Byning the earth

Abstract

The Corps Battle Simulation (CBS) simulates ground and air battles between modern military forces. It runs in real time, modeling the interactions of tens of thousands of units in support of U.S. Army training exercises, typically involving several sites at geographically separated locations around the world. Through Version 1.5.2, the CBS terrain database associated terrain characteristics with a regular grid of three-kilometer hexagons tiling an appropriate map projection of the playbox. The hexagons also served as bins for other location-dependent information to simplify the search for what's nearby. This paper presents a new way to describe locations: Bynary latitudes and longitudes define patches of various sizes that completely cover the globe. Large patches, not necessarily all the same size, can serve as bins. Medium-sized patches can be assumed to have uniform terrain characteristics throughout. (That assumption, however, has not been used in CBS Version 1.5.3.) Tiny patches are suitable descriptors of locations. Spherical coordinates (latitudes and longitudes) are used for fundamental specification of locations, so playboxes are not limited by the characteristics of a map projection. The natural data structure is a quadtree, which facilitates storing terrain (and other location-dependent) data in variable size bins. If desired, huge bins can be used for areas remote from the primary theater of operations and smaller bins can be used in battle zones.