Overview of the HDL impulse synthetic aperture radar

Summary form only given. An impulse radar built on a railroad track on top of the main building at the US Army´s Harry Diamond Laboratories (HDL) facility in Adelphi, Maryland, is described. The radar operates over a ultrawide bandwidth of 50-1000 MHz and is fully polarimetric. Coherence is maintained across the aperture by a coherent-on-receive system. The pulse repetition interval is jittered by a code with a spike autocorrelation. The radar includes a 480 MFLOP array processor that is used to do pulse-to-pulse interference filtering followed by a backprojection focusing algorithm. Since the bandwidth of the radar is greater than that of real targets, both the range resolution and azimuthal resolution are constrained by the target scattering characteristics rather than the radar. Measurements to be carried out by the radar include clutter backscatter, foliage penetration loss, foliage penetration group delay, signatures of dispersive targets in the presence of clutter, and signatures of anisotropic targets in clutter.<>