Geolocation Method Study On Rotating, Range-gated, Fanbeam Scatterometer Data

Microwave scatterometer is an important instrument of the marinemonitoring,has the characteristics of all-time and all-weather work,play an importantrole in the marine and terrestrial detection.It is used for ocean surface wind field andsea ice monitoring in the ocean,and soil moisture or vegetation parameters.Thescatterometer geolocation is an important part of the scatterometer preprocess,isrelated to remote sensing data quality.Ground objects’ backscattering contain effectivemeasurement by geolocation.scatterometer geolocation has important significance forensure the quality of the scatterometer data.This paper analyzes work principle of fan beam rotation scanning scatterometerand the number of observations of the scanning beam on the ground point.The resultshows that the number of observations of most points can be four times,this isadvantaged to removal of wind retrieval fuzzy solution.Get a satellite track usingsatellite orbit parameters and SGP4model algorithm;have a RFSCAT scatterometersimulation according to antenna parameters and ways of working,as geolocationdata.In the paper,an improved patt94algorithm apply to RFSCAT simulation data forgeolocation,and verify the accuracy of algorithm using HY-2scatterometerdata.Geolocation relative accuracy is less than4×10-4degree.Therefore,the result isthat the accuracy of algorithm achieve expected goal,comply with the requirements ofpractical applications.Error sources of geolocation include satellite position error,satellite attitude errorand instrument pointing error.Theoretically discuss the impact of these errors ongeolocation result basing on the observation geometry of the antenna. Then these errors are joined in the geolocation algorithm,analyze the sensitivity of the algorithmfor these errors and the stability of the algorithm.The results showed that the satelliteattitude error and instrument pointing error are greater than the satellite position errorfor geolocation.Geolocation error research have some guiding significance forcontrolling error sources to improve geolocation accuracy.Finally,the paper proposespositioning accuracy of the geolocation algorithm by considering geolocation errorsources,the model accuracy and algorithm accuracy.