Effects of spatial distribution of soil parameters on soil moisture retrieval from passive microwave remote sensing  

作　　者：ZHANG Tao ZHANG LiXin JIANG LingMei ZHAO ShaoJie ZHAO TianJie LI YunQing 

机构地区：[1]State Key Laboratory of Remote Sensing Science,Jointly Sponsored by Beijing Normal University and the Institute of Remote Sensing Applications of Chinese Academy of Sciences,Beijing 100875,China [2]School of Geography and Remote Sensing Science,Beijing Normal University,Beijing 100875,China

出　　处：《Science China Earth Sciences》2012年第8期1313-1322,共10页中国科学（地球科学英文版）

基　　金：supported by National Natural Science Foun-dation of China (Grant No.41030534);National Basic Research Program of China (Grant No. 2007CB714403);The European Commission Under FP7 Topic ENV.2007.4.1.4.2 "Improving Observing Systems for Water Resource Management"

摘　　要：In this paper,we studied the effect of spatial distribution of soil parameters on passive soil moisture retrieval at pixel scale.First,we evaluated the forward microwave emission model and soil moisture retrieval algorithm accuracy through the observa-tion of field experiments.Then,we used soil parameters in different spatial distribution patterns,including random,normal,and uniform distribution,to determine the different levels of heterogeneity on soil moisture retrieval,in order to seek the rela-tionship between heterogeneity and soil moisture retrieval error.Finally,we conducted a controlled heterogeneity effect ex-periment measurements using a Truck-mounted Multi-frequency Radiometer(TMMR) to validate our simulation results.This work has proved that the soil moisture retrieval algorithm had a high accuracy(RMSE=0.049 cm3 cm 3) and can satisfy the need of this research.The simulation brightness temperatures match well with observations,with RMSE=9.89 K.At passive microwave remote sensing pixel scale,soil parameters with different spatial distribution patterns could have different levels of error on soil moisture estimation.Overall,we found that soil moisture with a random distribution in a satellite pixel scale can cause the largest error,with a normal distribution being the second,and a uniform distribution the least due to the smallest het-erogeneity.In this paper, we studied the effect of spatial distribution of soil parameters on passive soil moisture retrieval at pixel scale. First, we evaluated the forward microwave emission model and soil moisture retrieval algorithm accuracy through the observa- tion of field experiments. Then, we used soil parameters in different spatial distribution patterns, including random, normal, and uniform distribution, to determine the different levels of heterogeneity on soil moisture retrieval, in order to seek the rela- tionship between heterogeneity and soil moisture retrieval error. Finally, we conducted a controlled heterogeneity effect ex- periment measurements using a Truck-mounted Multi-frequency Radiometer （TMMR） to validate our simulation results. This work has proved that the soil moisture retrieval algorithm had a high accuracy （RMSE=0,049 cm^3 cm^-3） and can satisfy the need of this research. The simulation brightness temperatures match well with observations, with RMSE=9.89 K. At passive microwave remote sensing pixel scale, soil parameters with different spatial distribution patterns could have different levels of error on soil moisture estimation. Overall, we found that soil moisture with a random distribution in a satellite pixel scale can cause the largest error, with a normal distribution being the second, and a uniform distribution the least due to the smallest het- erogeneity.

关 键 词：bare soil HETEROGENEITY spatial distribution passive microwave remote sensing soil moisture 

分 类 号：S152.7[农业科学—土壤学] TP722.6[农业科学—农业基础科学]