Electromagnetic forward-scattering measurements over a known, controlled sea surface at grazing

A series of low-angle radar measurements were conducted over a large wave pool capable of producing a wide range of scaled sea conditions. The X-band (8-12 GHz) measurements were performed for 1°, 3°, and 5° look down angles (LDAs) for the HH and VV polarizations. The roughened water simulated a one-dimensional 1/10th-scale Pierson-Moskowitz surface at sea states 0, 3, and 5. The wave profiles were detailed using both ultrasonic point detectors and a laser sheeting technique capable of measuring a cross section of the sea. The compiled data represent the first forward-scattering measurement 1) preformed under a variety of controlled conditions for low grazing angles and 2) with detail profiling of the wave structure syncronized with the radar. Presented are the experimental setup with calibration methodology, measurement conditions, and selected radio-frequency forward-scattering (HH polarization) results for the 5° LDA for sea state 0, 3, and 5 sea conditions.