Correlation of Target Transfer Functions and range profiles as a function of aspect angle and resolution

An experimental rig was constructed in order to investigate the variation of the radar signature of a 1:32 scale model tank with changes in aspect. By illuminating the target with a wideband stepped frequency waveform, a high range resolution profile was obtained with an associated frequency spectrum that approximated the target transfer function (TTF). It was found that both TTFs and range profiles de- correlated within a 1deg change in target azimuth, more rapidly than previously thought. It was also found that coarser range profiles correlated better than finer ones, but at the loss of a significant amount of distinctive target information. These results have implications for the size of the reference library employed in correlation-matching within the field of non-cooperative target recognition, and also for the number of different waveforms required to enable matched illumination of a target from all aspects.