Land Surface Albedo Remote Sensing Products Validation Over Rugged Terrain

Author:Lin Xingwen

Supervisor:Willow admire fire, wen Jianguang


Degree Year:2018





The quantitative remote sensing products validation is an essential process before the products’ application to scientific research and environmental monitoring.The remote sensing products validation can be defined by the CEOS as assessing the quality of land surface remote sensing products independently with reference data prior to utilization.Albedo products validation are at the stage three which defined by CEOS.It can be described as the albedo products has been compared with the ground-based measurements with long time series recored at the sites with representativeness over the global scale.However,the validation activities are usually conducted at the flat terrain.The rugged terrain surface covers about 24 percent of the land surface in the global scale and covers 2/3 percent of the land surface in China.To assess the land surface remote sensing products comprehensively,the accuracy and uncertainty of the products over rugged terrain need to be evaluated before wide application.The issue for the validation of land surface remote sensing products over rugged terrain is the scale effects between the reference measurements and coarse scale products,which is caused by the complex topography.And the validation methods used to access the land surface remote sensing products over flat terrain maybe not very suitable to deal with the validation activities over rugged terrain.This research proposed a validation strategy for validation the land surface remote sensing products over rugged terrain.The land surface albedo products were selected as the products to be validated and another parameter can follow the validation processes over rugged terrain.Three key issues are introduced over this paper,including the quality assessment of reference validation data;the retrieval of fine scale albedo over rugged terrain;and the scale upscaling from fine scale reference measurements to coarse pixel scale.This paper makes some attempts to study the remote sensing products validation over the rugged surface.And a web-based validation system which coupled with the quality assessment methods of reference data and the suitable validation methods was accomplished in this paper.Generally speaking,the MCD43A3 C6 products showed the higher uncertainty over rugged terrain than that at flat terrain,with the RMSE of 0.035,and the relative RMSE of 21%.And the uncertainty of MCD43A3 C6 products showed an increasing trend following the increase of the slope of the terrain,with the RMSE larger than 0.044 at the sites of which the slope is large than 10 degree.The validation results of GLASS albedo products showed the similar validation results than MCD43A3 C6 products with the RMSE of 0.035.