Algorithm Of Microwave Remote Sensing Of Ocean Salinity And Impact Factor Analysis

Sea surface salinity is an important parameter in studying ocean circulation and the effects of ocean on the global climate, but has not achieved the satellite remote sensing. Salinity remote sensing has become an important research field in marine remote sensing. The main task of this paper is to study the retrieval error of salinity retrieval algorithm in terms of ocean salinity microwave remote sensing, analyze the influencing factors of salinity remote sensing and determine the correction method.In this paper, the retrieval algorithm of salinity remote sensing is divided into two kinds: single-band algorithm and dual-band algorithm. Dual-band algorithms includes binary polynomial fit algorithm and semi-analytical retrieval algorithm, both of which are using L/S dual-band brightnesses. The original single-band algorithm of retrieval salinity and temperature is using brightness of L-band and sea surface temperature, and the new algorithm proposed in this paper is using perpendicularity-polarization brightness and horizontal-polarization brightness of L-band. By processing the ideal data and the measured data, the algorithm mentioned above are compared and the results show that semi-analytical retrieval algorithm has the highest salinity retrieval precision. Incidence and polarization also affect the retrieval precision. The salinity retrieval precision is the highest when L-band using dual-polarization, using perpendicularity-polarization is second best and using horizontal-polarization is the worst. Meanwhile, the polarization of S-band also influences the precision of salinity retrieval. The smaller the incidence is, the smaller the differences between various polarization modes are. In this paper, the influencing factors on the salinity remote sensing are summarized in three aspects: outer space, sea and atmosphere. Besides, we have established modified formula and each influencing factor is analyzed and calculated. Finally, using the measured data of airborne remote sensing and marine surface in northern yellow sea obtained on September 10, 2005, salinity retrieval are carried out with dua-band algorithm and single-band algorithm of simi-analytical retrieval algorithm, repectively. The measured experiment data are modified with modified formula of brightness, and then compared carefully. The results show that the combination of dual-band and dual-polarization is the best choice for salinity microwave remote sensing retrieval and the salinity retrieval accuracy is 0.5. Single-band algorithm of using dual-polarization brightness is also feasible, but the precision is worse than that of the dual-band algorithm. The inversion precision when considering the influencing factors is highest than that when not considering these factors.