Hi, I have been having this problem for a week or so.

I am trying to fuse the GPS position with an IMU simulated in Gazebo(hectorsensors) with the robotlocalization package (with one EKF node and one navsat node ). So far it everything was OK, I rotated everything as the REP103 states and the data seems to give good covariances. However, the GPS(or the navsat node rather) has a steady drift of approximately 1~2º in the /odometry/gps & /odometry/filtered topics and after traveling a long distance , it becomes a problem. The movement is along the Y axis, but after 100 meters or so, it drifts a meter on the y axis.

It seems to be an extra rotation and I cannot retrieve the proper coordinates( i.e. getting the global reference of the robot). At first I though it should be rotated with the utm->odom transform published by navsattransformnode but I can't figure it out how.

Do you know what my problem is?, i am almost certain that it has to be something regarding the map-utm transformation but can't get it to work.

Launchfiles: Navsat: , EKF

Yaml config parameters Navsat , EKF

Sensor model gazebo model.sdf

And a photo of the odometry results

Thanks a lot, it you need anything else let me know.