by now). It was
launched on 3/17/58 and carries "00005" as a NORAD Catalog number.

Y-Year of launch
  In most 2-line sets now available the year the satellite was launched is
indicated by this two digit number. In the above Oscar 10 element set the
year 1983 is indicated. This number is for reference only and is not used
by tracking programs for predictions. Thus it may be omitted.

N-Number of launch
  This number indicates the number of the launch for that year. In Oscar
10's case, it was the 58th launch of the year. This number does not give
any indication as to when during the year the bird went up just it's
ranking among it's fellow launches for that year. This number is for
reference only and is not used by tracking programs for predictions. Thus it
may be omitted.

Q-seQuence of deployment.
  On many launches there are more than one payload. In the case of Oscar
10, that amateur radio satellite was the second item deployed from the
launcher. If you examine the element sets for the MicroSats (Catalog
numbers 20437 - 20442) you will see that each of the 6 satellites were
deployed from the same rocket booster (along with the primary mission
payload, SPOT 2). This number is for reference only and is not used by
tracking programs for predictions. Thus it may be omitted.

T-epoch Time
  The epoch time of an element set is the time when each of the various
parameters in that set were measured. The first two digits of the epoch
time are the year. In Oscar 10's case 1991. The next three digits are the
epoch day number. In Oscar 10's case the 312th day of the year 1991. The
decimal number that follows is the time during the 312th day (for Oscar 10)
that the element set was taken.  If this decimal were .5 it would be noon
UTC. If it were .75 it would be 18:00 UTC. In Oscar 10's Epoch time the
entire time breaks down to 11/09/91 at 10:36:17 UTC.Remember that all epoch
times are in UTC (GMT) time. As you will see, Element Manager translates
this number into an "English" format as above for easier comprehension.

D-Decay or Drag
  This number usually refers to atmospheric drag on a satellite. However,
at times satellites are strongly affected by the gravitational pull of
bodies other than the Earth (ie: Sun and Moon). While it seems unlikely,
drag can actually be a negative number thus indicating an increase in
orbital energy rather than a decrease. This happens when the Sun and Moon
combine to pull the satellite's apogee to a higher altitude. At least
that's the way I understand it. So, if you see a negative drag, it's ok.
However, this condition of negative drag is only valid for as long as the
gravitational situation warrants it. So, some folks like to zero out
negative drag factors for smoother orbital calculations (see note at the
end of this section).

V-second time deriVative of mean motion
  I'm unfamiliar with Astrodynamics and so can't explain this term. But,
some texts are listed at the end of this section that may lead you to
information that will help you to understand them. Regardless of my
inability to explain this term, I can say that some satellite prediction
programs will take advantage of it. Graf Trak II does so in one of it's
orbital prediction algorithms.

G-draG term
  As with the term above, I'm not fully familiar with this one either.
However, once again, Graf Trak will use it if it is present.

0-Ephemeris type
  Once again, as with the terms above, I don't know for sure what this term
refers to, so I just list it here for your information. Inside Element
Manager, this term is ignored.

Element Manager will copy files with these three terms intact. However, I
was afraid that editing the "conventional" drag and mean motion parameters
and leaving these without modification would introduce problems. So, if you
do edit an element set the values of terms are "zero"ed out.

S-element Set number
  Each time a satellite's orbit is determined and an element set created
the element set is assigned a number. In a 2-Line element set this number
is restricted to 1 through 999. So, if the satellite in question has had
more element sets generated than that, the figure rolls over to 000.

Z-Checksum
  The last number in each of the 2 lines of an element set is a checksum.
This number is calculated by assigning the following values to each
character on the line. A number carries it's own value, a minus (-) sign
carries a value of one (1), and letters, blanks and periods (decimal points
(.)) carry a value of zero (0).

  In the Oscar 10 element set above the checksum calculation would start
out like this for line one of the set. In column one is the number one (1).
So, so far the checksum is one (1). In column two is a blank space. That
carries a value of zero (0), so the checksum remains one (1). In column
three is the number one (1). Add this to the accumulated checksum so far
and the new checksum value is two (2). In column four is the number four
(4). Add four to the checksum value and the new value is six (6). If you
continue along through the entire line you will end up with a value of 172.
Only the last digit of this number is used. So the checksum of this line is
two "2". DO NOT ADD the last figure in column 69 as that is the actual
checksum. When programs verify Checksums they preform the above
calculations. If the value of the calculated checksum disagrees with the
very last (69th column) number then the element set fails the checksum test
and is considered a bad element set.

Line 2

I-Inclination
  The inclination of a satellite refers to the angle formed by the
orbit and the equator. The inclination must be a positive number of degrees
between 0 and 180. A zero angle of inclination indicates a satellite moving
from west to east directly over the equator. An inclination of 28 degrees
(most shuttle launches) would form an angle of 28 degrees between the
equator and the orbit of the satellite. Also, that satellite will travel
only as far north and south as +- 28 degrees latitude. On it's ascending
orbital crossing (moving from south to north) of the equator, the satellite
will be moving from southwest to northeast. An inclination of 90 degrees
would mean that the satellite is moving directly from south to north and
will cross directly over the north and south poles. Any satellite with an
inclination greater than 90 degrees is said to be in retrograde orbit. This
means the satellite is moving in a direction opposite the rotation of the
earth. A satellite with an inclination of 152 degrees will be moving from
southeast to northwest as it cross the equator from south to north. This is
opposite the rotation of the Earth. This satellite will move as far north
and south of the equator as 28 degrees latitude and be in an orbital
direction exactly opposite a satellite with an inclination of 28 degrees.

R-Right ascension of ascending node (RAAN or RA of Node)
  In order to fix the position of an orbit in space it is necessary to
refer to a coordinate system outside the earth coordinate system. Because
the Earth rotates latitude and longitude coordinates do not indicate an
absolute frame of reference. Therefore it was decided to use astronomical
conventions to fix orbits relative to the celestial sphere which is
delineated in degrees of Right Ascension and declination. Right ascension is
similar to longitude and Declination is similar to latitude. When an
element set is taken Right Ascension of the ascending Node is computed in
the following manner. As a satellite moves about the center of the earth it
crosses the equator twice. It is either in ascending node, moving from
south to north or descending node moving from north to south. The RAAN is
taken from the point at which the orbit crosses the equator moving from
south to north. If you were to stand at the center of the planet and look
directly at the location where the satellite crossed the equator you would
be pointing to the ascending node. To give this line a value the angle is
measured between this line and 0 degrees right ascension (RA). Again
standing at the center of the earth 0 degrees RA will always point to the
same location on the celestial sphere. I know this is a lousy explanation
of RAAN but it gives the idea. If you are familiar with RA/DEC in astronomy
you've probably figured out what I'm trying to say. Otherwise, refer to the
references at the bottom of this section for pointers to more knowledgeable
folks who can explain this properly.

E-Eccentricity
  All orbits are eccentric. That is, they are not perfectly circular but
are ellipses. Eccentricity denotes just how elliptical the orbit is. Oh, boy,
here we go again. Hypothetically an eccentricity of zero (0) would denote a
perfectly circular orbit. An eccentricity of .9 indicates an orbit of an
elongated ellipse. This orbit would pass relatively close to the earth on
perigee (closest point of the orbit to the earth. And it would reach an
apogee (farthest point of the orbit to earth) at a much greater distance.
In the case of Oscar 10 above, the eccentricity is ".6067273". This is a
very elliptical orbit. A satellite in this type of orbit spends little time
near the earth and much of it's time around the apogee of it's orbit.
Satellites travel faster at perigee, slower at apogee. It's a good orbit
for amateur radio work as it places the satellite in a slow moving orbit
high over the earth thus offering a large area of communications coverage
without the need to have fancy antenna tracking systems to follow it's
movements.

P-Argument of Perigee
  Since "all" satellites are in elliptical orbits their orbits have a
Perigee and an Apogee (defined above). Satellites move faster at perigee
than apogee and so to accurately calculate their orbits, this information
is necessary. The Argument of perigee is the angle as measured from the
center of the Earth between the ascending node and the perigee along the
plane of the orbit (inclination). If the Argument of perigee is zero (0)
then the lowest point of the orbit of that satellite would be at the same
location as the point where it crossed the equator in it's ascending node.
If the argument of perigee is 180 then the lowest point of the orbit would
be on the equator on the opposite side of the earth from the ascending
node.

A-Mean Anomaly (MA)
  The mean anomaly fixes the position of the satellite in the orbit as
described above. So far we have only talked about the shape and location of
the orbit of the satellite. We haven't placed the satellite along that path
and given it an exact location. That's what Mean Anomaly does. Mean Anomaly
is measured from the point of perigee. In the Argument of perigee example
above it was stated that an Arg of Perigee of zero would place perigee at
the same location as the Ascending node. If in this case the MA were also
zero then the satellite's position as of the taking of the element set
would also located directly over the equator at the ascending node. If the
Arg of Perigee was 0 degrees and the MA was 180 degrees then the
satellite's position would have been on the other side of the earth just
over the equator as it was headed from north to south.

M-Mean Motion (MM)
  At last an easy one. The mean motion of a satellite is simply the number
of orbits the satellite makes in one solar day (regular day, common day, 24
hours, 1440 minutes, 86400 seconds etc.). This number also generally
indicates the orbit altitude. For your enlightenment, Element Manager
computes the Perigee and Apogee altitudes above the surface of the earth in
kilometers. If you wish to convert these figures to miles divide by 1.609
(the number of kilometers in a mile).

O-Epoch Orbit Number
  Another easy one. Theoretically, this number equals the number of orbits
the satellite has completed since it's launch. However, once again, there
is a slight problem here. The 2-line format only allows for a maximum of
99,999 orbits to be counted before this figure has to roll over. In the
case of many old satellites, this number is inaccurate as the object has
orbited more than 100,000 times. Also some satellites have incorrect epoch
orbit numbers. Oscar 10 is just such a case. However, this number is
provided more for reference purposes than orbital calculation. And so, its
accuracy or lack thereof doesn't affect the accuracy of a prediction.

Z-CheckSum
  As with line one, this number is provided to check the accuracy of the
element set. It's calculation is described above.

NOTE: Perhaps you've noticed the inordinate hedging of bets I've placed
throughout the above descriptions. I would have loved to steal Franklin
Antonio's descriptions from his Instant Track DOC file but, couldn't bring
myself to it. So, I read it and then tried to bring it to this document in
my own words. I think I made a good stab at it but, his explanations were
ever so much clearer. But I did want to try and give Element Manager's
users some idea of just what they were playing around with. If you are
really interested in this stuff, then check out the following:

IT.DOC - The doc file for Instant Track. Antonio describes these parameters
in concise terms easily understandable to all.

"The Satellite Experimenter's Handbook" by Martin Davidoff. Available from
the Amateur Radio Relay League, 225 Main St, Newington, Connecticut 06111
and probably most stores that sell amateur radio gear.

If you want to learn something about orbital mechanics the Handbook above
is a good start and also for a reasonable price you can get:

"Fundamentals of Astrodynamics" by Roger Bate, Donald Mueller, and Jerry
White. Publisher: Dover Publications, NYC, NY Copyright 1971.


       APPENDIX B - REPAIRING BADLY FORMATTED NASA 2-LINE INPUT FILE

In reading over the messages on TS Kelso's board I realized that folks were
looking for a more robust 2-line file format checking program. Because I
always get my elements from Kelso's board, I was a bit lazy with versions 1
through 1.2 of Element Manager's format checking and correction features.
The program  would only look at the first line of a file for TS's
"- Current Two-Line Element Sets #xxx -" header line. I've transmitted many
element sets via packet radio and received them from many and varied
sources. Most of them could not have been handled by Element Manager's
previous versions. So, to cover "most" eventualities ...

NEW and IMPROVED

Element Manager can actually fix a bad or missing "English" satellite name.
In order to accomplish this you must have a file named SATNAME.DAT in the
default directory. This file takes the format of a standard Satellite
Select File:

14129:OSCAR 10
14781:UoSat 2
19216:AO-13
18129:RS-10/11
20437:UO-14
20438:UO-15

Whenever problems with the "English" satellite name are detected this file
is consulted to see if there is a valid name for the catalog number of the
set Element Manager is having problems with. As new satellites are launched
it's up to you to update SATNAME.DAT with appropriate data so Element
Manager can recover from any problems of this nature. The program will
still write out properly formatted 2-line element sets even if the problem
set isn't listed in the SATNAME.DAT file.

The error messages "No SatName Chk Input" and "Bad SatName" are substituted
for the satellite name as described below. Because "No SatName Chk Input"
and "Bad SatName" are obviously not correct satellite names, and because
they may creep into files occasionally, Element Manager will check
SATNAME.DAT for matching catalog numbers anytime it sees these satellite
"names". In this way it can correct these erroneous names if at a later
date you have added correct names to the SATNAME.DAT file.

Element Manager examines the second and third lines of the input file to
see if it is in fact the first line of a NASA 2-line formatted element set.
It accomplishes this by performing several checks. First Element Manager
looks for a "1 " (that's a 1 followed by a blank space) in columns one and
two. Next the program verifies that the character in column 7 is an integer
between 0 and 9. Third it checks for an upper case "U" in column 8. Next it
checks the length of the line to make sure it's 69 characters long. Finally
Element Manager verifies the positions of all decimal points in lines 2 and
3. While it may be unlikely, it's possible a 2-line file may retain the
ability to pass the first several checks and still be improperly formatted.
The decimal position test reduces the possibility of considering a bad line
as OK. But, it should be noted that it's still possible to pass all the
above tests and be improperly formatted. If these conditions are met then
Element Manager will consider that the file is in proper NASA 2-Line format
and load the file.

If any of these conditions are not met then Element Manager creates a
window containing the first three lines of the input file. Any trailing
spaces that might mislead length checks are striped from the three lines.
This time the case of the "U" is ignored. The program then performs the
same checks as above.

In addition, line 3 has some additional checks performed on it. The first 2
columns must contain a "2 " (that's a 2 followed by a blank space). The
characters that appear in columns 3 through 7 of line 3 (the catalog
number) must match the characters in the same position of line 2. The
length of line 3 must be 69 characters.

A check of line 1 is made to see if there is an English Satellite name.
This field may contain anything but blank spaces. A length check is made
and if the line's length is equal to or greater than 69 characters then the
program either changes the field name to "Bad SatName" or substitutes the
name of the corresponding catalog number in the SATNAME.DAT file. If you
see "Bad SatName" in almost always means that there was a set of 2-line
elements in the file with NO English satellite name and the file
SATNAME.DAT was either not present or didn't contain a matching catalog
number and the 2-line set's lines 1 and 2 immediately followed line two of
the preceding set. If the field is a blank line then, the program either
changes the blank name field to "No SatName Chk Input" to alert you to the
missing name or substitutes the name of the corresponding catalog number in
the SATNAME.DAT file. I forced these two corrections because the actual
2-line set that follows this warning is intact, carries an identifier you
can use to track down the error (catalog number), and is still usable by
many satellite programs. The only problem this may cause, some updating
programs use the English name as the identifier of an element set. In this
case, any set with the "No SatName..." or "Bad SatName" name would be
skipped in the updating procedure even though the actual element set for
that NORAD catalog number satellite is intact. Programs that use catalog
numbers to identify satellite elements for updating will ignore this
mismatch of names and write the new element sets to the satellite data file
of the program.

If the file passes these tests then the program will write out those
three lines to the new file (FIXED.TLE). All ALPHA characters are changed
to upper case in line 1. I'm not sure if this upper case, lower case
business is worth getting excited about. Probably, it isn't however, in the
event it becomes important to some program, uppercase will undoubtedly be
the preferred format (I hope).

If the format of an element set is bad the offending line will be written
to FAILED.TXT. Also, any lines in the file that are not part of a 2-line
set will be written to this file. To see how this works run this DOC file
into the program with the command:

ELEMAN /Ieleman.doc

When the file finishes loading exit from the program and compare FAILED.TXT
to this file. Seeing how Element Manager handles the examples below should
give you a pretty good idea of the power of this feature.

Whether or not the tests pass or fail Element Manager moves the window
down one line in the file. It then repeats those tests. In this manner it
is possible to detect all element sets and write them to a new file. The
only problem that may occur is if a NASA 2-Line set is somehow improperly
formatted. Below are some examples of bad formatting that Element Manager
can recover from and improper formatting that Element Manager cannot
recover from. Each example is discussed below. The beginning and end of
each element set file is denoted by the dashed line.


Example 1: perfectly formatted file (no corrections would be made)
---------------------------------------------------------------------
OSCAR 10
1 14129U 83 58  B 91312.44187316 -.00000072  00000-0  99998-4 0  7762
2 14129  25.9057 115.4097 6067273 291.5986  16.1497  2.05882356 35213
UoSat 2
1 14781U 84 21  B 91323.56626498  .00003271  00000-0  58134-3 0  1304
2 14781  97.8784   2.6201 0012732  37.5725 322.6366 14.67751126412231
---------------------------------------------------------------------


Example 2: improperly formatted file decimal positions incorrect for
OSCAR 10 (corrections will be made)
---------------------------------------------------------------------
OSCAR 10
1 14129U 83 58  B  91312.44187316 -.00000072 00000-0  99998-4 0  7762
2 14129   25.9057 115.4097 6067273 291.5986  16.1497 2.05882356 35213
UoSat 2
1 14781U 84 21  B 91323.56626498  .00003271  00000-0  58134-3 0  1304
2 14781  97.8784   2.6201 0012732  37.5725 322.6366 14.67751126412231
---------------------------------------------------------------------


Example 3: improperly formatted file (however, no corrections would be made)
---------------------------------------------------------------------
OSCAR 10
1 14129U 83 58  B 91312.44187316 -.00000072  00000-0  99998-4 0  7762
2 14129  25.9057 115.4097 6067273 291.5986  16.1497  2.05882356 35213

UoSat 2
1 14781U 84 21  B 91323.56626498  .00003271  00000-0  58134-3 0  1304
2 14781  97.8784   2.6201 0012732  37.5725 322.6366 14.67751126412231
RS-10/11
1 18129U          91325.41201369  .00000175  00000-0  18085-3 0 10188
2 18129  82.9248 302.6686 0013110 106.2990 253.9609 13.72233914221150
AO-13
1 19216U 88051  B 91310.60757627 -.00000072  00000-0  00000 0 0 02874
2 19216 056.7146 062.2382 7235702 269.3641 015.2670 02.09704227026046
---------------------------------------------------------------------


Example 4: improperly formatted file (corrections would be made)
---------------------------------------------------------------------
These header lines should not be contained in a "pure" element
file however, here they are anyway.

OSCAR 10
1 14129U 83 58  B 91312.44187316 -.00000072  00000-0  99998-4 0  7762
2 14129  25.9057 115.4097 6067273 291.5986  16.1497  2.05882356 35213
UoSat 2
1 14781U 84 21  B 91323.56626498  .00003271  00000-0  58134-3 0  1304
2 14781  97.8784   2.6201 0012732  37.5725 322.6366 14.67751126412231
RS-10/11
1 18129U          91325.41201369  .00000175  00000-0  18085-3 0 10188
2 18129  82.9248 302.6686 0013110 106.2990 253.9609 13.72233914221150
AO-13
1 19216U 88051  B 91310.60757627 -.00000072  00000-0  00000 0 0 02874
2 19216 056.7146 062.2382 7235702 269.3641 015.2670 02.09704227026046
---------------------------------------------------------------------


Example 5: improperly formatted file (corrections would be made)
---------------------------------------------------------------------
These header lines should not be contained in a "pure" element
file however, here they are anyway.

OSCAR 10
1 14129U 83 58  B 91312.44187316 -.00000072  00000-0  99998-4 0  7762
2 14129  25.9057 115.4097 6067273 291.5986  16.1497  2.05882356 35213
UoSat 2
1 14781U 84 21  B 91323.56626498  .00003271  00000-0  58134-3 0  1304
2 14781  97.8784   2.6201 0012732  37.5725 322.6366 14.67751126412231

Here's a comment in the middle of the file.

RS-10/11
1 18129U          91325.41201369  .00000175  00000-0  18085-3 0 10188
2 18129  82.9248 302.6686 0013110 106.2990 253.9609 13.72233914221150
AO-13
1 19216U 88051  B 91310.60757627 -.00000072  00000-0  00000 0 0 02874
2 19216 056.7146 062.2382 7235702 269.3641 015.2670 02.09704227026046

Here is a comment at the end of the file.
---------------------------------------------------------------------


Example 6: improperly formatted file (corrections would be made but... )
---------------------------------------------------------------------
OSCAR 10
1 14129U 83 58  B 91312.44187316 -.00000072  00000-0  99998-4 0  7762
2 14129  25.9057 115.4097 6067273 291.5986  16.1497  2.05882356 35213
UoSat 2

1 14781U 84 21  B 91323.56626498  .00003271  00000-0  58134-3 0  1304
2 14781  97.8784   2.6201 0012732  37.5725 322.6366 14.67751126412231
RS-10/11
1 18129U          91325.41201369  .00000175  00000-0  18085-3 0 10188
2 18129  82.9248 302.6686 0013110 106.2990 253.9609 13.72233914221150
AO-13
1 19216U 88051  B 91310.60757627 -.00000072  00000-0  00000 0 0 02874
2 19216 056.7146 062.2382 7235702 269.3641 015.2670 02.09704227026046
---------------------------------------------------------------------


Example 7: improperly formatted file (corrections would be made but... )
---------------------------------------------------------------------
OSCAR 10
1 14129U 83 58  B 91312.44187316 -.00000072  00000-0  99998-4 0  7762
2 14129  25.9057 115.4097 6067273 291.5986  16.1497  2.05882356 35213
1 14781U 84 21  B 91323.56626498  .00003271  00000-0  58134-3 0  1304
2 14781  97.8784   2.6201 0012732  37.5725 322.6366 14.67751126412231
RS-10/11
1 18129U          91325.41201369  .00000175  00000-0  18085-3 0 10188
2 18129  82.9248 302.6686 0013110 106.2990 253.9609 13.72233914221150
AO-13
1 19216U 88051  B 91310.60757627 -.00000072  00000-0  00000 0 0 02874
2 19216 056.7146 062.2382 7235702 269.3641 015.2670 02.09704227026046
---------------------------------------------------------------------


Some explanations

Example 1: Nothing wrong with this file. It would load normally.

Example 2: Because the decimal positions in the Oscar 10 element set are in
the incorrect position, this element set will fail and not be written to a
new file. UoSat 2 will be recognized as a correct element set and output to
a new file.

Example 3: Element Manager will not fix a file in which it finds that the
actual second and third lines of the file are properly formatted. The error
shown here (a blank line after the first element set) will be detected and
the program will reject the file for input. I considered having the program
go right on to a formatting correction procedure, however, thought better
of it. You might have listed the wrong filename and this gives you a chance
to recover without generating a FIXED.TLE file. If you do have a 2-Line
file that fails loading for this reason, check the file out and be sure
it's the one you wish corrected. If it is, just add a blank line to the top
of the file. That will cause Element Manager to go on to fix it.

Example 4: The most common error most folks are likely to find in 2-line
files is extraneous text at the beginning of a file. Using it's check
procedure, Element Manager will strip off the header information. It
doesn't matter how long this preamble goes on, Element Manager will keep
moving it's window down through the file until it finds an appropriate line
matching the specs for a 2-line element set. It then starts writing a new
file.

Example 5: If you collect your elements via Packet radio, they may be
spread over several packet messages. If you open your capture file prior to
reading these messages and close after the last message, Element Manager
will be able to read through the file picking out element sets. As long as
an element set contains 2 properly formatted sequential lines (Line 2:First
of Nasa 2-line, Line 3: Second of Nasa 2-Line), the program will output a
properly formatted file without all the additional material of message
headers, 73 tag lines etc.

Example 6: Here's an error that Element Manager may not completely recover
from. Because three lines of the 2-line set for UoSat 2 have been
separated, Element Manager will check the SATNAME.DAT file to see if there
is a matching catalog number for the bad set. If it fails to find a
matching catalog number then it will write out a corrected output file
substituting the "No SatName Chk Input" satellite name. In this case the
resulting file would look like this:

---------------------------------------------------------------------
OSCAR 10
1 14129U 83 58  B 91312.44187316 -.00000072  00000-0  99998-4 0  7762
2 14129  25.9057 115.4097 6067273 291.5986  16.1497  2.05882356 35213
No SatName Chk Input
1 14781U 84 21  B 91323.56626498  .00003271  00000-0  58134-3 0  1304
2 14781  97.8784   2.6201 0012732  37.5725 322.6366 14.67751126412231
RS-10/11
1 18129U          91325.41201369  .00000175  00000-0  18085-3 0 10188
2 18129  82.9248 302.6686 0013110 106.2990 253.9609 13.72233914221150
AO-13
1 19216U 88051  B 91310.60757627 -.00000072  00000-0  00000 0 0 02874
2 19216 056.7146 062.2382 7235702 269.3641 015.2670 02.09704227026046
---------------------------------------------------------------------


Example 7: In this case the English Satellite Name for UoSat 2 (cat #
14781) is missing. While processing this element set, Element Manager
thinks the last line of OSCAR 10's element set is the satellite name for
UoSat 2. Because this line is => 69 characters in length the program checks
SATNAME.DAT for a matching catalog number. If one is not found then Element
Manager will substitute "Bad SatName" for the English satellite name. The
resulting output will look like this.

---------------------------------------------------------------------
OSCAR 10
1 14129U 83 58  B 91312.44187316 -.00000072  00000-0  99998-4 0  7762
2 14129  25.9057 115.4097 6067273 291.5986  16.1497  2.05882356 35213
Bad SatName
1 14781U 84 21  B 91323.56626498  .00003271  00000-0  58134-3 0  1304
2 14781  97.8784   2.6201 0012732  37.5725 322.6366 14.67751126412231
RS-10/11
1 18129U          91325.41201369  .00000175  00000-0  18085-3 0 10188
2 18129  82.9248 302.6686 0013110 106.2990 253.9609 13.72233914221150
AO-13
1 19216U 88051  B 91310.60757627 -.00000072  00000-0  00000 0 0 02874
2 19216 056.7146 062.2382 7235702 269.3641 015.2670 02.09704227026046
---------------------------------------------------------------------

Notice that only the element set for UoSat 2 (14781) is corrupted (no
English Sat Name) in the above two examples with the remaining element sets
properly found and copied. In this case, the resultant file may be usable
by many programs.

What does it all boil down to? As long as individual element sets are
properly formatted it doesn't matter what precedes or follows them in a
file, they will be picked out and written to a new file. Any time there is
an error in the last two lines of an individual element set, the
program will skip that element set and continue outputting all the
remaining element sets that pass all the checks. If there is an error in
the English Name line (line 1) then Element Manager will substitute an
either an error message or new satellite name for the Sat name and write
out the element set as long as the next two lines of that set properly pass
all the tests described above. There can be lots of text interspersed with
the element sets. It will all be removed and only the elements will be
output to FIXED.TLE

I've used the word correction several times in the above descriptions. It
should be stressed that any element set that fails the checks listed above
is NOT corrected. Rather, the output file will be correct in that it
contains no element set that fails these tests.

For an interesting test of Element Manager's ability to extract 2-Line
element sets, just invoke the program with the following DOS command:

ELEMAN /Ieleman.doc /Otest /P

This commands Element Manager to load this DOC file as it's satellite input
file, output a new file named test.xxx where xxx will be the epoch day of
the most recent element set in the DOC file, and the /P forces the whole
thing to happen automatically. The program loads, tries to load ELEMAN.DOC,
discovers it's badly formatted, fixes these problems by extracting only the
properly formatted element sets within the file, writes these element sets
to FIXED.TLE, automatically changes the input filename to FIXED.TLE, and
processes that file checking for the most recent epochday of the element
sets contained within. It then outputs a file named TEST.xxx. There are
lots of duplicates in this file so you can use it to check the duplicate
checking features at a later time.


                           APPENDIX C - CREDITS

QuickBasic Version 4.5 - Copyright Microsoft

Leapyear and Epochday Algorithms derived from:

         W3IWI.BAS
         AMSAT ORBITAL PREDICTION PROGRAM
         6388 GUILFORD ROAD
         CLARKSVILLE, MD  21029
         COPYRIGHT 1980 BY DR. Thomas A. Clark

Perigee/Apogee Calculation Algorithms derived from:

         "The Satellite Experimenter's Handbook" by Martin Davidoff.
         Available from the Amateur Radio Relay League, 225 Main St,
         Newington, Connecticut 06111

         "Fundamentals of Astrodynamics" by Roger Bate, Donald Mueller, and
         Jerry White. Publisher: Dover Publications, NYC, NY Copyright
         1971.

         W3IWI.BAS - AMSAT ORBITAL PREDICTION PROGRAM

Explanations of orbital elements derived from:

         "IT.DOC" from "Instant Track" by Franklin Antonio

         "The Satellite Experimenter's Handbook" by Martin Davidoff.

         "Fundamentals of Astrodynamics" by Roger Bate, Donald Mueller, and
         Jerry White. Publisher: Dover Publications, NYC, NY Copyright
         1971.

         "GrafTrak II and Silicon Ephemeris" - instruction manual by
         Silicon Solutions, Inc., P.O. Box 742546, Houston, Texas 77274,
         [phone]

SEMIVIS.SEL and VERYVIS.SEL created from QUICKSAT by:

         Mike McCants
         Celestial BBS
         [e-mail] Internet
         5105 Crestway Dr.
         Austin, TX 78731
         [phone].

Astro Comm-Post Bulletin Board (1.2+ Gig files)

         This is a multi-line BBS with two primary hunt numbers. If you
         call the first number the BBS will connect you with the first
         available modem. If you dial the second number you will be
         connected only to a modem with HST capabilities (baud rates to
         14400). There are a couple of lines with V.32 protocol on them
         but, as I don't have a modem with that capability I don't know the
         numbers. Call and read the system bulletins for info about those
         lines. You might get lucky and be connected with one of these
         modems on your first access. I imagine that they have their own
         hunt number to help you avoid the other protocol lines. MOST of
         this BBS is closed to visitors however, the Astronomy area is open
         to guest users for file downloads. This is the area where
         satellite programs will be posted.

         [phone] (1200-2400)
         [phone] (greater than 2400 baud HST)


                           APPENDIX D - REVISIONS

For versions 1.0 through 1.8, I've only posted Element Manager on TS
Kelso's BBS. You may post the program anywhere you wish. This exclusive
posting of new versions may change at some time in the future.

1.0    Initial release

1.1    Added offset to correct for time differences between system clock
       and UTC. Offset can be entered at command line for auto processing.
       Within the program the configuration file will set the offset to the
       value you entered at the configuration editor screen.

       Added "English" time display to Element editor.

       Added QuikTrak format (English) entry capability for epoch day.

1.2    Corrected Element display on Selector/Editor screen. Bugs previously
       allowed a right arrow movement to move to a nonexistent element set
       if blank entries were located on the final display screen.

       When on the first element set of the last screen, if you entered the
       editor/viewer and moved to a previous element set the program did
       not change back one page when returning the Selector screen.
       Fixed.

       Added the Est. Age display to the editor screen.

       Added the Perigee and Apogee altitudes to the Element Editor screen.

       Fixed Config screen to properly reflect current configuration.

       Fixed screen formatting of the epoch year/day on the Statistics
       screen.

       Parameters in Config file for MM and INC wouldn't carry into
       program. Fixed.

       Increased the maximum number of Element Sets to 545.

1.3    Improved the file repair procedures. Most badly formatted element
       files will now be processed to extract element sets ONLY from the
       input file and written to the FIXED.TLE file.

       Severe bug in Duplicate checker squashed. When I originally wrote
       the dup checking routines, I only tested it with files containing
       lots of elements but only one duplicate. The program found this one
       just fine. However, if more than one element had duplicates or if
       one element set had more than one duplicate problems ensued. I'm
       pretty sure this problem is cured now. I spent quite a bit of time
       devising interesting element files with lots of duplicate element
       sets with varying dates and the same date and mixed duplicate
       problems. The program is now catching each and every duplicate and
       saving only the most recent element set for each dup. Non-dups are
       passing through just fine too. I discovered this problem while
       writing APPENDIX B in this DOC file where I suggest the use of that
       function. I did and boy did it fail miserably.

1.4    Changed the ages displayed in LogFile reports generated from Age
       Analysis display to reflect fractions of a day.

       Added Reference Times to Edit Elements screen.

       Added Element Set Ages to Edit Elements screen.

       Added Orbital period to Edit Elements screen.

       Added fractions of seconds to "English" time display on Edit
       Elements screen.

       Added Line Printer routines to print out data displayed in the Edit
       Element Screen. No graphic characters are used in this mode so the
       program should work on most printers.

       Added capability to input fractions of seconds in the "English"
       format editing of the Epoch day on the Edit Elements screen.

       Changed the validation check on inclination entry to require
       inclination not less than 0 not greater than 180 degrees.

       Added Satellite Name repair capabilities to the correct input file
       routines.

       Added routine to detect and report any badly formatted element sets
       when initially checking input file. Previously, the program only
       looked for blank lines. Now most of the checking procedures employed
       in repairing badly formatted element files are used to detect bad
       sets. If these sets are found, the program will still load the file,
       as long as no blank lines are found, however, an alert is now posted
       on the screen indicating bad sets were found and any sets that fail
       the tests are listed in the LogFile.

       Increased Maximum element sets to 1000.

       Added selective directory scanning. You can now enter "*.xxx" at any
       File Utilities Menu file prompt and be presented with a listing of
       all files with "xxx" as a file extension. All DOS wildcard functions
       will work ie: "?" or "*" (not just xxx).

1.5    Filenames were not showing up in the displays within the program
       properly. Thought this was fixed in 1.4 but ...

       Fixed bug in negative time offsets AND added fractional offset
       capability. Those folks in 1/2 hour time zones can now properly
       calculate age of element sets. Actually, any fractional hour may be
       entered so if you keep some really offbeat time in your computer,
       you can enter a strange offset and it will correctly figure UTC time
       (ie: -11.39).

       When correcting element set files Element Manager now writes out any
       lines that fail tests to the file FAILED.TXT. This file should
       contain any text not related to element sets and any badly formatted
       2-line element sets.

       Added sort routines. Element Manager will now sort on the English
       Satellite Name, Epochday of element set, Drag, Inclination, Arg of
       Perigee, Mean Anomaly, Mean Motion, Catalog Number, Epoch Orbit and
       Element Set number. In addition, you may restore the original file.

       Added find routine to the Selector/Editor screen. You can now search
       the input file for a particular English satellite name and catalog
       number.

       Changed the way Element Manager paints screens and added more color
       capability. Because of these additional color options you'll need to
       create a new configuration file EVEN if you run the program in B&W.
       If you don't you'll get an error message indicating input past end
       of file. Just erase any ELEMAN.CFG file and start the program. You
       can then create a new CFG file by going to the VIEW/EDIT
       configuration screen.

1.6    A horrifying bug crept into version 1.5 that really messed up the
       display while autoprocessing files. It's fixed.

       Bug in Selector/Editor screen involving element files that exactly
       filled screens fixed. When there were 39,78 etc. element sets in
       file the program would get lost and not identify the end of the
       file.

       But in output format fixed. If you had a CFG file set to 2-Line
       format and tried starting the program with the /A switch it wouldn't
       override the CFG. Now it does.

       Element Manager will now accept a Satellite Name field as long as 40
       characters. This to accomodate N2L files. Because this added lots of
       blank spaces to the name field, I've changed the output writing
       routines to strip any trailing blank spaces from that field. This
       will result in generally smaller file sizes.

       Minor cosmetic fixes, and a change to the Select Criteria option
       made. Instead of having to move to a third submenu to set MM/INC
       parameters those functions have been moved "up" to the Select
       Criteria menu.

       Bug that prevented new elements to be added at the Selector/Editor
       screen in versions 1.4 and 1.5 discovered and squashed.

       A very slight speed increase of around 15 percent implemented in the
       Sorting functions.

       When using the fix checksum and check for duplicates options,
       Element Manager no longer creates files if all checksums are OK or
       there are no duplicates.

       I'm confused!! Is the plus sign "+" assigned a value of zero "0" or
       two "2" for checksum purposes. Well, up until now it's been zero.
       But there is talk about accepting a "new" convention. Element
       Manager will default to assigning the plus sign a value of zero "0".
       If this turns out to be wrong relax. just start the program with the
       /Z command line switch and the plus sign will be assigned a value of
       two "2". Once the confusion in my grey cells dies down I'll make
       sure that the "correct" value becomes the default. NOTICE: /Z used
       to be the startup switch for bypassing the configuration file.
       That's been changed to /X.

1.7    Changes to the Search function in the Selector/Editor screen. If
       you've searched for a satellite previously, that name becomes a
       default for any subsequent searches. If you want to research the
       file for that sat/cat number just hit return.

       Added a cursor pointer/selector to the Main, Select Criteria and
       File Utilities menus.

       Added ability to specify a name for the file created within the
       element sorting section.

       Oops, I fixed up the check of the checksum by adding the /Z switch,
       however, those fixes weren't incorporated in the fix checksums part
       of the program. That's corrected.

       Added a stripping routine for plus signs. After the strip a new
       checksum is calculated.

       Some internal restructuring.

1.8    Found and corrected a bug introduced in version 1.6 that disabled
       the cursor control in the edit elements screen.

       Added a simple file viewer.

                                   -end-