Recent technology advances have made low cost, eye safe, high performance laser-range-gated (LRG) imagers a reality. These advances include the Electron Bombarded CCD sensor and the 1.5 micron, monoblock laser. LRG imagers use a laser beam to illuminate targets at extended ranges; the targets are then identified with the EBCCD sensor. Several features of LRG imagers make predicting range performance different than for passive imagers. LRG imagers are described. The features that make active imager performance different from passive imager performance are discussed. Features unique to active imagers include laser speckle in the image, the narrow illumination beam and its interaction with the atmosphere, the highly directional "spot light" illumination of the target, and the range gating of the receiver. This paper discusses the unique modeling requirements for LRG imagers.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.