INSSTDEV
INS PVA standard deviations
Platform: 
OEM719, OEM729, OEM7500, OEM7600, OEM7700, OEM7720, PwrPak7, CPT7, CPT7700, SMART7S 
This log displays the INS PVA standard deviations.
Message ID: 2051
Log Type: Synch
Abbreviated ASCII Syntax:
log insstdev ontime 1
ASCII Example:
#INSSTDEVA,USB1,0,66.0,FINESTEERING,2209,491004.000,02000020,2396,16809;0.1813,0.1813,0.1806,0.0018,0.0018,0.0017,0.0292,0.0291,0.0577,13000045,0,0,7fd1bf,0*b490ddee
Field 
Field Type 
Description 
Binary Format 
Binary Bytes 
Binary Offset 

1 
Log header 
INSSTDEV header For information about log headers, see ASCII, Abbreviated ASCII or Binary. 
 
H 
0 
2 
Latitude σ 
Latitude standard deviation (m) 
Float 
4 
H 
3 
Longitude σ 
Longitude standard deviation (m) 
Float 
4 
H+4 
4 
Height σ 
Height standard deviation (m) 
Float 
4 
H+8 
5 
North Velocity σ 
North velocity standard deviation (m/s) 
Float 
4 
H+12 
6 
East Velocity σ 
East velocity standard deviation (m/s) 
Float 
4 
H+16 
7 
Up Velocity σ 
Up velocity standard deviation (m/s) 
Float 
4 
H+20 
8 
Roll σ 
Roll standard deviation (degrees) 
Float 
4 
H+24 
9 
Pitch σ 
Pitch standard deviation (degrees) 
Float 
4 
H+28 
10 
Azimuth σ 
Azimuth standard deviation (degrees) 
Float 
4 
H+32 
11 
Ext sol stat 
Extended solution status 
Ulong 
4 
H+36 
12 
Time Since Update 
Elapsed time since the last ZUPT or position update (seconds) 
Ushort 
2 
H+40 
13 
Reserved 
Ushort 
2 
H+42 

14 
Reserved 
Ulong 
4 
H+44 

15 
Reserved 
Ulong 
4 
H+48 

16 
xxxx 
32bit CRC (ASCII and Binary only). 
Hex 
4 
H+52 
17 
[CR][LF] 
Sentence terminator (ASCII only). 
 
 
 
The INS standard deviation values reported by the SPAN filter are an estimate of the Inertial filter solution quality. In lower accuracy GNSS position modes, such as SINGLE or WAAS (see Table: Position or Velocity Type), the position standard deviation values can appear to become optimistic compared with the absolute GNSS accuracy. This is due to the INS filter’s ability to smooth short term noise in the GNSS solution, although the overall position error envelope still reflects the GNSS accuracy. Therefore, if the desired application requires absolute GNSS position accuracy, it is recommended to also monitor GNSS position messages such as BESTGNSSPOS (see BESTGNSSPOS log).