Revision history [back]

All messages that contain fields that represent a measurement of a physical quantity (should) always use SI units for those fields. That is certainly true for all core message sets. We can't guarantee that every author of every non-standard / non-core message pig has followed this requirement.

REP-103 documents this.

In the case of sensor_msgs/Imu, it's also stated in the comments in the .msg file itself:

Accelerations should be in m/s^2 (not in g's), and rotational velocity should be in rad/sec

Note also that the orientation field is a quaternion, not a RPYx quartet.

All messages that contain fields that represent a measurement of a physical quantity (should) always use SI units for those fields. That is certainly true for all core message sets. We can't guarantee that every author of every non-standard / non-core message pig has followed this requirement.

REP-103 documents this.

In the case of sensor_msgs/Imu, it's also stated in the comments in the .msg file itself:itself (second line of the comments in the file that you linked):

Accelerations should be in m/s^2 (not in g's), and rotational velocity should be in rad/sec

Note also that the orientation field is a quaternion, not a RPYx quartet.

All messages that contain fields that represent a measurement of a physical quantity (should) always use SI units for those fields. That is certainly true for all core message sets. REP-103 documents this. We can't guarantee that every author of every non-standard / non-core message pig has followed pkg adhered to this requirement.

REP-103 documents this.requirement though. The IMU msgs do however.

In the case of sensor_msgs/Imu, it's also stated in the comments in the .msg file itself (second line of the comments in the file that you linked):

Accelerations should be in m/s^2 (not in g's), and rotational velocity should be in rad/sec

Note also that the orientation field is a quaternion, not a RPYx quartet.