Radiometric sensor performance model including atmospheric and IR clutter effects

The computer code SENSAT developed for radiometric investigations in remote sensing was extended to include two statistical clutter models of infrared background and the prediction of the target detection probability. The first one is based on the standard deviation of scene clutter estimated from scene data, the second one is based on the power spectral density of different classes of IR background as a function of temporal or spatial frequency. The overall code consists of modules describing the optoelectronic sensor (optics, detector, signal processor), a radiative transfer code (MODTRAN) to include the atmospheric effects, and the scene module consisting of target and background. The scene is evaluated for a certain pixel at a time. However, a sequence of pixels can be simulated by varying the range, view angle, atmospheric condition, or the clutter level. The target consists of one or two subpixel surface elements, the remaining part of the pixels represents background. Multiple paths, e.g. sun-ground-target-sensor, can also be selected. An expert system, based upon the IDL language, provides user-friendly input menus, performs consistency checks, and submits the required MODTRAN and SENSAT runs. A sample case of the detection probability of a sub-pixel target in a marine cluttered background is discussed.