GLOCLOCK
GLONASS L1 C/A clock information
|
Platform: |
OEM719, OEM729, OEM7500, OEM7600, OEM7700, OEM7720, PwrPak7, CPT7, CPT7700, SMART7, SMART2 |
This log contains the time difference information between GPS and GLONASS time as well as status flags. The status flags are used to indicate the type of time processing used in the least squares adjustment. GPS and GLONASS time are both based on the Universal Time Coordinated (UTC) time scale with some adjustments. GPS reference time is continuous and does not include any of the leap second adjustments to UTC applied since 1980. The result is that GPS reference time currently leads UTC time by 15 seconds.
GLONASS time applies leap seconds but is also three hours ahead to represent Moscow time. The nominal offset between GPS and GLONASS time is therefore due to the three hour offset minus the leap second offset. As well as the nominal offset, there is a residual offset on the order of nanoseconds which must be estimated in the least squares adjustment. The GLONASS-M satellites broadcasts this difference in the navigation message.
This log also contains information from the GLONASS navigation data relating GLONASS time to UTC.
Message ID: 719
Log Type: Asynch
Recommended Input:
log gloclocka onchanged
ASCII Example:
#GLOCLOCKA,USB1,0,53.0,SATTIME,2209,504978.000,02000020,1d44,16809;
0,0.000000000,0.000000000,1,7,4.749745131e-08,864,4.656612873e-10,
-0.095703125,-0.000656128,0*668057a7
|
Field |
Field type |
Description |
Format |
Binary Bytes |
Binary Offset |
|
1 |
Log header |
GLOCLOCK header For information about log headers, see ASCII, Abbreviated ASCII or Binary. |
|
H |
0 |
|
2 |
Reserved |
Ulong |
4 |
H |
|
|
3 |
Double |
8 |
H+4 |
||
|
4 |
Double |
8 |
H+12 |
||
|
5 |
sat type |
Satellite type where 0 = GLO_SAT 1 = GLO_SAT_M (M type) 2 = GLO_SAT_K (K type) |
Uchar |
1 |
H+20 |
|
6 |
N4 |
Four-year interval number starting from 1996 |
Uchar |
1 1 |
H+21 |
|
7 |
τGPS |
Correction to GPS time relative to GLONASS time |
Double |
8 |
H+24 |
|
8 |
NA |
GLONASS calendar day number within a four year period beginning since the leap year, in days |
Ushort |
2 1 |
H+32 |
|
9 |
τC |
GLONASS time scale correction to UTC(SU) given at beginning of day N4 (s) |
Double |
8 |
H+36 |
|
10 |
b1 |
Beta parameter 1st order term |
Double |
8 |
H+44 |
|
11 |
b2 |
Beta parameter 2nd order term |
Double |
8 |
H+52 |
|
12 |
Kp |
Kp provides notification of the next expected leap second. For more information, see Table: Kp UTC Leap Second Descriptions |
Uchar |
1 |
H+60 |
|
13 |
xxxx |
32-bit CRC (ASCII and Binary only) |
Ulong |
4 |
H+61 |
|
14 |
[CR][LF] |
Sentence terminator (ASCII only) |
- |
- |
- |
|
Kp |
Information on UTC Leap Second2 |
|
00 |
No UTC update for this quarter |
|
01 |
UTC update of plus 1 second at the end of current quarter |
|
11 |
UTC update of minus 1 second at end of current quarter |