A system in accordance with the present invention determines signal attenuation for an electronic support measure receiver. The system includes a detection module for receiving electromagnetic signals from a surrounding environment and a processing module for chronologically segregating the electromagnetic signals into a plurality of dwells. The processing module controls the processing of the plurality of dwells. The processing module determines an analysis dwell from the plurality of dwells. The processing module computes a coarse attenuation for the analysis dwell. The processing module further computes a fine attenuation from the coarse attenuation and an offset table value.