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1991-12-05
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PC-TRACK File Conversion Utility
Copyright (c) 1991 Thomas C. Johnson
=====================================
This conversion utility has been written at the request of many users who
wanted an easier way to update their satellite data file. It takes advantage
of the data made available by the Celestial BBS in Fairborn, Ohio and other
BBSs that carry NASA Two Line Orbital Elements. The Celestial BBS is
dedicated to satellite tracking needs and contains several files which have
updated keplerian element sets for a large number of satellites.
One of the main data files is called TLE.TXT. It contains data for over
100 satellites. It is also available in an archived form called TLE.ARC.
(See below for information about the Celestial BBS)
CONVERT will take the ASCII text in the file (format shown below), and
convert the data therein to the format required by PC-TRACK.
SYNTAX:
CONVERT [d:\path\srcfile] [d:\path\destobjfile]
or
CONVERT /H
Where:
srcfile is the source data filename.
destobjfile is the destination object filename.
Invoking CONVERT with no parameters will cause it to utilize the following
defaults:
srcfile = TLE.TXT
destobjfile = OBJECTS.DAT
Example:
To convert the TLE.TXT provided in the \PCTRACK directory to the
OBJECTS.DAT file in the \PCTRACK\DATA directory, you would use the
following syntax:
CONVERT * .\DATA\OBJECTS.DAT
(Assuming you were currently in the \PCTRACK directory)
=============================================================================
NOTE:
THE FOLLOWING INFORMATION WAS DOWNLOADED FROM THE CELESTIAL BBS
FOR YOUR CONVENIENCE.
==================
Format Description
==================
Data for each satellite will consist of three lines in the following format:
AAAAAAAAAAA
1 NNNNNU NNNNNAAA NNNNN.NNNNNNNN +.NNNNNNNN +NNNNN-N +NNNNN-N N NNNNN
2 NNNNN NNN.NNNN NNN.NNNN NNNNNNN NNN.NNNN NNN.NNNN NN.NNNNNNNNNNNNNN
Line 0 is a eleven-character name.
Lines 1 and 2 are the standard Two-Line Orbital Element Set Format identical
to that used by NASA and NORAD. The format description is:
Line 1
Column Description
01-01 Line Number of Element Data
03-07 Satellite Number
10-11 International Designator (Last two digits of launch year)
12-14 International Designator (Launch number of the year)
15-17 International Designator (Piece of launch)
19-20 Epoch Year (Last two digits of year)
21-32 Epoch (Julian Day and fractional portion of the day)
34-43 First Time Derivative of the Mean Motion
or Ballistic Coefficient (Depending of ephemeris type)
45-52 Second Time Derivative of Mean Motion (Blank if N/A)
54-61 BSTAR drag term if GP4 general perturbation theory was used.
Otherwise, radiation pressure coefficient.
63-63 Ephemeris type
65-68 Element number
69-69 Check Sum (Modulo 10)
(Letters, blanks, periods = 0; minus sign = 1; plus sign = 2)
Line 2
Column Description
01-01 Line Number of Element Data
03-07 Satellite Number
09-16 Inclination [Degrees]
18-25 Right Ascension of the Ascending Node [Degrees]
27-33 Eccentricity (decimal point assumed)
35-42 Argument of Perigee [Degrees]
44-51 Mean Anomaly [Degrees]
53-63 Mean Motion [Revs per day]
64-68 Revolution number at epoch [Revs]
69-69 Check Sum (Modulo 10)
All other columns are blank or fixed.
Example:
NOAA 6
1 11416U 86 50.28438588 0.00000140 67960-4 0 5293
2 11416 98.5105 69.3305 0012788 63.2828 296.9658 14.24899292346978
Note that the International Designator fields are frequently blank. All
epochs are UTC (Coordinated Universal Time).
=====================
Satellite Frequencies
=====================
Oftentimes, users request lists of the frequencies used by the satellites
contained in two-line element sets. While there are some lists online for
amateur radio and weather satellites and the space shuttle (use the WHATSFOR
option in the File Section and use "frequency" as a keyword to search on), it
would be impossible for me to keep up with a list of frequencies for any large
number of satellites. All satellites operate on a number of different
frequencies and many of them change frequencies on a regular basis. Which
frequencies you are interested in depends upon what you are trying to do. If
you cannot find the information you need here, ask a specific question (e.g.,
What frequency does NOAA 11 transmit APT data on?) in a message addressed to
ALL; that should get you started. I welcome the assistance of anyone willing
to provide frequency information on satellites with which they are familiar; I
will take whatever inputs I receive and compile them into a master listing.
==================
System Description
==================
The Celestial BBS is a public domain Bulletin Board System (BBS) designed to
facilitate communications between individuals with interests in the space
sciences (Astronomy, Astrodynamics, Astrophysics, Celestial Mechanics, and
Satellite Technology) and related computer applications. The BBS may be used
to pass information and ask questions on these and related subjects. The BBS
is intended to provide a Public Domain Software Exchange (PDSE) primarily for
applications relating to the space sciences, as well as general utilities.
All contributions are welcome!
The Celestial BBS receives calls at
(513) 427-0674.
The SYSOP is T.S. Kelso.
===============
Mailing Address
===============
The mailing address is:
Celestial BBS
2340 Raider Drive
Fairborn, OH 45324-2001