A detailed IR sensor simulation has been developed which models the IR scene and optical system for a variety of space-based military missions including SDI and ADI. The IR scene model includes a background radiance map, a foreground map (such as clouds), and a target map. This target map includes a hardbody radiance as well as plume radiances for a variety of boosting or afterburning targets. The scene generation portion of the software includes the combination of the various scene elements into a high resolution map which is then propagated through the atmosphere to the sensor. The atmospheric transmission and turbulence effects are estimated and included in the simulation. The actual sensor performance is then simulated using a two-dimensional Modulation Transfer Function (MTF) which includes errors due to low frequency aberrations, mid and high spatial frequency surface roughness, diffraction effects, and image motion. This sensor MTF is then multiplied by the Fourier Transform of the high resolution IR scene, and then transformed back to the spatial domain, to produce the high resolution blurred scene which is incident on the detector focal plane array (FPA). Finally, the software simulates the FPA and electronic components to arrive at the sampled, low resolution output from the detector. Detector parameters including gain, bias, crosstalk, quantum efficiency and electronics noise, photon noise statistics, and A/D conversion are all simulated in the model.