This paper presents the VDM2000, a computational model of target detection designed for use in military developmental test and evaluation settings. The model integrates research results from the fields of early vision, object recognition, and psychophysics. The VDM2000 is image based and provides a criterion-independent measure of target conspicuity, referred to as the vehicle metric (VM). A large data set of human responses to photographs of military vehicles in a field setting was used to validate the model. The VM adjusted by a single calibration parameter accounts for approximately 80% of the variance in the validation data. The primary application of this model is to predict detection of military targets in daylight with the unaided eye. The model also has application to target detection prediction using infrared night vision systems. The model has potential as a tool to evaluate the visual properties of more general task settings.