[ros-users] Occupancy grid map with customized sensor model

Hi everyone!

I was wondering if I am correct in my assumption that the costmap2D is not
representing likelihoods of obstacles in the environment but assumes the
sensor readings are more or less perfect and the values in the grid cells
represent likelihoods of collisions with the robot.
(As opposed to the classical occupancy grid mapping proposed by Moravec
and Elfes).

If I am right, is there another ROS module for this job, preferably less
sophisticated than gmapping?

If I am wrong, is there a "default" way to include new sensor models for
e.g. updates from camera, sonar, etc. to better model these sensor's
characteristics and uncertainties?

Thanks a lot!
Dan