Novatel MiLLennium OM-20000040, User Manual, Page: 93 / 130

H NovAtel Format Logs
GPS/GLONASS Receiver User Manual Rev 1 93
H.1.4 GEPA/B EPHEMERIS INFORMATION
GLONASS ephemerides are referenced to the Parametry Zemli 1990 (PZ-90) geodetic datum, and GLONASS
ephemeris information is available through the GEPA/B log. GLONASS coordinates are reconciled internally
through a position filter and output to WGS84. Refer to the SVDA/B log in the MiLLennium Command
Descriptions Manual for information on WGS84.
GEPA
Structure:
NOTE:
1
Time offset = 3 hours + GPS UTC offset. See Section 1.5 (Page 13) for more information on GLONASS and GPS time.
$GEPA week seconds ephweek ephtime time offset
svid freq issue health posX posY posZ
velX velY velZ LSAccX LSAccY LSAccZ tau
gamma tk age flags *xx [CR][LF]
Field # Field Description Example
1 $GEPA Log Header $GEPA
2 Week GPS Week of log output 991
3 Seconds GPS Time of log output 496487
4 EphWeek Reference week of ephemeris (in GPS time) 991
5 EphTime Reference time of ephemeris (in GPS time) 495913
6 Time offset Integer seconds between GPS and GLONASS Time + implies
GLONASS ahead of GPS
10787
1
7 SVID Slot number for satellite 4
8 Freq Frequency number for satellite 12
9 Issue 15-minute interval number corresponding to ephemeris reference
time 83
10 Health Ephemeris Health (0 = GOOD, 1 = BAD) 0
11 PosX X coordinate for satellite at reference time (PZ90), in meters -2.102581933007
12 PosY Y coordinate for satellite at reference time (PZ90), in meters -1.216645166007
13 PosZ Z coordinate for satellite at reference time (PZ90), in meters 7.7982763671006
14 VelX X coordinate for satellite velocity at reference time (PZ90), in
meters/s -9.655075073002
15 VelY Y coordinate for satellite velocity at reference time (PZ90), in
meters/s -5.014476776002
16 VelZ Z coordinate for satellite velocity at reference time (PZ90), in
meters/s -3.387468338003
17 LSAccX X coordinate for lunisolar acceleration at reference time (PZ90), in
meters/s/s -1.862645149230957E-006
18 LSAccY Y coordinate for lunisolar acceleration at reference time (PZ90), in
meters/s/s 9.3132257461547851E-007
19 LSAccZ Z coordinate for lunisolar acceleration at reference time (PZ90), in
meters/s/s -9.313225746154785E-007
20 Tau Clock offset from GLONASS time, in seconds -3.913920372724533E-004
21 Gamma Frequency Correction, in seconds/second 7.2759576141834267E-012
22 Tk Time of frame start (since start of GLONASS day), in seconds 73800
23 Age Age of data, in days 0
24 Flags Information flags (see Table H.1, Page 94) 13
25 *xx Checksum *49
26 [CR][LF] Sentence Terminator [CR][LF]