Aerosol Optical Thickness Retr ieving Over Br ight Sur face: Progr ess and Prospect
高反射率地区气溶胶光学厚度遥感反演:现状及展望

It is a great challenge to retrieve aerosol optical thickness over bright surface from remotely sensed data,because it is very difficult to estimate the reflectance of the complicated surface accurately,and the radiance is not sensitive to the aerosol change when the surface reflectance is high.To overcome the difficulties of aerosol optical thickness retrieving in the bright areas,many methods were provided.We introduced some significant methods: 1) contrast reduction algorithm.This method applied in a sequence of satellite images which contain a clear image;2) high contrast surfaces algorithm.This method can retrieve aerosol optical thickness from two closely located,high contrast surfaces;3) two or more sensors cooperation method,which can retrieve aerosol optical thickness together with surface reflectance;4) methods which are based on surface reflectance database/model,which need to ascertain the surface reflectance accurately.We analyzed the advantages and disadvantages of each method.At last,we provided the prospect of the aerosol optical thickness deriving over bright surface.The construction of surface reflectance database and the development of the BRDF model make the surface reflectance more accurate,the increasing aerosol measuring stations advance our quantitative understanding of aerosol characteristics,and the design of many new satellite sensors which can derive the aerosol optical thickness becomes more perfect.All of the above factors can help aerosol optical thickness retrieving a lot.