Acta Geodaetica et Cartographica Sinica ›› 2017, Vol. 46 ›› Issue (11): 1868-1879.doi: 10.11947/j.AGCS.2017.20170122

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Vegetation Height Inversion Method with Three-layer Model by Fusing the Ascending and Descending PolInSAR Data

SHEN Peng1, WANG Changcheng1,2, ZHU Jianjun1, GAO Han1, FU Haiqiang1, XIE Qinghua1, WANG Sai1, HE Shuaishuai1   

  1. 1. School of Geosciences and Info-Physics, Central South University, Changsha 410083, China;
    2. Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring(Central South University), Ministry of Education, Changsha 410083, China
  • Received:2017-03-22 Revised:2017-09-08 Online:2017-11-20 Published:2017-12-05
  • Supported by:

    The National Natural Science Foundation of China (Nos. 41531068 41371335 41671356) The National Natural Science Foundation of Hunan Province of China (No. 2016JJ2141) The Planned Science and Technology Project of Hunan Province, China (No. 2016SK2003) PA-SB ESA EO Project Campaign (No. 14655) Innovation Foundation for Postgraduate of Central South University (No. 2017zzts549)

Abstract:

The acquisition of forest parameters can not only estimate the surface biomass and underlying topography,but also contribute to the study of global carbon cycle and global climate change.Vegetation parameter inversion algorithm with polarimetric interferometric SAR (PolInSAR) is generally based on the two-layer RVoG(random volume over ground) model.However,when the actual vegetation has three-layer structure of canopy,trunk layer and surface layer,the vegetation parameters inversion accuracy will decrease.As the vertical effective wave number difference between the near and far range in the case of airborne SAR system is large,it will bring the system error to the final inversion results.To solve these two problems,this paper proposes an algorithm of three-layer vegetation parameters inversion by fusing the ascending and descending PolInSAR data.The proposed method uses the three-layer RVoG model to correct scattering process of radar echo in vegetation.Then it combines the ascending and descending PolInSAR datasets to weaken the system errors; Finally,we use the non-linear iteration adjustment for tree height inversion.In order to validate the proposed algorithm,two ascending and two descending P-band full polarization SAR data acquired by ESAR airborne platform under the German space agency (DLR) BioSAR 2008 campaign are utilized and other three inversion strategies are used for comparison and analysis.The results prove the correctness of the three vegetation model,and the proposed method reduces the system error caused by the vertical effective wave number and improves the precision of tree height inversion.

Key words: random volume over ground, vegetation height, three-layer vegetation model, three-stage algorithm, ascending and descending, vertical wave number

CLC Number: