RANGECMP

Compressed version of the RANGE log

Platform:

OEM719, OEM729, OEM7500, OEM7600, OEM7700, OEM7720, PwrPak7, CPT7, CPT7700, SMART7, SMART2

This log contains the RANGE data in a compressed format.

 

For dual antenna receivers, a RANGECMP_1 log can be requested to get RANGECMP data from the second antenna. As described in Table: Binary message header structure, the message type indicates the log is from the second antenna. To request an ASCII log enter RANGECMPA_1, and for a binary log enter RANGECMPB_1.

The RANGECMP and RANGECMP_1 logs use the same message ID.

 

  • The Phase locked flag and Code locked flag are reported in RANGECMP. Those two bits should be used to interpret the validity of ADR or PSR. The ADR is valid when Phase locked flag is set, and the PSR and Doppler are valid when Code locked flag is set. 

  • In firmware 7.10.xx, the ADR std field may not be big enough. 7.10.xx firmware will track more noisy signals, which means the ADR std may be larger than what the log field can accommodate.

  • RANGECMP is not recommended for OEM 7.10.xx firmware release. Use the RANGECMP5 log instead.

Message ID: 140

Log type: Synch

Recommended input:

log rangecmpa ontime 10

ASCII example:

#RANGECMPA,USB1,0,54.5,FINESTEERING,2209,512487.000,02000020,9691,16809;154,

04dc1018c2e70a40d6a37b0b9fb702f5531a616f20030000,

0b5c3011667f08400ea47b0bf32b559f501a546f20030000,

0bdc3002667f08f00aa47b0bb027559f631a5d6fe0020000,

04dcd001dd2408400aa47b0bc1e906de301a0e7440030000,

24dc1008122cf77f198ebc0ab3e387f221025f7bc0030000,

2b5c3001041ff96f1a8ebc0a0e1324812002e87560030000,

44dc1008fa5d0c6073fa260b0a8d9fac32124d7b80030000,

4b5c300100a309f097fa260b0cc9aaca4012e87520030000,

4bdc300200a309309dfa260bcaccaaca32124b7680030000,

44dcd001303c09e0c3fa260b1b378e8710127976e0030000,

449c1042175e0c607efa260b4b7e9fac30127a7680030000,

64dc10180ea8f00f2091680bcb3e8a81420c3e7b40030000,

6b5c3011410bf43f4991680b5b9218a9400c187600030000,

6bdc3002420bf47f4b91680b189518a9430c557640030000,

...

24de15181dcb00b02e50bd1457da6be063c25179e0020000,

649f14086ea6fd7fdfa6500a20df2dc9200b2b7be0030000,

64df3400ca2efe2fe2a6500ad00de6ce100b7476e0030000,

64df54002e17fe9fe3a6500a0b35518b200b5976c0030000,

849f1408c398f57f19a0dc0b79e06fc7400cef7920030000,

84df3410a5f4f73f29a0dc0bac969887210c6e7680030000,

84df5400f18bf74f28a0dc0bcb6ce1b9300c547640030000,

c49f14081d9a0d101c032b0c6dfa6994500e837ae0020000,

c4df341087840a504a032b0c8a2e24e0420e7a7620030000,

c4df5400900d0bf040032b0c9d7c6b90510e6176c0020000,

e49f1408a208f76f49cfe30b1bbac2c22017117880030000,

e4dff400a9f3f6ff35cfe30ba97395b04217527660030000,

e4df34013c3ef92f51cfe30bf503eeaa1017c175e0030000,

e43f74011a11f91f49cfe30b8bebfa832017547680030000,

e4df5400e2b6f86f34cfe30bbeb814b63017547600030000*5bf4bd0a

Field

Field type

Description

Format

Binary bytes

Binary offset

1

Log header

RANGECMP header

For information about log headers, see ASCII, Abbreviated ASCII or Binary.

 

H

0

2

#obs

Number of satellite observations with information to follow

Ulong

4

H

3

1st range record

Compressed range log in format of Table: Range record format (RANGECMP only)

Hex

24

H+4

4

Next rangecmp offset = H+4 (#obs x 24)

5

xxxx

32-bit CRC (ASCII and Binary only)

Ulong

4

H+4+
(#obs x 24)

6

[CR][LF]

Sentence terminator (ASCII only)

-

-

-
Range record format (RANGECMP only)

Data

Description

Bits first to last

Length (bits)

Scale factor

Units

Channel Tracking Status

Channel tracking status word

0-31

32

see Table: Channel tracking status

-

Doppler Frequency

Instantaneous carrier Doppler frequency

32-59

28

1/256

Hz

Pseudorange (PSR)

Pseudorange measurement

60-95

36

1/128

m

ADR

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_ROLLS + 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

GLONASS satellites emit L1 and L2 carrier waves at a satellite-specific frequency, refer to the GLONASS section of An Introduction to GNSS available on our website at novatel.com/an-introduction-to-gnss

96-127

32

1/256

cycles

StdDev-PSR

Pseudorange measurement standard deviation

128-131

4

See Table: StdDev-PSR values

m

StdDev-ADR

ADR measurement standard deviation

132-135

4

(n+1)/512

cycles

PRN/Slot

Refer to PRN numbers

136-143

8

1

-

Lock Time

Number of seconds of continuous tracking (no cycle slipping)

This field is constrained to a maximum value of 2,097,151 which represents a lock time of 65535.96875 s (2097151/32).

144-164

21

1/32

s

C/No

Carrier to noise density ratio

The 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, the true value could be greater.

165‑169

5

(20+n)

dB-Hz

GLONASS Frequency number

GLONASS Frequency number

170-175

n+7

1

 

Reserved

176‑191

16
StdDev-PSR values

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

11

9.500

12

19.000

13

38.000

14

76.000

15

152.000