S.D. Blunt and K. Gerlach Radar Division Introduction: Pulse compression enables a radar to achieve the high range resolution of a short pulse without the need for high peak transmit power via the transmission of a modulated long pulse

simulation, computing, and modeling 2005 NRL Review Adaptive Radar Pulse Compression nearby large targets. In so doing, RMMSE suppresses the range sidelobes induced by the nearby large targets so that the true complex amplitude of the particular range cell can more accurately be estimated. Furthermore, the refi ned range cell estimates obtained from applying RMMSE can themselves be used as more accurate a priori knowledge with which to repeat RMMSE and further improve the estimation accuracy. It has been found via extensive numerical simulation that 3 to 4 stages of range cell estimation (inclusive of the initial matched-fi ltering operation) are suffi cient to suppress the sidelobes into the noise and thereby unmask any small targets. Th e process of alternating estimation between the range cells and the receive fi lters is denoted as the Adaptive Pulse Compression (APC) algorithm. As an example, consider Fig. 2 in which three stages of the APC algorithm is able to uncover the small target that was previously masked by using the matched fi lter. Furthermore, as an example of a stressing scenario, Fig. 3 illustrates the case of several densely spaced targets with highly disparate power levels such as might occur for a convoy with a Ground Moving Target Indicator (GMTI) radar, an airborne formation, or as a result of synthetic aperture radar (SAR) clutter imaging. In this scenario the matched fi lter reveals only the largest targets and masks the smaller ones. In comparison, the APC algorithm enables the detection of even the very small targets by mitigating the range sidelobes from the large targets.