Study Of Snow Depth Based On Multi-source Data About Aletai Area

The study of the depth of accumulated snow is very significant, because it is oneof the main elements of the cryosphere. Microwave remote sensing is one of themethods to study snow depth. The snow depth inverted by Microwave Imager datafrom FY-3meteorological satellite (FY-3) is widely accepted as the best product atpresent, which is credible in monitoring snow depth on a large scale, but data derivedfrom its specific application in the Altay geographical environment turned out to behigher than measured data. Taking this as the starting point, based on the snowservice project of Altay region by the National Meteorological Bureau of Urumqisatellite ground station, we used real-time multi-source remote sensing data andmeteorological station observations to propose a snow depth inversion model. Thismodel is significant in improving accuracy of snow depth data inversion from FY-3in Altay region and in snow parameter inversion in China.With the aim of more accurate measure of snow depth in Altay region, thispaper combined three types of data from2010winter to2013winter (November toMarch of the next year):①IMS data from the United States interactive ice mappingsystem (Interactive Snow and Ice Mapping System);②s now depth data inverted byMicrowave Imager from FY-3meteorological satellite (FY-3);③11284measureddaytime snow depth data from Altay region and surrounding31groundmeteorological stations, to study real-time snow depth monitoring in Altay region.The main research contents of this paper are as follows:(1)Data preprocessing: we conducted snow depth temperature conversion,longitude-latitude projection, resampling and format conversion for microwaveremote sensing from2010winter--2013winter (November to March of the nextyear), and extracted, resampled and converted IMS snow cover data of our researcharea, and also extracted, converted measured snow depth, preparing for theexperiment.(2)Procedures: snow depth inversion Extracting microwave snow depth datacorresponding to the measured station position from2010winter--2013winter(November to March of the next year), we calculate corresponding depth increments,then the Kriging method was used to determine the increments with spatial continuity,and then used revised snow depth data and IMS snow cover data to correct precisionand to control quality of microwave snow depth data, making snow depth of Altayregion close to actual values. Last, Kriging method was used again for spatial interpolation of corrected snow depth data, resulting in corrected snow depth datawith spatial continuity in Altay region.(3)Verification of experimental results: by comparing between snow depth datafrom our experiment and that measured from field investigation from January7,2013to January15,2013, we can find that the gaps between data before correctioncompared with measured data and that after correction compared with measured datahave been narrowed. The gap of Qinghe County had dropped from14cm to2cm,Fuyun County from19cm to4cm, Altay City from22cm to2cm while Buerqin from12cm to3cm, which indicates that methods proposed by this paper can produce snowdepth values closer to actual values.(4)The development of system: taking Matlab2012as the development language,we developed a snow product application system and data process interfaces in Altayregion, with entry including snow depth data, measured snow depth data and IMSsnow cover data, and snow depth map product as exit, which is presently on a testrun in Data service department, Urumqi meteorological satellite ground station.