NOAA KLM User's GuideAppendix A.3 |
Table A.3-1 contains an explanation of the code symbols used for all parts of the TBUS-1 and TBUS-2 Predict messages.
| Symbol | Explanation |
|---|---|
| TBUS-1 (or TBUS-2) | APT Bulletin originating in the United States: TBUS-1 is North to South (descending) daylight orbit. TBUS-2 is South to North (ascending) daylight orbit. |
| KWBC | Traffic entered at Washington, D.C. |
| APT PREDICT | Identifies message content. |
| MMDDSS | Message serial number MM - Month DD - Day of Month SS - Number of spacecraft to which predict applies (See Table A-2). |
| PART I - Equator crossing reference information follows: | |
| 0 | Code group indicator for first three groups |
| NrNrNrNr | Number of reference orbit. (Note: Information in Parts II and III also are related to this reference orbit.) |
| DrDrHrHrmrmrsrsr | Reference orbit equator crossing time (GMT), satellite northbound: DrDr - Day of Month HrHr - Hour mrmr - Minute srsr - Second |
| Note: In TBUS-1, northbound equator crossing takes place on NIGHT side of orbit. In TBUS-2, northbound equator crossing takes place on DAY side of orbit. | |
| Qr | Octant satellite is entering after crossing equator on reference orbit (See Figure A.3-1). |
| LoLoLoLo | Reference orbit equator crossing longitude in degrees and hundredths. |
| T | Indicator: nodal period follows (will always be shown as "T"). |
| mm | Nodal period, minutes |
| ss | Nodal period, seconds. (Note: Hundreds group will not be included. Example: 100 minutes 13 seconds will be coded as 0013.) |
| L | Indicator, nodal longitude increment follows (always shown as "L"). |
| LoLoLoLo | Degrees and hundredths of degrees longitude between successive equator crossings. |
| N4N4N4N4 | Orbit number of fourth orbit following reference orbit. |
| H4H4 | Hour of northbound satellite equator crossing four orbits after reference orbit. |
| m4m4 | Minute |
| s4s4 | Second |
| Q4 | Octant satellite is entering after crossing equator on fourth orbit after reference orbit. |
| LoLoLoLo | Equator crossing longitude of fourth orbit after reference orbit. |
| Above information is repeated for eighth (N8N8N8N8) and twelfth (N12N12N12N12) orbits following reference orbit. | |
| NIGHT PART II (TBUS-1) or DAY PART II (TBUS-2): Contains satellite altitude and subpoint coordinates at two-minute intervals after time of equator crossing; satellite northbound. | |
| 02 | Indicator; satellite altitude and subpoint coordinates at two minutes after time of equator crossing. |
| a02a02 | Altitude, in hundreds and tens of kilometers, attwo minutes after equator crossing. Thousands figure understood; hence 1440 km is encoded as 44.) |
| Q02 | Octant of globe at two minutes after equator crossing. |
| LaLala | Latitude of satellite subpoint in degrees and tenths of degrees at two minutes after equator crossing. |
| LoLoLo | Longitude of satellite subpoint in degrees and tenths of degrees at two minutes after equator crossing. |
| Above information is repeated at two-minute intervals over the NIGHT portion of the orbit north of the equator for TBUS-1, and DAY portion of the orbit north of the equator for TBUS-2.) Note: Should the time after ascending node become greater than 99, the hundreds will be assumed (example, minute 102 will be encoded as 02). | |
| NIGHT PART III (TBUS-1) or DAY PART III (TBUS-2): Satellite altitude and subpoint coordinates at two-minute intervals south of equator on the ascending side of the orbit. | |
| 02 | Indicator; satellite altitude and subpoint coordinates at two minutes after time of equator crossing follows. |
| a02a02 | Satellite altitude in hundreds and tens of kilometers at two minutes after equator crossing. |
| Q02 | Octant of globe at two minutes after equator crossing. |
| LaLala | Latitude of satellite subpoint in degrees and tenths of degrees at two minutes after crossing. |
| LoLoLo | Longitude of satellite subpoint in degrees and tenths of degrees at two minutes after equator crossing. |
| Above information is repeated at two-minute intervals over the night portion of the orbit south of the equator for TBUS-1, and sunlight portion of the orbit north of the equator for TBUS-2. | |
| DAY PART II (TBUS-2) NIGHT PART II (TBUS-1): Satellite altitude and subpoint coordinates at two-minute intervals after time of equator crossing follows. | |
| 02 | Information pertinent to 02 minutes after equator crossing follows. |
| a02a02 | Satellite altitude in hundreds and tens of kilometers at 02 minutes after equator crossing. |
| Q02 | Octant of globe at 02 minutes after equator crossing. |
| LaLala | Latitude of satellite subpoint in degrees and tenths of degrees at 02 minutes after equator crossing. |
| LoLoLo | Longitude of satellite subpoint in degrees and tenths of degrees at 02 minutes after equator crossing. |
| Above information is repeated at two-minutes intervals over the sunlit portion of the orbit north of the equator for TBUS-2, and night portion of the orbit north of the equator for TBUS-1. | |
| DAY PART III (TBUS-1) or NIGHT PART III (TBUS-2): Satellite altitude and subpoint coordinates at two-minute intervals south of the equator on the descending side of the orbit. | |
| 02 | Indicator: satellite altitude and subpoint coordinates at two minutes after time of equator crossing. |
| a02a02 | Satellite altitude in tens of kilometers at two minutes after equator crossings. |
| Q02 | Octant of globe at two minutes after equator crossing. |
| LaLala | Latitude of satellite subpoint in degrees and tenths of degrees at two minutes after equator crossing. |
| LoLoLo | Longitude of satellite subpoint in degrees and tenths of degrees at two minutes after equator crossing. |
| Above information is repeated at two-minute intervals over the sunlit portion of the orbit south of
the equator for TBUS-1 and night portion of the orbit south of the equator for TBUS-2.
Note: Should the time after ascending node become greater than 99, the hundreds will be assumed (example, minute 102 will be encoded as 02). |
|
| PART IV: Contains high precision orbital elements transmission frequencies, and remarks - See Table A.3-2. | |

Part IV Code Symbols
In Table A.3-2, the classical elements (Keplerian) from MMMMMMMM to RRRRRRRR are Brouwer mean (BM) elements expressed in the form of
Keplerian elements. The position and velocity components SSSSSSSSSS to XXXXXXXXX are instantaneous. The Greenwich Hour Angle is
apparent sidereal time.
| Symbol | Explanation |
|---|---|
| AAAAAAAAA | Spacecraft identification (International designator) |
| BBBBB | Orbit number at epoch. |
| CCCCCCCCCCCC | Time of the first ascending node, in days, from the beginning of the year, to nine decimal places. |
| DD | Epoch year |
| EE | Epoch month |
| FF | Epoch day |
| GG | Epoch hour |
| HH | Epoch minute |
| IIIII | Epoch second, to three decimal places |
| JJJJJJJ | Apparent Greenwich Hour Angle at Aries at epoch, to four decimal places. |
| KKKKKKKK | Anomalistic period (minutes), to four decimal places. |
| LLLLLLLL | Nodal period (minutes), to four decimal places. |
| MMMMMMMM | Brouwer Mean (BM) Eccentricity, eight decimal places. |
| NNNNNNNN | BM Argument of perigee (degrees), five decimal places. |
| OOOOOOOO | BM Right Ascension of the ascending node (degrees), five decimal places. |
| PPPPPPPP | BM Inclination (degrees), five decimal places. |
| QQQQQQQQ | BM Mean anomaly (degrees), five decimal places. |
| RRRRRRRR | BM Semi-major axis (km), three decimal places. |
| SSSSSSSSSS | Sign and epoch X position component (km), to four decimal places. |
| TTTTTTTTTT | Sign and epoch Y position component (km), to four decimal places. |
| UUUUUUUUUU | Sign and epoch Z position component (km), to four decimal places. |
| VVVVVVVVV | Sign and epoch X velocity (Xdot) component (km/sec), to six decimal places. |
| WWWWWWWWW | Sign and epoch Y velocity (Ydot) component (km/sec), to six decimal places. |
| XXXXXXXXX | Sign and epoch Z velocity (Zdot) component(km/sec), to six decimal places. |
| YYYYYYYYY | Ballistics coefficient CD-A/M (m2/kg), to eight decimal places. |
| ZZZ | Daily solar flux value (10.7 cm) 10-7 W/m2. |
| aaa | 90-day running mean of solar flux 10-7 W/m2. |
| bbb | Planetary magnetic index (2x10-5 gauss). |
| cccc | Drag modulation coefficient, to four decimal places. |
| dddddddddd | Radiation pressure coefficient (m2/kg), to ten decimal places. |
| eeeeeeeee | Sign and perigee motion (degrees/day), to five decimal places. |
| fffffffff | Sign and motion of Right Ascension of the ascending node (degrees/day), to five decimal places. |
| ggggggggg | Sign and rate of change of mean anomaly at epoch (degrees/day), to two decimal places. |
| hhhhhhhh | Equator crossing longitude of the epoch reference orbit measure as East longitude, to five decimal places. |
| iiiiii | Month, date and year (MMDDYY) of last TIP clock correction. |
| jjjjjj | Sign and clock error after last correction measured in seconds, to three decimal places. (see Note 1) |
| kkkkkk | Month, date and year (MMDDYY) of current clock error. |
| llllll | Sign and current clock error measured in seconds, to three decimal places. (see Note 1) |
| mmmmmm | Month, date and year (MMDDYY) of the measured clock error rate. |
| nnnnnn | Sign and clock error rate expressed as milliseconds/day. (see Note 1) |
| oooooo | Month, date and year (MMDDYY) of next TIP clock correction. (000000 if unknown.) |
| Notes: All signed values in Part IV are preceded by a "P" or "M" to denote a plus (+) or minus (-) value.
1. These will be set to 99999 if the value is unknown |
|
| APT TRANSMISSION FREQUENCY XXX.XX MHZ HRPT TRANSMISSION FREQUENCY XXXX.XX MHZ BEACON (DSB) TRANSMISSION FREQUENCY XXX.XX MHZ APT DAY X/X APT NIGHT X/X DCS CLK TIME YR/DA/TIM XXXX XXX XXXXX.XXX (ADDITIONAL PLAIN LANGUAGE REMARKS WHEN NEEDED) |
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