Surface wind measurements by radiometer-polarimeters in frame of Russia airspace programs

Radiometric near surface wind measurements are founded on polarization anisotropy of the thermal microwave emission from ocean. Physical reasons for such an anisotropy for nadir observations were revealed in SRT RAS, in 1978-1979 first theoretically and then experimentally (the so-called “critical phenomena”). The method for wind speed and direction measurements developed in the Space Research Institute is based on nadir radiometer-polarimeter observations. This method provides the accuracy of the wind speed measurements better than 2 m/s, or twice as high if parameters of lower atmosphere stability are known. Nadir-looking surface wind measurements demonstrated their efficiency during long-term Russian experiments in the Barents Sea, in the North-West Pacific (near Kamchatka and Sakhalin) and during the Joint US-Russia Experiment (JUSREX-92) in the Atlantic, near the New York coast. An experimental airborne system included a polarimetric radiometer at 13.3; 20.0, and 35 GHz and radiometers at 1.6; 3.6; 5.0; 22 and 37 GHz. A polarimetric nadir-looking radiometer IKAR-N (frequency 13.33 GHz) developed by SKB of IRE RAS is to be launched on the MIR-PRIRODA module in 1996. The multifrequency and multibeam radiometric-polarimetric system PARK was developed in SRI RAS for another spacecraft of the ALMAZ series. Such a system at frequencies 5.0; 13.3; 20 and 35 GHz is supposed to form 8-16 beams using light low-loss metal-ceramic Luneberg lenses. The lenses provide panoramic images of the sea surface without scanning. Sensitivity of the PARK system within a resolution element is 3-4 times higher that of the scanning system