41
/
49
5
xxxx
32-bit CRC (ASCII and Binary only)
Ulong
4
H+4+
(#obs
x 24)
6
[CR][LF]
Sentence terminator (ASCII only)
-
-
-
Table 59 Range Record Format
Data
Bits first to last
Length(bits)
Scale Factory
Units
Channel Tracking Status
0-31
32
-
Doppler Frequency
32-59
28
1/256
hz
Pseudorange (PSR)
60-95
36
1/128
m
ADR
96-127
32
1/256
cycles
StdDev-PSR(1)
128-131
4
See (2)
m
StdDev-ADR
132-135
4
(n+1)/512
cycles
PRN/Slot(3)
136-143
8
1
-
Lock Time(4)
144-164
21
1/32
s
C/No(5)
165-169
5
(20+n)
dB-Hz
Reserved
170-191
22
1.
ADR (Accumulated Doppler Range) is calculated as follows:
ADR_ROLLS = (RANGECMP_PSR / WAVELENGTH + RANGECMP_ADR) /
MAX_VALUE
Round to the closest integer
IF (ADR_ROLLS <= 0) ADR_ROLLS = ADR_ROLLS - 0.5
ELSE ADR_ROLLS = ADR 0.5
At this point integerise ADR_ROLLS
CORRECTED_ADR = RANGECMP_ADR - (MAX_VALUE*ADR_ROLLS)
where ADR has units of cycles
WAVELENGTH = 0.1902936727984 for GPS L1
WAVELENGTH = 0.2442102134246 for GPS L2
MAX_VALUE = 8388608
Note: GLONASS satellites emit L1 and L2 carrier waves at a satellite-specific frequency, refer to
the GLONASS section of An Introduction to GNSS
2.
Code StdDev-PSR (m)
0
0.050
1 0.075
2
0.113
3 0.169
4 0.253
5 0.380
6 0.570
7 0.854
8 1.281
9 2.375
10 4.750