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EuroPak-15a Receiver User Manual Rev 5
Chapter 6
Data Logs
6.3.5
RANGE
Satellite Range Information
RANGE
contains the channel measurements for the currently tracked satellites. When using this log, please
keep in mind the constraints noted along with the description.
It is important to ensure that the receiver clock model is valid. This can be monitored by the bits in the
Receiver
Status
field of the log header. Large jumps in pseudorange as well as accumulated Doppler range (ADR) will
occur as the clock is being adjusted. If the ADR measurement is being used in precise phase processing, it is
important not to use the ADR if the
parity known
flag in the
ch-tr-status
field is not set as there may exist a half
(1/2) cycle ambiguity on the measurement. The tracking error estimate of the pseudorange and carrier phase
(ADR) is the thermal noise of the receiver tracking loops only. It does not account for possible multipath errors
or atmospheric delays.
If a PRN is being tracked on more than one signal (GPS L1, GPS L5, Galileo L1 or Galileo E5a) multiple
entries with the same PRN will appear in the range logs. As shown in
differentiated by bits 21-22 of the
ch-tr-status
field, which denote whether the observation is for GPS L1, GPS
L5, Galileo L1 or Galileo E5a. This is to aid in parsing data.
Log Type: Synch
Message ID: 43
Field
Field
Name
Description
Format
Binary
Bytes
Binary
Offset
1
header
This field contains the message header, in
ASCII
or
Binary
format. See
H
0
2
# obs
Number of data sets to follow.
Long
4
H
3
PRN
Satellite PRN number of range measurement.
UShort
2
H+4
4
Reserved
UShort
2
H+6
5
psr
Pseudorange measurement (m).
Double
8
H+8
6
psr std
Pseudorange measurement standard deviation (m).
Float
4
H+16
7
adr
Carrier phase, in cycles (accumulated Doppler range).
Double
8
H+20
8
adr std
Estimated carrier phase standard deviation (cycles).
Float
4
H+28
9
dopp
Instantaneous carrier Doppler frequency (Hz).
Float
4
H+32
10
C/N0
Carrier to noise density ratio
C/N0 = 10[log10(S/N0)] (dB-Hz)
Float
4
H+36
11
locktime
Number of seconds of continuous tracking (no cycle
slipping).
Float
4
H+40
12
ch-tr-
status
ULong
4
H+44
13...
Next data set, offset = H + 4 + (# previous obs x 44)
variable
32-bit CRC (
ASCII
and
Binary
only)
Hex
4
H+4+
(#obs x
44)