Abstract: A method including collecting physical measurement data from a sensor. The physical measurement data is converted to radiance data. The radiance data includes a plurality of radiance data points. A detection score is generated by processing the radiance data using a discriminant function. The detection score includes a plurality of detection score points corresponding to the plurality of radiance data points. The discriminant function is derived by a fusion technique using a linear log likelihood ratio principle. A detection map is generated by applying a threshold to the detection score. The detection map includes a plurality of detection map points corresponding to the plurality of radiance data points, each detection map point of the plurality of detection map points includes one of a target-indicating value and a clutter-indicating value. A presence or an absence of a target is determined from the detection map.