Study On The Retrieval Of Aerosol Optical Depth Based On HJ-1Satellite

The aerosol is not only an important parameter in researching the global climate,but also it is the important physical quantities in characterized of atmospheric turbidity.The Aerosol has a very important influence in human life and global change. Therefore,it has a very important practical significance in study radiation characteristics ofaerosol. Our country has launched HJ-1satellite, which is a forecastconstellation,specially used for monitoring environment and disaster. This paper isbased on the wide coverage and multi-spectral CCD camera data from HJ-1satellite toresearch the inversion method of AOD.Aerosol optical depth(AOD) has a good indication effect in research theatmospheric pollution of local area. So we can have a general idea of air pollution inNingbo area by the result of retrieval aerosols optical depth in this area.In order to validate HJ-1satellite’s applicability in Ningbo area and understand theatmospheric pollution condition in this place, we use the modified Dark DenseVegetation(DDV) method to retrieve the AOD in this text. Because of the very matureoperational inversion process in retrieval aerosols optical darkness through the DDValgorithm by MODIS images data. In this paper there are some improvement when weuse this operational MODIS AOD retrival process,then we can retrivial the aerosolsoptical depth by HJ-1satellite.In the process of retrieval the AOD, we used a Look Up Table (LUT) which wasbuilt based on atmospheric radiation transmission model of6S. In order to realize thewhole inversion processFirstly, we preprocessed the original remote sensing image data. Then the DDVwas recognized by NDVI algorithm. Finally we can determine the reflectivity function.For comparison and validation the AOD retrieved from HJ-1satellite, two methodwas used, One is using other AOD retrieved from MODIS to compare with this methodin space, the other method is by the sun photometer data in point. Because the MODISaerosol product has greatly different spatial scales with HJ-1AOD, we used MODISL1B data to get1km resolution AOD to compare with HJ-1inversion results in space. As a result, the HJ-1retrieval results have good correlation with MODIS result, and thecorrelation coefficient is0.8037.Besides, this paper used the CE-318data fromAERONET to validate the AOD inversed from HJ-1.The result shows AOD retrievalvalues have high consistency with sun photometer observations. The correlationcoefficient is0.89.So we conclude that,HJ-1satellite has a good application prospectand development potential in monitoring urban environment aerosol pollution.