From MobileRobots Research and Academic Customer Support
ARNL, SONARNL, MOGS and MobileSim use a map to represent the robot's operating environment including known stationary objects such as walls and furniture, as well as logical objects such as goal points to navigate between, and areas and boundaries that are used to restrict or modify autonomous navigation. The map defines a cartesian world coordinate system, into which the robot's odometric coordinate system can be transformed, with localization corrections if using ARNL, SONARNL, or MOGS.
Maps can be loaded into MobileSim to represent a physical environment for the simulation.
Objects and obstacle points are represented by X, Y coordinates within in the map coordinate system. A resolution property of the map determines the size that an obstacle point should fill at a particular point. For example, at 1cm map resolution, a point at (Px, Py) fills a 1cm X 1cm square volume centered on the point (Px, Py).
Maps are stored in text files, with a filename usually ending in .map. The format of this file is described in the ARIA API reference manual.
ARIA can load and store map data from files, which can then be used by ARNL, SONARNL, MOGS or other software. The primary class interface for most programs is ArMap. See the ARIA examples and API reference documentation for details on using ArMap.
For more details on the steps required to scan an environment with the robot's laser rangefinder and automatically start creating a map for use with ARNL see Creating A Laser Map for ARNL and ARNL's "Mapping.txt" document.