Odometry Covariances

[pamarinp]

Hello, I would like to know if there is an implementation of generating the covariances and the odometry messages in ROS. We developed a "velodyne_odometry" which uses loam Velodyne output and publish odometry.msg but without covariance (we try to estimate with the velocity of the vehicle and the total number of points but it is really inaccurate). Could you orientate us on how to extract the covariance for each topic published of odometry? We read the original paper and the part of "Then, we compute the covariance matrix of S', denoted as M, and the eigenvalues and eigenvectors of M, denoted as V and E, respectively" is promising.