BeiDou III CNAV ephemeris report
The BeiDou III CNAV ephemeris report is sent when Command Packet 54h is used to request the ephemeris for one BeiDou satellite or all BeiDou satellites. The GETSVDATA SUBTYPE byte (byte 4) is set to twenty-seven (27) to request the report. The first table below shows the additional records provided in Report Packet 55h when BeiDou ephemeris data is included.
The ephemeris data follows the standard defined by the BeiDou Interface Control Document (ICD).
|
Subtype 27: BeiDou III CNAV ephemeris data |
|||
|---|---|---|---|
|
Byte |
Item |
Type |
Meaning |
|
6 |
DATA SOURCE |
1 (byte) |
Valid values are: 3: B1C, 4: B2A, 5: B2B |
|
7–8 |
WEEK NUMBER |
2 (bytes) |
GPS Time |
|
9–12 |
TOW |
4 (bytes) |
seconds - GPS Time |
|
13–16 |
TOE |
4 (bytes) |
seconds - GPS Time |
|
17 |
SateType |
1 (byte) |
GEO=1, IGSO=2, MEO=3 |
|
18 |
Reserved |
1 (byte) |
|
|
19 |
IODE |
1 (byte) |
|
|
20–27 |
delta_A |
8 (double) |
meters |
|
28–35 |
A_DOT |
8 (double) |
meter / sec |
|
36–43 |
delta_N0 |
8 (double) |
semi-circles / sec |
|
44–51 |
delta_Ndot |
8 (double) |
semi-circles / sec2 |
|
52–59 |
M0 |
8 (double) |
semi-circles |
|
60–67 |
e |
8 (double) |
|
|
68–75 |
OMEGA |
8 (double) |
semi-circles |
|
76–83 |
OMEGSUB0 |
8 (double) |
semi-circles |
|
84–91 |
ISUB0 |
8 (double) |
semi-circles |
|
92–99 |
OMEGADOT |
8 (double) |
semi-circles / sec |
|
100–107 |
IDOT |
8 (double) |
semi-circles / sec |
|
108–115 |
CIS |
8 (double) |
semi-circles |
|
116–123 |
CIC |
8 (double) |
semi-circles |
|
124–131 |
CRS |
8 (double) |
meters |
|
132–139 |
CRC |
8 (double) |
meters |
|
140–147 |
CUS |
8 (double) |
semi-circles |
|
148–155 |
CUC |
8 (double) |
semi-circles |
|
156–159 |
TOC |
4 (long) |
seconds (GPS Time) |
|
160–161 |
IODC |
2 (short) |
|
|
162–169 |
A0 |
8 (double) |
seconds |
|
170–177 |
A1 |
8 (double) |
seconds /second |
|
178–185 |
A2 |
8 (double) |
seconds /second2 |
|
186–193 |
TGD_B1CP |
8 (double) |
seconds |
|
194–201 |
TGD_B2AP |
8 (double) |
seconds |
|
202–209 |
TGD_B2BI |
8 (double) |
seconds |
|
210–217 |
ISC_B1CD |
8 (double) |
seconds |
|
218–225 |
ISC_B2AD |
8 (double) |
seconds |
|
226–229 |
TOP |
4 (long) |
seconds (GPS Time) |
|
230 |
SISMAI |
1 (byte) |
|
|
231 |
SISAI_OE |
1 (byte) |
|
|
232 |
SISAI_OCB |
1 (byte) |
|
|
233 |
SISAI_OC1 |
1 (byte) |
|
|
234 |
SISAI_OC2 |
1 (byte) |
|
|
235–238 |
FLAGS |
4 (long) |
See below table |
|
---------- End of Subtype 27 ---------- |
|||
Where FLAGS is encoded as a 32-bit value given by the following table:
|
Bit(s) |
Description |
|---|---|
|
0 |
TGD B1CP Loaded (1 = loaded) |
|
1 |
TGD B2Ap Loaded (1 = loaded) |
|
2 |
TGD B2Bi Loaded (1 = loaded) |
|
3 |
ISC B1CD Loaded (1 = loaded) |
|
4 |
ISC B2AD Loaded (1 = loaded) |
|
5 |
1:Healthy, 0:Unhealthy |
|
6 |
ICD Reserved |
|
7 |
B1C integrity flags Loaded (1 = loaded) |
|
8 |
B1C Data integrity (1: Broadcasted parameters does not exceed the prediction accuracy) |
|
9 |
B1C Signal integrity (1: Signal is normal) |
|
10 |
B1C Accuracy integrity (1: SISMAI is valid) |
|
11 |
B2A integrity flags Loaded (1 = loaded) |
|
12 |
B2A Data integrity (1: Broadcasted parameters does not exceed the prediction accuracy) |
|
13 |
B2A Signal integrity (1: Signal is normal) |
|
14 |
B2A Accuracy integrity (1: SISMAI is valid) |
|
15 |
B2B integrity flags Loaded (1 = loaded) |
|
16 |
B2B Data integrity (1: Broadcasted parameters does not exceed the prediction accuracy) |
|
17 |
B2B Signal integrity (1: Signal is normal) |
|
18 |
B2B Accuracy integrity (1: SISMAI is valid) |
|
19–31 |
Reserved |