ICP odometry with GPS: /odom or /gps/fix

[dave-ms]

We're trying to run ICP odometry on a vehicle with GPS (and possibly IMU). Can we feed the GPS signal through /odom (odom_topic), or is it better to use /gps/fix (gps_topic)?

[matlabbe]

Hi,

If your /odom topic is accurate (like GPS RTK at fast rate), yes you could feed the pose directly to rtabmap node. If GPS is not accurate, use /gps/fix with Optimizer/PriorsIgnored=false to optimize the graph based on GPS factors. You will then need another high frequency odometry input (e.g., icp_odometry). See also those posts:
http://official-rtab-map-forum.206.s1.nabble.com/Mapping-and-GPS-Orientation-Problems-tp8090p8403.html
http://official-rtab-map-forum.206.s1.nabble.com/Is-this-the-way-to-use-lidar-amp-IMU-efficiently-td7496.html#a7515

cheers,
Mathieu