Coherent laser radars offer new technical options for a variety of target detection and imaging scenarios. Such systems will, of necessity, be subject to the vagaries of atmospheric optical propagation, viz., turbulence, absorption, and scattering. This paper presents a mathematical system model for a compact heterodyne-reception laser radar which incorporates the statistical effects of target speckle and glint, local-oscillator shot noise, and propagation through either turbulent or turbid atmospheric conditions. Using this model, results are developed for the imace signal-to-noise ratio and target resolution capability of the radar. Clear-weather propagation through the turbulent atmosphere is shown to affect the compact laser radar primarily through scintillation. Low-visibility weather propagation is shown to degrade the resolution of the radar. Sample performance calculations for a realistic infrared radar are Included.