SETINSTRANSLATION

Specifies translational offsets between the IMU frame and other reference frames

Platform: 

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

Use the SETINSTRANSLATION command to specify translational offsets between the IMU frame and other reference frames, including GNSS antennas or the desired output frame. Offsets must be entered as the vector from the IMU, to the frame or position of interest. Offsets can be entered either in the IMU body frame, or the vehicle frame; offsets in the vehicle frame will be automatically rotated into the IMU body frame using the best available IMU Body to Vehicle Rotation (RBV).

For details on entering the RBV rotation or other angular offsets, see the SETINSROTATION command.

Message ID: 1920

Abbreviated ASCII Syntax:

SETINSTRANSLATION INSTranslation XTranslation YTranslation ZTranslation [XTranslationSD] [YTranslationSD] [ZTranslationSD] [InputFrame]

Abbreviated ASCII Example:

SETINSTRANSLATION USER 1.0 2.0 3.0 0.05 0.05 0.05 VEHICLE

Field

Field Type

ASCII Value

Binary Value

Description

Binary Format

Binary Bytes

Binary Offset

1

SETINS
TRANSLATION Header

-

-

Command header. See Messages for more information.

-

H

0

2

InsTranslation

See Table: Translation Offset Types

Translation offset to be set

Enum

4

H

3

XTranslation

±100

X translation offset from IMU origin (m)

Float

4

H+4

4

YTranslation

±100

Y translation offset from IMU origin (m)

Float

4

H+8

5

ZTranslation

±100

Z translation offset from IMU origin (m)

Float

4

H+12

6

XTranslationSD

0 to 10

Optional X translation offset standard deviation (m)

Float

4

H+16

7

YTranslationSD

0 to 10

Optional Y translation offset standard deviation (m)

Float

4

H+20

8

ZTranslationSD

0 to 10

Optional Z translation offset standard deviation (m)

Float

4

H+24

9

InputFrame

Table: Translation Input Frame

Optional input frame for translation offset values

Enum

4

H+48

For the ANT1, ANT2, EXTERNAL and GIMBAL translations, the standard deviation defaults are set to 10% of the translation value (up to a max of 10 metres).

For USER, MARK1, MARK2, MARK3 and MARK4 translations, standard deviations values are not used in the solution.

Large standard deviations can lead to an inaccurate position solution. Therefore, it is highly recommended to measure translation offsets as accurately as possible and to manually enter translation offset standard deviations that reflect that accuracy.

It is important to keep in mind that as the user offset is moved further from the IMU center of navigation, the PVA solution will become noisier due to the projection of angular changes over a longer distance.

Translation Offset Types

ASCII
Value

Binary
Value

Description

ANT1

1

Offset from the IMU center of navigation to the phase center of the primary GNSS antenna.

Do not use the ANT1 option (SETINSTRANSLATION ANT1) on a SMART7-S. The correct lever arm value has been set at the factory.

ANT2

2

Offset from the IMU center of navigation to the phase center of the secondary GNSS antenna.

EXTERNAL

3

Offset from the IMU center of navigation to the external position source location.

This offset type is for use with the EXTERNALPVAS command.

USER

4

Translation from the IMU center of navigation to the user output location.

This offset shifts the position and velocity information in the INSPVA, INSPOS, INSVEL, INSATT, and INSSPD logs, along with their short header and extended versions.

MARK1

5

Translation from the IMU center of navigation to the MARK1 output location.

This offset shifts the position and velocity information in the MARK1PVA log.

MARK2

6

Translation from the IMU center of navigation to the MARK2 output location.

This offset shifts the position and velocity information in the MARK2PVA log.

GIMBAL

7

Translation from the IMU center of navigation to the gimbal mount center of rotation.

MARK3

9

Translation from the IMU center of navigation to the MARK3 output location.

This offset shifts the position and velocity information in the MARK3PVA log.

MARK4

10

Translation from the IMU center of navigation to the MARK4 output location.

This offset shifts the position and velocity information in the MARK4PVA log.

Translation Input Frame

ASCII
Value

Binary
Value

Description

IMUBODY

0

Offset is provided in the IMU enclosure frame.

Default: IMUBODY

VEHICLE

1

Offset is provided in the vehicle frame.

Offsets entered in the vehicle frame will be automatically rotated into the IMU frame using the best available RBV (rotation from IMU Body to Vehicle) information when required.

Vehicle frame offsets should only be used if the RBV is known accurately, either though user measurement or calibration.

The order of entry for vehicle frame offsets and the RBV rotation does not matter.