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- ║ Satellite Orbital Prediction Software ║
- ║ By John A. Magliacane ║
- ║ « KD2BD Software - Copyright 1994 » ║
- ╚═════════════════════════════════════════╝
-
-
- * INTRODUCTION *
- ----------------
- PREDICT is a satellite orbital prediction program written in 'C' for the
- MS-DOS operating system by John A. Magliacane, KD2BD in 1994. It was
- designed specifically to assist in Amateur Satellite communications, and
- contains features useful in making visual observations of larger satellites.
-
- PREDICT was originally designed to run on a 1 MHz Commodore 64 computer
- in 1992. As a result, the orbital tracking and prediction algorithms
- contained in PREDICT have been optimized for high speed operation. During
- its development, the program crossed over from the C64 environment to
- several multi-user Unix and SunOS platforms, and then finally over to
- MS-DOS. This version issued in 1994 is menu driven and supports a mouse.
-
-
- * CONDITIONS OF USE *
- ---------------------
- The files contained in this software package are the property of John A.
- Magliacane, copyright 1994. You are welcomed to share this software with
- others provided it is distributed in a complete and unmodified form and
- that no fee or other consideration is charged or accepted. You are granted
- the right to use this software for non-commercial purposes without further
- permission. Commercial use of PREDICT without the expressed written
- permission of the author is strictly forbidden. John A. Magliacane, the
- author of this software, shall not be liable in any way for any damages
- arising out of the proper or improper use of this software or its related
- files.
-
-
- * GETTING STARTED *
- -------------------
- The main program menu of PREDICT provides the following program options:
-
- [F1] : Predict Satellite Passes
- [F2] : Auto Update Keplerian Data Base
- [F3] : Keyboard Edit Of Data Base
- [F4] : Satellite Orbital Information
- [F5] : Ground Station Information
- [?] : Help!
- [ESC] : Exit Program
-
- The satellite ground station callsign and geographical location information
- may be entered using the [F5] editing utility. Ground station location
- should be entered in decimal degrees north latitude (south is entered as
- negative), and decimal degrees west longitude. Your altitude above ground
- should be entered in meters. The hour differential between your system
- clock and UTC should also be entered.
-
- All satellite programs require current Keplerian data for the satellites
- of interest to the ground station operator. PREDICT holds orbital data
- for 21 of your favorite satellites. Keplerian data is available from a
- variety of sources in several different formats. The most popular is the
-
-
- "NASA 2-line" format. This format is available through NASA and AMSAT
- information sources on packet radio, telephone BBSs, and the Internet.
- It contains the satellite name on a single line followed by two lines of
- orbital data. Redundancy is incorporated into this format through the use
- of a modulo 10 checksum digit on the end of each line:
-
- MIR
- 1 16609U 86017A 94111.21750077 .00004090 00000-0 58434-4 0 5749
- 2 16609 51.6453 111.7160 0015230 167.5089 192.6283 15.58719614467153
-
- PREDICT's "Auto Update" [F2] mode accepts orbital data in this form contained
- in an ASCII text file and verifies the data against the checksum digits to
- insure accuracy. It links object numbers between the 2-line element file
- and the predict.dat file when the "Auto Update" program option is chosen.
- This allows the user to label a satellite with a different name than what
- is indicated in the 2-line element file.
-
- When auto updating orbital data from a 2-line element source file, PREDICT
- rejects all extraneous ASCII text, mail headers, etc., that may come either
- before or after valid 2-line element data. In addition, it will only update
- from Keplerian data that has a reference epoch time equal to or greater than
- the data currently held in the predict.dat file.
-
- Keplerian orbital data may also be entered through the keyboard using the
- keyboard editing utility [F3]. In either case, the satellite program keeps
- the old Keplerian data file as a back-up (predict.old).
-
- Orbital data can be entered, changed, or edited manually using the [F3]
- program option. New satellites can be added to PREDICT's orbital data
- base by entering the new data into the program using the [F3] option.
- This can be done automatically if a NASA 2-line element file is available.
- Simply enter the satellite name and object name manually using the [F3]
- utility. Accept the old orbital data by pressing ENTER at each line, then
- run the "Auto Update" function [F2], and the orbital data for the new
- satellite will be added to PREDICT's data file.
-
- Once the program is loaded with Keplerian data and the ground station
- location, it is ready to run.
-
-
- * SATELLITE ORBITAL PREDICTION *
- --------------------------------
- The satellite orbital prediction mode begins by prompting the user for a
- satellite selection from a list of 21 satellite names:
-
-
- [A]: OSCAR-10 [H]: OSCAR-20 [O]: OSCAR-27
-
- [B]: OSCAR-11 [I]: RS10/RS11 [P]: MIR
-
- [C]: OSCAR-13 [J]: RS12/RS13 [Q]: UARS
-
- [D]: PACSAT [K]: RS14/AO21 [R]: NOAA-9
-
- [E]: DOVE [L]: OSCAR-22 [S]: NOAA-10
-
- [F]: WEBERSAT [M]: OSCAR-23 [T]: NOAA-11
-
- [G]: LUSAT [N]: ITAMSAT [U]: NOAA-12
-
-
-
-
- Selection can be either via the keyboard or by clicking the mouse on
- the satellite name displayed on the screen. The user is prompted for
- a starting date and time to begin the orbital prediction calculations.
-
- The starting time must be entered in UTC using the format:
-
- DDMonYR HH:MM:SS
-
- such as: 01May94 02:00:00
-
- The default starting date and time is the current date and time and may be
- accepted simply by pressing the [ENTER] key and not entering any time.
-
- If the satellite is in range at the time entered, PREDICT will move back
- in time to find the time of AOS, and start printing an orbital calendar
- starting at AOS. Tracking data is displayed one screen at a time. A typical
- satellite pass might look something like this:
-
- KD2BD's Orbit Calendar For RS14/AO21
- Date Time El Az Phase Lat Long Range Orbit
- -------------------------------------------------------------
- 01May94 02:01:08 0 172 110 10 70 3659 16311
- 01May94 02:02:58 7 169 114 16 69 2982 16311
- 01May94 02:04:47 16 165 119 22 69 2328 16311
- 01May94 02:06:33 28 158 123 28 68 1745 16311 +
- 01May94 02:08:10 45 140 127 34 68 1325 16311 +
- 01May94 02:09:29 56 103 130 38 67 1159 16311 +
- 01May94 02:10:31 54 64 133 42 67 1191 16311 +
- 01May94 02:11:36 42 39 135 45 66 1371 16311 +
- 01May94 02:12:58 29 26 139 50 65 1734 16311 +
- 01May94 02:14:35 17 18 143 55 64 2262 16311 +
- 01May94 02:16:20 8 14 147 61 62 2888 16311 +
- 01May94 02:18:08 1 12 151 67 58 3558 16311 +
- 01May94 02:18:36 0 11 153 68 57 3731 16311 +
-
- The information displayed is defined as follows:
-
- Date : Date in UTC
- Time : Hours, minutes, seconds UTC in 24 hour format
- El : Satellite elevation above the ground station horizon in degrees
- Az : Satellite azimuth heading (North = 0 degrees)
- Phase : Modulo 256 orbital counter. Perigee = 0, Apogee = 128
- Lat : Sub-satellite point latitude in degrees North
- Long : Sub-satellite point longitude in degrees West
- Range : Distance between the satellite and the ground station in kilometers
- Orbit : Orbit number. Number of perigees that have occurred since launch
-
- A '*' symbol at the end of the line indicates the satellite is in sunlight.
- A '+' symbol indicates it is in sunlight while the ground station is in
- twilight. Some larger satellites are visible under these conditions as
- reflected sunlight causes them to appear as "stars" moving across the sky.
- If the end of the line is blank, the satellite is not in sunlight.
-
- Each screen is concluded with the prompt:
-
- More? [y/n] >>
-
-
-
- Entering the letter 'n', hitting the ESCAPE key, or clicking the right
- mouse button ends the orbital prediction calculations, while entering a
- 'y', pressing the ENTER key, the space bar, or clicking the left mouse
- button causes the program to advance to the next screen of orbital
- predictions.
-
-
- * LOGGING SCREEN OUTPUT TO A FILE *
- -----------------------------------
- A screen logging feature is available in PREDICT and is activated by
- pressing CTRL-BACKSPACE while in the orbital prediction mode. Orbital
- predictions displayed on the screen can be logged to a file for future
- reference or printing using this feature. Once activated, the current
- screen and all subsequent orbital prediction screens are copied to a file
- named "satname.txt". Invalid filename characters are replaced with an
- underscore ('_') character.
-
- The file logging feature is de-activated by pressing CTRL-BACKSPACE once
- again, or by exiting the orbital prediction mode. If it is re-activated
- once again at a later time for the same satellite, the orbital data will be
- appended to the older data using the same file name. The file may be
- edited at a later time using the DOS text editor and printed on a printer.
-
-
- * CONTRIBUTIONS WELCOMED *
- ==========================
- A considerable amount of time and effort has gone into the development
- of PREDICT. If you find this software useful, a reasonable contribution
- would be appreciated. Not only would a contribution help compensate for the
- hard work and long hours that have gone into the development of this accurate
- and easy-to-use satellite orbital prediction program, but your financial
- support would also serve as encouragement for the author to pursue enhanced
- versions of PREDICT and other related software.
-
- Checks should be made payable in US funds to the author and sent to the
- following address:
-
- John A. Magliacane, KD2BD
- 1320 Willow Drive
- Sea Girt, New Jersey 08750-2315
-
- Comments and suggestions regarding PREDICT are also welcomed with your
- payment.
-
- Thank you!
-
- 73, de John, KD2BD