NOAA KLM User's Guide
APT Predict (TBUS) Bulletin Code
The TBUS is a national practice code form used by the United States to transmit information for predicting the path or locating the position of polar orbiting environmental satellites. It is transmitted daily, at about 1900Z, by KWBC Washington, DC, on the Global Telecommunications Service network.
The TBUS-1 code form is used to convey information about satellites that are descending in daylight (i.e., north to south direction of travel in daytime), while the TBUS-2 code form relates to satellites that are ascending in daylight (south to north). Figure A-1 shows a schematic of the information given in TBUS-1 and TBUS-2 bulletins.
This appendix contains the code forms for TBUS-1 and TBUS-2, a list of the satellite identifiers used in TBUS messages, an
explanation of code symbols, samples of an APT Predict (TBUS) bulletin and a Two Line Element message, and how they can be
|SS||Satellite (see Table A-2)|
|Q||Octant of Globe (see Figure A.3-2)|
|LoLo||Longitude (tens and units)|
|1o1o||Longitude (tenths and hundredths)|
|T||Group indicator (orbital period)|
|L||Group indicator (nodal period)|
|aa||Altitude in hundreds and tens of kilometers|
Table A-2 contains the numbers used in TBUS bulletins to identify the satellite.
|10 - 19||ITOS series satellites|
|20 - 29||SMS/GOES series satellites|
|40 - 49||NOAA-M through -N' satellites|
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