This program is a beta version. While most of the obvious bugs have been fixed, there still may be some present. If you come across any bugs, please forward them to BEK Developers at:
CompuServe 75366,2557
BEK Developers
PO Box 47114
St. Petersburg, FL 33743-7114
Include enough information to allow bugs to be duplicated (ie what commands were used and what happened).
OrbiTrack should not be used for any precise or critical calculations. While the program should be accurate enough for general use, there are no guarantees on the accuracy of any results produced by OrbiTrack.
Getting Started
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OrbiTrack will run on any Macintosh computer. OrbiTrackFPU has been optomized to use the Floating Point processor Unit (FPU). It will run on any Macintosh with a FPU (Mac II, SE/030, etc.). OrbiTrackFPU will crash, however, on a Macintosh without the FPU.
To begin using the program, you should also have station and element data files. These data files should be located with this documentation file. If not, you may create a station record for your own location and download elements from several BBSs.
Load Data
To quickly begin using OrbiTrack, start the application and load in the station and satellite element data files. These are text files and are loaded by selecting the "Load Data." command located under the File menu and selecting the desired data file. Once the station and element data have been loaded, the commands under the option menu will then be enabled and can be executed.
Note: On some Macintosh computers such as a MacPlus, loading satellite data may be rather slow. If there are alot of satellites in the satellite element file, the loading process may take a while. If you are only interested in certain satellites, such as those in low orbit, you may want to abort the loading process (click in the window close box or type a command period) and set up the load filter.
Under the Pref menu, select the Ele Load Filter. If you are interested in low orbit satellites, set up the filter so that it will only load satellites with mean motion greater than 14.5 or so. Mean motion is the number of orbits a satellite makes in a day. A satellite in a low orbit makes more orbits per day. As a result, low orbiting satellites have a large mean motion. The largest you can expect the mean motion to get to is around 16. By then, the orbit is so low it won't be long until it re-enters.
Setting Default Station
You might now want to select the default station to be used with the program. The default station is normally chosen to be your own station. Click in the Pref menu and select the Set Default station menu command and select your station. This will become the default station for the program and can be used to select the proper time zone for certain options such as the Real-Time map. If your station is not contained in the list of available stations, you may pick a station reasonably close to you or enter your
station into the data storage. To add a new station, see the Edit Station section.
Options
There are 11 options available to run. They are:
Look
Visual satellite passes only from selected stations.
Track
All satellite passes from selected stations.
Position
Location of the satellite on the Earth.
Map
Plotting the satellite ground track on an Earth map.
Real-Time Map
Shows the current position of selected satellites on an Earth map.
Equator Crossing
Time and location of equator crossings.
Plane Crossing
Time when the plane of a satellite will cross a ground station.
Sat-to-Sat
Distances and velocities between 2 satellites.
Star Plot
Allows satellite passes to be plotted against the stars.
Satellite Search
Looks through loaded satellites to determine which satellite was seen.
Sunrise/Sunset
Sunrise and Sunset times for selected stations.
Program Details
File Menu
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Deleting Data
This allows the user to delete selected data bases used by OrbiTrack. You can delete Element, Station, Time Zone, and Star data.
Load Data
To load data from text files, you can use the "Load Data." command. The Load Data command can be used for any data files using the Satellite Data Specification. Currently, the data file types supported are:
SATDAT Satellite Data
STNDAT Station Data
STARDAT Star Data
STARTNASA2L NASA 2 Line Data
While the satellite and station data are used in most of the options, displaying satellite passes against a star display is the only option that requires the star data file.
Load NASA2L
NASA 2 line orbital elements that have no header information must use the Load NASA2L command. Below is an example.
The first line of the file must begin with the satellite name. If the file contains a STARTNASA2L and ends with a ENDNASA2L, the Load Data command should then be used.
Write Data
This command allows the user to write out ASCII text files of satellite and station data already loaded.
Edit Menu
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Edit Data
You can edit Element, Orbit, Station, and Time Zone data by using the Edit Data command.
Element Edit
Element Edit allows the user to enter new satellite elements, edit, sort, move, or delete the element data.
Orbit Edit
This is an experimental function. It allows the user to generate elements for a user defined orbit.
Station Edit
Station Edit allows the user to enter new stations, or adjust values for current stations, such as latitude, longitude, or time zones. The user can also move or delete station data records.
To add a station, click in the New button and enter the requested data. To enter the time zone information for your station, decide if you have one or two time zones. If you have Daylight Savings time you will have two time zones, otherwise you only have one time zone.
If you've selected one time zone, enter the description (ie EST, CST, etc.) and the offset from Greenwich Mean Time. For EST the offset is -5 hours and CST is -6 hours.
If you've selected two time zones, you need to enter the descriptions and time offsets as above, except for each of the two time zones. In addition, you need to enter when the time zone changes. If the default data is not correct for your station, for each time zone you need to enter the start and stop date (which should be only 7 days apart), the time the time zone will change, and the Day-of-Week it changes. When operating, the program will change to the given time zone when the given conditions are met.
The program looks for the Day-of-Week that is between the start and stop dates and then checks to see if the time is after the change time. If so, the time zone and offset are changed.
Time Zone Edit
Normally, when station data is loaded, the available time zones are also loaded. The time zones are used through out the program to allow the time data to be displayed in the selected time zone and to allow time zone changes if desired. At times though, the user may wish to add their own time zone. Time Zone Edit will allow the user to add, change, or delete the current available time zones.
Pref Menu
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The Pref menu is used to control the various operating conditions of the program. Below are descriptions of the available commands:
AM/PM Mode
When enabled, this allows times to be displayed using AM and PM instead of in 24 hour format.
Use Checksum
This allows the checksums on loaded data to be verified.
Suppress Formfeeds
This allows the user to suppress Formfeeds from being written into the option text output files.
Use Deg Symbol
When enabled, the degree symbol (°) is use in any outputs instead of the word "Deg". This is currently only used when writing element lists or copying element list to the clipboard. When sending elements to non-Macintosh computers, this should be disabled since the computer may not understand the character.
Orbit Model
There is several orbital models available for use. These are public domain models generated by the US Air Force. Although for the most part, the models appear to be accurate enough for normal usage, there could still be some error in the models as implemented in the program. Therefore, this program is not for use in any critical situation. When necessary, the results should be checked against other programs for cross checking. The available models are:
SGP
SGP4
SGP4/SDP4
SGP8
SGP8/SDP8
The different models have different benefits such as increased accuracys, but may take longer to execute. The SDP4 and SDP8 are "Deep Space" models and are only for high altitude satellites. There may be some problem using these models with the Look and Track options and in a few other cases where the time is backed up to determine the beginning, middle, or end of a pass. SGP, SGP4, or SGP8 are the recommended models except when you really need additional accuracys of the Deep Space models.
Units
This allows the user to select the desired units for displaying calculated data. The available units are:
km - kilometers
sm - statute miles
nm - nautical miles
Az/El Mode
This allows the user to display the Azimuth and Elevation in different ways. Normal mode just displays the data rounded to a degree. Easy mode causes the Elevation to be rounded to the nearest 10 degree and the Azimuth is described by N for North or NNE for North-northeast. The user can select either method or both.
Default Station
Using this the user can select the default station to be used by the program. This allows a particular station's time zones to be used when there is no other obvious choice. Examples of this would be when running most of the options except for Look, Track, and Satellite search. The default station and its time zone are chosen in the Parameter dialog box by selecting "Local Time Zone".
Data Base
There are some options available that allow the user to alter the element and station data base. When the program is started up for the first time, it defaults to putting the data in the Preferences folder located in the System folder. The location of the data can be altered using the following commands:
New Ele
Creates a new element data base file. The program will then switch over to that file for all element data.
Save Ele As
Takes the current element data base and lets the user change the name and location of the data file. The old data file is unchanged and remains in its previous location.
Select Ele
Allows the user to select a preexisting element data base file.
New Stn
Creates a new station data base file. The program will then switch over to that file for all station data.
Save Stn As
Takes the current station data base and lets the user change the name and location of the data file. The old data file is unchanged and remains in its previous location.
Select Stn
Allows the user to select a preexisting station data base file.
Ele Load Filter
This filter is used by the program when loading element text files, using the Load Data and Load NASA2L commands. It allows control over the types of element data that is desired to be loaded. A typical use is to only allow satellites whose mean motion is greater than or equal to 14 to be loaded. This will prevent satellites in higher orbits, such as geostationary orbit, to be loaded. With fewer satellites, the satellite selection list used in the program will operate much faster. This is especially importa
nt on slower computers such as the Macintosh Classic.
Stn Load Filter
This filter operates in much the same way as the element load filter, except that it controls which stations are loaded.
Other
This dialog allows control over several different functions. They are:
Add LF's to CR's on Data Output
When enabled, linefeeds are added to carriage returns on text data produced by the various Options. This is primarily important when the data will be transferred to a non-Macintosh computer that expects carriage returns and linefeeds on each line.
Add LF's to CR's on List Output
This is similar to the command above except that it is for data generated using the Write Data command. Again, this is primarily important when the data will be transferred to a non-Macintosh computer that expects carriage returns and linefeeds on each line.
Voyager 1.0 or 1.2 Format
The Look and Track options can output Pass data in a format that the program Voyager can plot against a star pattern. The data can be read into Voyager as a data file and when enabled by Voyager, displays a series of boxes across the stars indicating the satellite's position during the pass. The formats between the different versions of Voyager have a minor difference and thus require OrbiTrack to know which version of Voyager the data is for.
Printer Font and Size
The user can select the font and size to be used when printing.
Files Space or Tab Delimited
Text data produced by the Options can be output with either spaces or tabs between the different fields. This allows easy input to other programs, such as spreadsheets and data base programs. The other programs can then plot the data or perform other specialized manipulation of the data.
Option Output File Creator
When generating output text files, the user can select what file Creator to give to the file. This will allow a user to be able to double-click an output text file and have your favorite word processor launch and load the file. Some file Creators for some common programs are shown below:
MSWD Micorsoft Word
MACA Claris MacWrite
Print Tab Spacing
This allows the user to select tab spacing when printing text files.
Common Details
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In the program, there are several dialogs that are common throughout. They are described below:
Select Satellite
This dialog allows the user to select one or more satellites from a list. In some modes, several buttons along the bottom of the dialog box are enabled. They allow all satellites to be selected and certain satellites, based on user provided parameters, to be displayed and selected.
Select Station
This dialog allows the user to select one or more stations from a list. In some modes, several buttons along the bottom of the dialog box are enabled. They allow all stations to be selected and certain stations, based on user provided parameters, to be displayed and selected.
Option Parameters
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This dialog is used to allow the user to select various values to be used when the particular Option is run. A description of the items in the dialog box is below. Depending on the option, some of these items may not be available.
Start Date/Time
This is when the calculations should begin.
Stop Date/Time
This is when the calculations should end.
Start Now
The current time and date is used for the start date/time.
Stop Offset X Day
This adds X Days to the start date/time and sets the stop date/time to the result.
Use Date Only
This causes the Start Now and Stop Offset commands to only affect the start and stop dates. The times are not affected.
Resolution or Step Size
Determines how precise a calculation is to be made. Usually, the finer the number, the longer the calculation time is required. However, if too long a time is entered, erroneous or skipped results may occur.
Max Range
The satellite must be within the given range to the station.
Min Ele
During a pass, the satellite must be at least this amount above the horizon. During Look, the satellite must also be illuminated above this elevation.
Horizon Ele
This is the horizon used by the program. This can not be greater than the minimum elevation.
Sun Angle
The sun must be below the horizon by this amount.
Auto Pass Start Locate
This allows the program to automatically calculate the beginning of a pass. If the program gets confused when a satellite pass begins, you may want to disable this function. If this is disabled, the program starts at the beginning time and steps through using the Resolution time.
Min Mean Motion
When the Auto Pass Start Location function is enabled, the mean motion of the satellite must also be greater than this value. For example, if a value of 1.1 is entered, this will cause the program to not use the auto start function for geostationary satellites.
Local Time Zone
Allows the program to use either the current station or the default station as set up under the Pref menu. The local time zone refers to the current station for options such as Look and Track. The default station is used for the other options where there is no station, such as in the Position option, or there are multiple stations used at the same time, such as in the Real-Time Map option. If this command is not available, the default station has probably not been set. You need to select the Set Default Sta
tion command under the Pref menu.
Select Time Zone
This command allows you to force a particular time zone to be used. A pop-up menu allows easy access to the time zones which are in the program's data base.
Output Sunrise/Sunset
This causes the the Sunrise and Sunset time to be displayed for each day a pass occurs. Erroneous results may occur at locations near the poles.
Schedule
This causes the program to sequence the satellite passes in chronological order. To do this, the program will go through the entire list of selected satellites first to determine which pass is first.
Star Plot
In Look and Track, this mode writes the RA and Decl of the satellite's position in the sky to a file. This file can then be used in the Star Plot option to display the satellite's pass against a star pattern.
Voyager Output
In Look and Track, this mode writes the RA and Decl of the satellite's position in the sky to a file. This file is in a format understood as a data file by the Voyager Star Plot program. The Voyager program has a much better display of the star patterns and is recommended for viewing plots of satellite passes against a star pattern.
Output Mode
Pass outputs in Look and Track may be in either Full, Summary, or Full/Summary modes. Full mode displays data on the satellite pass using resolution as the step size. Summary displays data on the beginning, mid point, and end of a satellite pass.
Day Format
This command allows the Start and Stop times to be displayed in two different ways. It can be displayed in either Month/Day/Year Hour:Minute mode or in Year Day mode.
Output Configuration
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This dialog allows the user to change the items displayed when an option is performed. The output items available vary in each option. Currently, the user can not change the order of the output items.
Settings
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There are two types of settings available to the user. One type is used for most options and the other is used for the Map option.
Normal Settings
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Output Header
Satellite and/or station data is displayed for all selected satellites and/or stations.
Suppress Headers
No satellite and/or station data is displayed.
Suppress No-pass Headers
Satellite and/or station data is displayed only for satellites and/or stations which have a pass. This is primarily used in Look and Track options.
Satellite Name
When satellite data is written, only output the satellite name.
Full Satellite Data
When satellite data is written, output the complete data for the satellite.
Station Name
When station data is written, only output the station name.
Full Station Data
When station data is written, output the complete data for the station.
Auto File Name
When an option is run, the file name used for output data is automatically calculated based on the option and the time and date.
Select File Name
The user may enter a particular file name to use.
Disable File Output
No data is written to disk.
Beep When Complete
This causes the computer to beep when calculations are complete.
Notify Before Deleting
This causes the computer to ask the user if a file should be deleted. This will normally only occur when the user has chosen Select File Name.
Map Settings
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Display Ticks
This enables tick marks to be displayed along the satellite's ground track.
Shadow Marks
This causes the ground track to become wider when the satellite will be in the Earth's shadow.
Tick Mark Every X Steps
This will cause a tick mark to be displayed every X number of steps on the ground track. The step size is set in the Option Parameter dialog box.
Tick Mark Every X Minutes
This will cause a tick mark to be displayed every X minutes along the ground track. This is rounded so that it is divisible by the step size. The step size is set in the Option Parameter dialog box.
Station Circle
The station circle may be based upon the height of the satellite at Apogee, Perigee, or midway between the two.
Beep When Complete
This causes the computer to beep when calculations are complete.
Element Filter
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This filter is used by the Satellite Select dialog and the Element Load Filter command.
Station Filter
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This filter is used by the Station Select dialog and the Station Load Filter command.
Options
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Look
This Option searches for visual passes for the selected satellites at the selected stations. This is normally run so that people on the ground can see a satellite pass overhead. Satellites can be quite bright so that they can be seen with the naked eye. The space shuttle has sometimes been as bright as the brightest star or planet and can be mistaken as an airplane.
For a pass to be "Found", the station must be in darkness and the satellite illuminated by the sun. Also, when illuminated, the satellite must be high enough so that a person on the ground can see it.
Track
Track is similar to the Look Option except that the station being in darkness and the satellite being in sun light is not required. Track is typically used for radio communications since that can occur day or night.
Position
Location of the satellite on the Earth.
Map
Plotting the satellite ground track on an Earth map.
Real-Time Map
Shows the current position of selected satellites on an Earth map.
Equator Crossing
Time and location of equator crossings.
Plane Crossing
Time when the plane of a satellite will cross a ground station.
Sat-to-Sat
Distances and velocities between 2 satellites.
Star Plot
Allows satellite passes to be plotted against the stars.
Satellite Search
Looks through loaded satellites to determine which satellite was seen.
