RAWIMUX

IMU Data Extended

Platform: 

OEM719, OEM729, OEM7500, OEM7600, OEM7700, OEM7720, PwrPak7, CPT7, CPT7700, SMART7-S

This log is an extended version of the RAWIMU log intended for use with post-processing. The extended version includes IMU information that is used by the NovAtel Inertial Explorer post-processing software.

The change in velocity (acceleration) and angle (rotation rate) scale factors for each IMU type can be found in Table: Raw IMU Scale Factors. Multiply the appropriate scale factor by the count value for the velocity (field 7-9) and angle (field 10-12) increments.

 

To obtain acceleration in m/s/s or rotation rate in rad/s, multiply the velocity/rotation increments by the output rate of the IMU:

  • 100 Hz for UIMU-HG1700-AG58, UIMU-HG1700-AG62, IMU-HG1900, OEM-HG1900, OEM-HG1930, OEM-IMU-HG4930, CPT7 and CPT7700

  • 125 Hz for IMU-IGM-S1, OEM-IMU-STIM300, OEM-IMU-EG320N, PwrPak7-E1, PwrPak7D-E1 and SMART7-S

  • 200 Hz for IMU-ISA-100C, IMU-FSAS, IMU-LN200, IMU-LN200C, IMU-µIMU-IC, OEM-IMU-µIMU-IC, IMU-KVH1750, IMU-P1750, IMU-IGM-A1, OEM-IMU-ADIS-16488, OEM-IMU-EG370N, OEM-IMU-EG320N_200Hz, PwrPak7-E2 and PwrPak7D-E2

  • 400 Hz for OEM-IMU-HG4930_400Hz, CPT7_400Hz, CPT7700_400Hz and OEM-IMU-µIMU-IC-UART

The units of acceleration and rotation rate will depend on the IMU Scale Factors.

This log is output in the IMU Body frame.

 

Logging Restriction Important Notice

Logging excessive amounts of high rate data can overload the system. When configuring the output for SPAN, NovAtel recommends that only one high rate (>50Hz) message be configured for output at a time. It is possible to log more than one message at high rates, but doing so could have negative impacts on the system. Also, if logging 100/125/200/400Hz data, always use the binary format and, if possible, the short header binary format (available on most INS logs).

For optimal performance, log only one high rate output at a time. These logs could be:

  • Raw data for post processing
    RAWIMUXSB ONNEW

    • RAWIMU logs are not valid with the ONTIME trigger. The raw IMU observations contained in these logs are sequential changes in velocity and rotation. As such, you can only use them for navigation if they are logged at their full rate.

  • Real time INS solution
    IMURATEPVA ONNEW or IMURATEPVAS ONNEW

    Other possible INS solution logs available at high rates are: INSPVASB, INSPOSSB, INSVELSB, INSATTSB

Message ID: 1461

Log Type: Asynch

Recommended Input:

log rawimuxb onnew

ASCII example:

#RAWIMUXA,USB1,0,64.5,FINESTEERING,2209,491740.110,02000020,0dc5,16809;04,41,2209,491740.109817,ea57fe00,329394068,-2396829,4481425,321199,257329,-936077*cf9c035d

Field

Field Type

Description

Format

Binary Bytes

Binary Offset

1

Log header

RAWIMUX header

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

-

H

0

2

IMU Info

IMU Info Bits

Bit 0: If set, an IMU error was detected. Check the IMU Status field for details.

Bit 1: If set, the IMU data is encrypted and should not be used.

Bits 2 to 7: Reserved

Hex Uchar

1

H

3

IMU Type

IMU Type identifier.

See Table: IMU Type.

Uchar

1

H+1

4

GNSS Week

GNSS Week

Ushort

2

H+2

5

GNSS Week Seconds

Seconds from week start

Double

8

H+4

6

IMU Status

The status of the IMU. This field is given in a fixed length (n) array of bytes in binary but in ASCII or Abbreviated ASCII is converted into 2 character hexadecimal pairs.

For the raw IMU status, see one of the following tables:

Hex Ulong

4

H+12

7

Z Accel

Change in velocity count along Z-axis.

Long

4

H+16

8

-(Y Accel)

- (Change in velocity count along y-axis.)

A negative value implies the output is along the positive y-axis marked on the IMU. A positive value implies the change is in the direction opposite to that of the y-axis marked on the IMU.

Long

4

H+20

9

X Accel

Change in velocity count along x axis.

Long

4

H+24

10

Z Gyro

Change in angle count around z axis.
Right-handed

Long

4

H+28

11

-(Y Gyro)

- (Change in angle count around y axis.)
Right-handed

A negative value implies a positive right-handed rotation about the y-axis marked on the IMU. A positive value implies a negative right-handed rotation about the y-axis marked on the IMU.

Long

4

H+32

12

X Gyro

Change in angle count around x axis.
Right-handed

Long

4

H+36

13

XXXX

32-bit CRC (ASCII, Binary, and Short Binary only)

Hex

4

H+40

14

[CR][LF]

Sentence terminator (ASCII only)

-

-

-