Typical Underlying Surface Albedo Product Authenticity Verification Method Of Research

The surface is an important parameter in climate and land surface processing model, it quantify the reflection of the solar radiant energy, can effective monitoring surface radiation energy exchange. Inversing albedo and validating the albedo products are the important case in quantitative remote sensing research, they are of great significance on monitoring the climate and the ecological environment change.In this paper, The study areas are Surfrad’s Desert Rock, NV (Desert), Goodwin Creek, MS (Agriculture), Greenland’s JAR1and JAR2(ice) and China flux nets of ChangBai mountain (broadleaf forests), XiShuangBanNa (evergreen broad-leaved forest), DangXiong (grass or grain this plant). This paper first using ETM+image inversing albedo, and then using ETM+as the middle scale, up-scaling to the some scale as the MODIS albedo products, and last validating the MODIS albedo products verification. The research content and conclusions include:(1) Combined with surface coverage type change of season, distinguishing between ice and snow and the snow free land surface, choosing the right model in different surface type. To do this can effectively reduce the error in the inversion, through comparing the ground site measured values and the ETM+inversion albedo, found the precision of the inversion albedo meet the requirement.(2) Using the variance function and its related parameters to analyze the spatial variation and scale effect on the several typical types in the summer vegetation growing season and the winter vegetation dormancy season. According to the analysis of variance of different land surface types, getting the size of the homogeneous units in each land surface type, then Using the Point Spread Function up-scaling the ETM+reflectance to the size of the homogeneous unit, and then inversing the albedo. After reducing neighbor influence, up-scaling the ETM+albedo to the MODIS pixel size.(3) Study found that, in the short term of the solar altitude angles change have great influence of the albedo, because ETM+crossed the solar altitude angles and MODIS products (local at noon) solar altitude angles generally does not agree, so according to the solar altitude angles and the land surface measurement albedo setting up the statistical model of them. At last corrected the ETM+albedo to the local at noon solar altitude angle. It can effectively reduce the validation errors.(4) Combined several land cover types ground measurement and the ETM+albedo to validate the MODIS albedo, Analyse the error from the time sequence or space regional scale validation. The error may come from the "nuclears" which are used to Simulate Surface scattering and solar altitude angles.