Trimble Outdoors 58052-00 GPS Receiver User Manual


 
A TRIMBLE STANDARD INTERFACE PROTOCOL (TSIP)
152 Copernicus GPS Receiver
Report Packet 0x5A - Raw Measurement Data
This packet provides raw GPS measurement data. If the I/O Auxiliary options has
been selected, the receive sends this data automatically as measurements are taken.
The data format is shows in the table below.
Note – Packet 0x5A provides the raw satellite signal measurement information used
in computing a fix.
Satellite PRN (Byte 0) is a unique identification number for each of the 32 GPS
satellites. The integer millisecond of the pseudo-range has valid values of 0 to 19
milliseconds. If the pseudo-range is out of bounds, this is indicated by setting Bit 7 of
Byte 4 to 1.
The codephase (Byte 9) value is the average delay over the sample interval of the
received C/A code and is measured with respect to the receiver’s millisecond timing
reference. Thus, it includes all receiver satellite, and propagation biases and errors. It
is expressed in 1/16th of a C/A code chip.
The Doppler (Byte 13) value is apparent carrier frequency offset averaged over the
sample interval. It is measured with respect to the nominal GPS L1 frequency of
1575.42 MHz, referenced to the receiver’s internal oscillator. Thus int includes all
receiver and satellite clock frequency errors. It is expressed in Hertz at the L1 carrier.
The time of measurement (Byte 17) is the center of the sample interval adjusted by
adding the receiver supplied codephase (module mS) to a user determined integer
number of mS between user and satellite.
139-146 n Double derived from delta_n
147-154 r1me2 Double = sqrt(1.0-e
2
)
155-162 OMEGA_n Double derived from OMEGA_0,
OMEGADOT
163-170 ODOT_n Double derived from OMEGADOT
Table A.45 Report Packet 0x5A Data Formats
Byte Item Type Units
0 Satellite PRN number UINT8 ----
1-3 reserved
4 Integer msec of pseudo-
range
If Bit 7 =1, pseudo-range is
out of bounds
UINT 8 msec
5 Signal level Single AMU or dBHz
9 Code phase Single 1/16th chip
13 Doppler Single hertz
17 Time of Measurement Double sec
Table A.44 (continued)
Byte Item Type Definition / IDC -GPS-200