NavCom Sapphire Rev.J - Manual (Page 343)

Sapphire Technical Reference Manual Rev. J
343
2.91 PVT1B (Version 1; v0.3.0.3 and 2; v1.0.0.0) (Binary)
SF-3050 Sapphire SF-3040
In the Sapphire Core Navigation Module, several different navigation solutions may be
computed at a 1 Hz rate. For example, a navigation solution using global dGPS corrections from
the StarFire system may be computed in parallel with an independent RTK solution using
corrections from a local base station. For position, velocity, and time (PVT) output at rates
greater than 1 Hz, the Sapphire Core Navigation Module automatically selects the best available
source of position information to control the fast (>1 Hz) navigation process. The PVT1B binary
output stream contains this automatically selected navigation solution.

When the rover is operating in MBRTK, PVT1B is not impacted. PVT1B operates in
the mode based on the input correction format. In other words, if StarFire
corrections are being received, PVT1B will be in StarFire (5cm) operation and
MBRTK1B (with corrections from a moving base) will be at RTK levels.
This message is identical for version 1 (preproduction) and version 2 (production), except for a
single byte of status flags, on
e of which is populated for version 2, a flag denoting “Doppler
Used” in the solution. To minimize the change to the programs that read and format this
message, that single byte has been added at the very end of the message. Also note that this
adds 1 to the byte count previously known for version 1.
This message can vary in size based on the data in the field marked “GNSS satellite
constellation (bit mask, by satellite type)”. This bit mask denotes the data that follows it in the
message. This can be no additional data at all, or up to 24 additional bytes. Adding the 9 byte
binary header to the data described here, this is how the message size works out for each of the
combinations of bits in this field, with provision for versions 1 and 2 of this message:
The PVT1B message length is 76 bytes counted from 4C through 00 byte before 2A .
[PVT1B] 4C 00 76 06 20 7E 3E 1E 25 AF CF 50 E4 0E 91 20 32 CC 2D 5E CC 00 00 7A 76 FF
55 01 51 01 26 02 0A 0A 19 00 00 00 01 00 00 FE FF FF 10 22 64 00 00 00 2F 01 EC FF CA
FF 00 00 03 0A 0B 01 00 1A 0B 01 09 00 00 00 00 05 E0 03 00 00
2A 33 30 43 32 0D 0A
2A = aste risk ‘*’
33 30 43 32 = four characters of CRC. In this case, it is ‘0x30C2’
0D = carriage return ‘\r’
0A = new line ‘\n’
Table 175: PVT1B Version Size Differences
Data Bits in Constellation Mask Version 1 Message Size Version 2 Message Size
None 59 bytes 60 bytes
One of GPS, GLONASS or SBAS 67 bytes 68 bytes
Two of GPS, GLONASS or SBAS 75 bytes 76 bytes
All 83 bytes 84 bytes