NOAA KLM User's GuideAppendix A.3 
Table A.31 contains an explanation of the code symbols used for all parts of the TBUS1 and TBUS2 Predict messages.
Symbol  Explanation 

TBUS1 (or TBUS2)  APT Bulletin originating in the United States: TBUS1 is North to South (descending) daylight orbit. TBUS2 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 A2). 
PART I  Equator crossing reference information follows:  
0  Code group indicator for first three groups 
N_{r}N_{r}N_{r}N_{r}  Number of reference orbit. (Note: Information in Parts II and III also are related to this reference orbit.) 
D_{r}D_{r}H_{r}H_{r}m_{r}m_{r}s_{r}s_{r}  Reference orbit equator crossing time (GMT), satellite northbound: D_{r}D_{r}  Day of Month H_{r}H_{r}  Hour m_{r}m_{r}  Minute s_{r}s_{r}  Second 
Note: In TBUS1, northbound equator crossing takes place on NIGHT side of orbit. In TBUS2, northbound equator crossing takes place on DAY side of orbit.  
Q_{r}  Octant satellite is entering after crossing equator on reference orbit (See Figure A.31). 
L_{o}L_{o}L_{o}L_{o}  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"). 
L_{o}L_{o}L_{o}L_{o}  Degrees and hundredths of degrees longitude between successive equator crossings. 
N_{4}N_{4}N_{4}N_{4}  Orbit number of fourth orbit following reference orbit. 
H_{4}H_{4}  Hour of northbound satellite equator crossing four orbits after reference orbit. 
m_{4}m_{4}  Minute 
s_{4}s_{4}  Second 
Q_{4}  Octant satellite is entering after crossing equator on fourth orbit after reference orbit. 
L_{o}L_{o}L_{o}L_{o}  Equator crossing longitude of fourth orbit after reference orbit. 
Above information is repeated for eighth (N_{8}N_{8}N_{8}N_{8}) and twelfth (N_{12}N_{12}N_{12}N_{12}) orbits following reference orbit.  
NIGHT PART II (TBUS1) or DAY PART II (TBUS2): Contains satellite altitude and subpoint coordinates at twominute intervals after time of equator crossing; satellite northbound.  
02  Indicator; satellite altitude and subpoint coordinates at two minutes after time of equator crossing. 
a_{02}a_{02}  Altitude, in hundreds and tens of kilometers, attwo minutes after equator crossing. Thousands figure understood; hence 1440 km is encoded as 44.) 
Q_{02}  Octant of globe at two minutes after equator crossing. 
L_{a}L_{a}l_{a}  Latitude of satellite subpoint in degrees and tenths of degrees at two minutes after equator crossing. 
L_{o}L_{o}L_{o}  Longitude of satellite subpoint in degrees and tenths of degrees at two minutes after equator crossing. 
Above information is repeated at twominute intervals over the NIGHT portion of the orbit north of the equator for TBUS1, and DAY portion of the orbit north of the equator for TBUS2.) 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 (TBUS1) or DAY PART III (TBUS2): Satellite altitude and subpoint coordinates at twominute 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. 
a_{02}a_{02}  Satellite altitude in hundreds and tens of kilometers at two minutes after equator crossing. 
Q_{02}  Octant of globe at two minutes after equator crossing. 
L_{a}L_{a}l_{a}  Latitude of satellite subpoint in degrees and tenths of degrees at two minutes after crossing. 
L_{o}L_{o}L_{o}  Longitude of satellite subpoint in degrees and tenths of degrees at two minutes after equator crossing. 
Above information is repeated at twominute intervals over the night portion of the orbit south of the equator for TBUS1, and sunlight portion of the orbit north of the equator for TBUS2.  
DAY PART II (TBUS2) NIGHT PART II (TBUS1): Satellite altitude and subpoint coordinates at twominute intervals after time of equator crossing follows.  
02  Information pertinent to 02 minutes after equator crossing follows. 
a_{02}a_{02}  Satellite altitude in hundreds and tens of kilometers at 02 minutes after equator crossing. 
Q_{02}  Octant of globe at 02 minutes after equator crossing. 
L_{a}L_{a}l_{a}  Latitude of satellite subpoint in degrees and tenths of degrees at 02 minutes after equator crossing. 
L_{o}L_{o}L_{o}  Longitude of satellite subpoint in degrees and tenths of degrees at 02 minutes after equator crossing. 
Above information is repeated at twominutes intervals over the sunlit portion of the orbit north of the equator for TBUS2, and night portion of the orbit north of the equator for TBUS1.  
DAY PART III (TBUS1) or NIGHT PART III (TBUS2): Satellite altitude and subpoint coordinates at twominute 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. 
a_{02}a_{02}  Satellite altitude in tens of kilometers at two minutes after equator crossings. 
Q_{02}  Octant of globe at two minutes after equator crossing. 
L_{a}L_{a}l_{a}  Latitude of satellite subpoint in degrees and tenths of degrees at two minutes after equator crossing. 
L_{o}L_{o}L_{o}  Longitude of satellite subpoint in degrees and tenths of degrees at two minutes after equator crossing. 
Above information is repeated at twominute intervals over the sunlit portion of the orbit south of
the equator for TBUS1 and night portion of the orbit south of the equator for TBUS2.
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.32. 
Part IV Code Symbols
In Table A.32, 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 Semimajor 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 CDA/M (m^{2}/kg), to eight decimal places. 
ZZZ  Daily solar flux value (10.7 cm) 10^{7} W/m^{2}. 
aaa  90day running mean of solar flux 10^{7} W/m^{2}. 
bbb  Planetary magnetic index (2x10^{5} gauss). 
cccc  Drag modulation coefficient, to four decimal places. 
dddddddddd  Radiation pressure coefficient (m^{2}/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) 
Previous Section  Top of Page  Next Section 