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- As a service to the satellite user community, the following description of the
- NORAD two-line orbital element set format is uploaded to sci.space.news and
- rec.radio.amateur.space on a monthly basis. The most current orbital elements
- from the NORAD two-line element sets are carried on the Celestial BBS, *(205)
- 409-9280*, and are updated several times weekly. Documentation and tracking
- software are also available on this system. The Celestial BBS may be accessed
- 24 hours/day at 300, 1200, 2400, 4800, or 9600 bps using 8 data bits, 1 stop
- bit, no parity. In addition, element sets (updated weekly) and some
- documentation and software are also available via anonymous ftp from
- archive.afit.af.mil (129.92.1.66) in the directory pub/space.
-
- ==============================================================================
-
- Data for each satellite consists of three lines in the following format:
-
- AAAAAAAAAAAAAAAAAAAAAA
- 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 twenty-two-character name (this change is being made to be
- consistent with the name length in the NORAD SATCAT).
-
- Lines 1 and 2 are the standard Two-Line Orbital Element Set Format identical
- to that used by NORAD and NASA. 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 on ephemeris type)
- 45-52 Second Time Derivative of Mean Motion (decimal point assumed;
- blank if N/A)
- 54-61 BSTAR drag term if GP4 general perturbation theory was used.
- Otherwise, radiation pressure coefficient. (Decimal point assumed)
- 63-63 Ephemeris type
- 65-68 Element number
- 69-69 Check Sum (Modulo 10)
- (Letters, blanks, periods, plus signs = 0; minus signs = 1)
-
- 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
-