D Logs summary
MiLLennium Command Descriptions Manual 183Table D-6 Range Record Format (RGED only)
Notes on Table D-6:
Only PRNs 1 - 63 are reported correctly (Note: while there are only 32 PRNs in the basic GPS scheme,
situations exist which require the use of additional PRNs)
C/No is constrained to a value between 20 - 51 dB-Hz. Thus, if it is reported that C/No = 20 dB-Hz, the
actual value could be less. Likewise, if it is reported that C/No = 51 dB-Hz, the true value could be greater.
Lock time rolls over after 2,097,151 seconds.
ADR (Accumulated Doppler Range) is calculated as follows:
ADR_ROLLS = [( -RGED_PSR / WAVELENGTH - RGED_ADR)] / MAX_VALUE
IF (ADR_ROLLS -0.5)
ADR_ROLLS = ADR_ROLLS - 0.5
ELSE ADR_ROLLS = ADR_ROLLS + 0.5 (At this point integerise ADR_ROLLS)
CORRECTED_ADR = RGED_ADR + (MAX_VALUE * ADR_ROLLS)
where:
ADR has units of cycles
WAVELENGTH = 0.1902936727984 for L1
WAVELENGTH = 0.2442102134246 for L2
MAX_VALUE = 8388608
Only bits 0 - 23 are represented in the RGED log
Data Bit(s) from first to last Length (bits) Format Scale Factor
PRN 0..5 6 integer 1
C/No 6..10 5 integer (20+n) dB-Hz
Lock time 11.31 21 integer 1/32 s
ADR 32..63 32 integer 2's comp. 1/256 cycles
Doppler frequency 68..95 28 integer 2's comp. 1/256 Hz
Pseudorange 64..67 msn; 96..127 lsw 36 integer 2's comp. 1/128 m
StdDev - ADR 128..131 4 integer (n+1) / 512 cyc
StdDev - pseudorange 132..135 4 see
Channel Tracking status 136..159 24 integer see Table D-7
Code RGED
00.000 to 0.050
1 0.051 to 0.075
2 0.076 to 0.113
3 0.114 to 0.169
4 0.170 to 0.253
5 0.254 to 0.380
6 0.381 to 0.570
7 0.571 to 0.854
8 0.855 to 1.281
9 1.282 to 2.375
10 2.376 to 4.750
11 4.751 to 9.500
12 9.501 to 19.000
13 19.001 to 38.000
14 38.001 to 76.000
15 76.001 to 152.000