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Labanda, M.F., Jacob, M.M., Farrar, S., Raimondo, H.A., and Jones, W.L. (04-Dec-12)

The Microwave Radiometer (MWR), on board of SACD/Aquarius satellite, measures the surface brightness temperature TB at the top of the atmosphere in a frequency range sensitive to geophysical parameters over the ocean (surface wind speed, rain rate, water vapor, cloud liquid water and sea ice concentration). MWR is a push-broom 3 channel, Dicke radiometer, operating at K (23.8 GHz HPol) and Ka (36.5 GHz, H- & V-Pol) band. The instrument has 16 beams, 8 forward-looking 36.5 GHz and 8 aftlooking 23.8 GHz. The beams are arranged in a configuration with two incidence angles, one of 52 (4 odd beams) and one of 58 (4 even beams), for both forward and aftlooks. Since the first global TB images, there has been observed an anomalous recurrent effect, coined as Smear Effect. This effect is present in all push-broom beams and results in a “smearing” of Tb observations, that is more noticeable near high contrast areas, such as land/water crossings, rain events, and in the presence of clouds. After a detail analysis it was determined that the smear effect strongly affects the geophysical retrieval products. CONAE studied the effect, in a variety of cases, and developed a method to try to mitigate this smearing effect. The correction was applied to TB counts and with this data the retrievals was reprocessed. We present in this paper a comparison between the results obtained before and after the correction with noticeable improvement in MWR products, i. e., more realistic geophysical retrieval products. The improvement is demonstrated by both global and regional studies over land and ocean.