RAWIMUS

Short Raw IMU Data

Platform: 

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

This log is the short header version of the RAWIMU log.

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 5-7) and angle (field 8-10) 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: 325

Log Type: Asynch

Recommended Input:

log rawimusa onnew

ASCII Example:

%RAWIMUSA,2209,491612.254;2209,491612.253588,ea5afe00,329303960,-2512321,4410363,309705,607017,-1009773*1fb76c28

Field

Field Type

Description

Format

Binary Bytes

Binary Offset

1

Log header

RAWIMUS header

For information about short log headers, see Description of ASCII and Binary Logs with Short Headers.

-

H

0

2

Week

GNSS Week

Ulong

4

H

3

Seconds into Week

Seconds from week start

Double

8

H+4

4

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

5

Z Accel Output

Change in velocity count along z axis

Long

4

H+16

6

- (Y Accel Output)

- (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

7

X Accel Output

Change in velocity count along x axis

Long

4

H+24

8

Z Gyro Output

Change in angle count around z axis
Right-handed

Long

4

H+28

9

- (Y Gyro Output)

- (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

10

X Gyro Output

Change in angle count around x axis
Right-handed

Long

4

H+36

11

xxxx

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

Hex

4

H+40

12

[CR][LF]

Sentence terminator (ASCII only)

-

-

-