robot_localization - IMU orientation query
I am trying to use robot_localization to fuse data from a BNO055 IMU & a MTK3339 GPS receiver. I have what appears to be sensible output coming out of the system, however I would like to clarify one thing about the IMU orientation.
My launch file is linked below [1] & sets up a nmea_topic_driver to convert raw NMEA messages from the MTK3339 into NavSatFix messages, then a navsat_transform_node & a ukf_localization_node. The outputs that I am interested in are filtered IMU data (as orientation in x,y,z Euler angles) & filtered GPS data (as latitude & longitude) so I am subscribing to /odometry/filtered (which I then convert from quaternion to Euler) & /gps/filtered.
The quick start guide for the BNO055 [2] shows on page 4 that it outputs orientation data in the ENU convention expected by REP-0103 & robot_localization, except that it gives 0° at North rather than East, so I have set yaw_offset for navsat_transform_node to 1.5707963 as explained by the doc. However there doesn't appear to be an equivalent parameter for the ukf_localization_node. Do I need to specify this 90° in the transform between base_link frame & imu frame?
Any other input on other parts of my setup that may be wrong are of course welcomed!