Mapping mountain meadow with high resolution and polarimetric SAR data

35th International Symposium on Remote Sensing of Environment

地球科学;生态环境科学

Tian, Bangsen^1 ; Li, Zhen^1 ; Xu, Juan^1,2 ; Fu, Sitao^1,2 ; Liu, Jiuli^3

Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing 100094, China^1

University of Chinese Academy of Sciences, Beijing, China^2

Beijing Institute of Spacecraft System Engineering, CAST, Beijing, China^3

关键词: Classification accuracy;    Image coordinates;    Land cover classification;    Monitoring capabilities;    Polarimetric SAR data;    Radiometric corrections;    Supervised classification;    Terrain correction;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/17/1/012076/pdf
DOI  :  10.1088/1755-1315/17/1/012076

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

This paper presents a method to map the large grassland in the eastern margin of the Tibetan Plateau with the high resolution polarimetric SAR (PolSAR) imagery. When PolSAR imagery is used for land cover classification, the brightness of a SAR image is affected by topography due to varying projection between ground and image coordinates. The objective of this paper is twofold: (1) we first extend the theory of SAR terrain correction to the polarimetric case, to utilize the entire available polarimetric signature, where correction is performed explicitly based on a matrix format like covariance matrix. (2) Next, the orthoectified PolSAR is applied to classify mountain meadow and investigate the potential of PolSAR in mapping grassland. In this paper, the gamma naught radiometric correction estimates the local illuminated area at each grid point in the radar geometry. Then, each element of the coherency matrix is divided by the local area to produce a polarimetric product. Secondly, the impact of radiometric correction upon classification accuracy is investigated. A supervised classification is performed on the orthorectified Radarsat-2 PolSAR to map the spatial distribution of meadow and evaluate monitoring capabilities of mountain meadow.