\subsubsection parameters ROS parameters

Reads and maintains the following parameters on the ROS server

- \b "~ring" : \b [int] Ring to extract as laser scan (-1 default) min: -1, default: -1, max: 31
- \b "~resolution" : \b [double] Laser scan angular resolution (rad) min: 0.001, default: 0.007, max: 0.05