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- SATRAK.DOC PC Version 5.38 Page 1 of 4
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-
- SATRAK is a major modification of `USAT' to provide a program that is
- user friendly and will function for the rest of the 20th century and
- possibly into the early 21st century. This program is intended for use
- by all Amateur Radio Operators and others interested in the functions
- it performs in Non-Commercial applications.
-
- System Requirements: IBM PC, XT, AT, or compatible computer with 256 K
- of memory, a Color Graphics Adapter with either a color or monchrome
- monitor and any combination of drives. All SATRAK files must reside on
- the default drive in the default directory.
-
-
- Files required for SATRAK operation are:
- ---------------------------------------
- SATRAK.BAS - GW Basic Ver. 2.12 Source Code
- or
- SATRAK.EXE - Compiled Version
- and
- SATRAK.DAT - Database of Satellite Records Available
- SATRAK.GSD - Ground Station Data
- SATRAK.MAP - World Map for Realtime Tracking Screen
- SATRAK.DEF - User Default Definitions
- SATRAK.DOC - Program Description
-
-
- SATRAK - MAIN MENU OPTIONS :
- ============================
- (P) Orbital Prediction Listing
- (R) Realtime Tracking On High Resolution Sreeen
- (C) Change, Add, Delete Satellite Records
- (G) Change Ground Station Data
- (S) Set User Defaults: Blink, Delay And Tweak
- (N) Convert Day Of Year Number To Date And Time
- (D) Return To DOS
-
- Enter Selection (P,R,C,G,S,N,D)-->
- (will accept UPPER or lower case)
-
-
- This program is capable of making orbit predication lists output to the
- screen or printer for any satellite in the database for a user defined
- time period, time step and minimum elevation angle. On screen
- simulation of realtime tracking of satellites in orbit or table type
- listing starting with the selected satellite and up to seven (7)
- additional satellites for a maximum of eight (8) with current valid
- data in the database.
-
- If the listing is blinking on and off it could be visible from your
- Ground Station location depending on your minimum Elevation Angle
- required to clear local obstructions. On a color monitor in addition
- to blinking these listings will be in red. Data contained in the .DAT,
- .GSD and .DEF files can be altered from within the program.
-
-
- (continued on Page 2)
-
-
- SATRAK.DOC PC Version 5.38 Page 2 of 4
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-
- It provides you with a user friendly interface to the program and no
- longer depends on specialized internal time dependent data .
-
- The original version of `USAT' program does not explain how you can
- obtain or generate the sidereal time table matrix data yourself.
- SATRAK now generates the data required. Sometime after the year 2000
- this method may not be adequate. SATRAK has a method for tweaking this
- data if necessary as explained later in this document.
-
- SATRAK contains program sections by each of the following individuals.
- I have made some changes in the current wording and/or locations of
- these sections in the modified program.
-
- "USAT" program by Ing. H. F. Strasser - OE1HSI - Jan. 1985 which
- included the following programs by others.
-
- Satellite Tracking By R. D. Welch - W0SL - May 1983
- Orbital Prediction By Dr. Thomas A. Clark - W3IWI - May 1980
-
- In order for the user to be better informed about the information
- SATRAK uses I have provided screen displays of all the information
- currently in the Ground Station Data file, User Default Definition file
- and Satellite Database file. Changes or additions to any of these
- files can be made by selecting the proper options from the Main Menu.
-
-
- SATRAK.DAT - You will be required to keep the satellite data records on
- file current. This means the Epoch Year, Epoch Day and other data for
- each satellite must be from the current or preceding year. You can
- update this data using information from local packet bulletin boards or
- AMSAT nets held on various frequencies. The satellite listing will
- inform you which satellite records contain "CURRENT" or "OLD" Data.
- A maximum of eight (8) records with `CURRENT DATA' will be displayed
- on the Realtime Tracking Screen when that option is selected.
-
-
- SATRAK.GSD - Normally when you receive this program the data in the
- file will be for some other Amateur Radio Operators QTH so you will
- need to make changes in this file so that your station coordinates are
- taken into account when using the `realtime tracking' or `orbital
- predications' portions of the program. You need to furnish your Call,
- QTH, Latitude and Longitude to 3 decimal places, and height above sea
- level for your receiving antenna in Meters.
-
-
- SATRAK.DEF contains the User Default values for BLINK, DELAY, TWEAK and
- CAL variables. The Blink Delay for the Graphics Screen has a range of
- 10 to 10000 with a default value of 500. The Line Delay is for the
- Status Line of the Graphics Screen and has a range of 10 to 20000 with
- default value of 1000. These were made into variables the user can
- a change because of the large range of speeds available with computers
- past and present. Set BLINK for ~ 0.25 sec. and DELAY for ~ 1.0 sec.
-
-
- (continued on Page 3)
-
-
- SATRAK.DOC PC Version 5.38 Page 3 of 4
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-
- SATRAK.DEF (Tweak Cal. contiuned)
-
- The Tweak Calibration is for adjustment of the internally calulated
- sidereal time constant and can be either a plus or minus adjustment.
-
- It is to be used to compensate for descrepancies in actual location and
- time verus program predicted location and time.
-
- TWEAK is an expression where one is equal to a 24 hour day. Therefore
- when time is entered in seconds as a positive or negative number it
- becomes a decimal number of from 4 to 7 places to the right of the
- decimal point.
-
- Example: 0.0000583 for positive correction of 5 seconds or -0.0000583
- for a negative correction of 5 seconds. CAL is the conversion of TWEAK
- to a decimal value of Plus or Minus Minutes to keep you informed.
-
- Some Single Precision TWEAK Values For Time Are:
- ------------------------------------------------------
- 1 second = 0.0000116 30 seconds = 0.0003499
- 5 seconds = 0.0000583 60 seconds = 0.0006999
- 10 seconds = 0.0001166 300 seconds = 0.0034998
-
- The average sidereal time constant for the years 1981 through 2019 is
- 0.2760026. This nineteen year average value then represents a time
- span of 6 Hours, 37 Minutes and 26.6251 Seconds.
-
- The deviation above this value was 1 Minute and 57.8524 Seconds.
- The deviation below this value was 2 Minutes and 00.4234 Seconds.
-
- As mentioned earlier if you are experiencing some timing problems
- working the amatuer satellite some minor corrections can be made using
- TWEAK to pad the internal calculated values up or down. When you do
- this all satellite records must be current and in the same year. This
- is because the year used for this internal calculation will be from the
- satellite record selected.
-
- TWEAK IS NOT A TOY FUNCTION TO PLAY WITH !! IF YOU DO NOT NEED OR
- UNDERSTAND ITS FUNCTION LEAVE THE DEFAULT VALUE SET TO ZERO !!
-
- Unless you have precise methods to test and verify that the changes you
- make using TWEAK are improving your operations I recommend not using
- the function.
-
- SATRAK.MAP Contains the graphic information to draw a flat map of the
- world on your monitor in High Resolution Black And White Graphics Mode
- and must be keep in tack as received. It is used by the Realtime
- Tracking option.
-
- The above information explains how the files that SATRAK uses fit into
- the overall picture.
-
- The Orbitial Prediction section can output the data to screen or
-
- (continued on Page 4)
-
-
- SATRAK.DOC PC Version 5.38 Page 4 of 4
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-
- printer. You define the starting and stopping point for this function
- along with a step rate and minimum elevation angle for your particular
- antenna system.
-
- The program then prints out a set of parameter changes which are used
- for this current set of listings on the first sheet of paper followed
- by as many other sheets as required to list the occasions when the
- satellite is in view of your receiving antenna for the period
- requested. Ability to work an "in view" satellite will depend upon the
- combination of "Range" and "Height" variables matched against your
- station capabilities.
-
- The Realtime Tracking section will place a cross on the Map Screen for
- up to eight satellite's with `Current Data' in its database record.
- These location crosses will be updated approximatly every two seconds
- times the number of satellites being displayed. You may toggle between
- the Table listing and Map Screen using the <F9> function key. The
- program will display each satellites current location information on
- the bottom line of the display or you can request continuos listing of
- just one particular satellite using the <F10> function key. Enter the
- satellite name at the prompt or just <ENTER> to return to listing up to
- eight satellites.
-
- The Convert Day of Year Number To Date and Time section is a useful
- utility when you need to know what calendar date and time corresponds
- to the day of year number stored as each satellite's Epoch date. This
- section saves a lot of time and effort figuring that out for you.
-
- If you are going to use this program for show purposes only using just
- the realtime tracking section then you can tolerate the use of data
- classified as `CURRENT' even though it is one or almost two years old.
- You can even update your database with the data using internal
- calculated values from the Orbital Prediction Section since accuracy is
- not really all that important for that type of operation.
-
- For the serious user I suggest obtaining AMSAT data every sixty days or
- sooner. For satellites that average six or less orbits per day try 60
- day updates. For those that average seven to thirteen orbits per day
- try 45 day updates. Then for those that average over thirteen try 30
- day updates.
-
- The `USAT' program's database file `ELEMENTS.DAT' is not compatible with SATRAK's database file `SATRAK.DAT'.
-
- It has been a very interesting experience finding out how all the
- pieces should fit together and operate. Then formulate soulutions for
- fixing each fault. I admit to a lot of remodeling along the way to
- make the program look and feel as I felt it should have been from the
- start. The real point to make is that it did not work right when I
- received it and now it will work right for many years to come.
-
- 73's
- H.A.Jones, WB8AMI
-
- SATRAK.DOC / Rev. G / 01-16-1990 /
-