Model-Based Analysis of the Influence of Forest Structures on the Scattering Phase Center at L-Band
作者:Ni, WJ (Ni, Wenjian)[ 1,2 ] ; Sun, GQ (Sun, Guoqing)[ 3 ] ; Ranson, KJ (Ranson, Kenneth Jon)[ 4 ] ; Zhang, ZY (Zhang, Zhiyu)[ 2,1 ] ; He, YT (He, Yating)[ 5 ] ; Huang, WL (Huang, Wenli)[ 3 ] ; Guo, ZF (Guo, Zhifeng)[ 2,1 ]
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
卷: 52  期: 7  页: 3937-3946
DOI: 10.1109/TGRS.2013.2278171
出版年: JUL 2014

摘要
The estimation of forest biomass from synthetic aperture radar (SAR) data is limited by the lack of forest structure information. Interferometric synthetic aperture radar (InSAR) provides a means for the extraction of forest structure. The crucial issue in InSAR application is to parameterize forest structure and to link the parameter with InSAR observations. Model-based analysis enables exploring the theoretical linkages between InSAR observations and forest structure free from temporal decorrelation effects. In this paper, a semicoherent model (SCSR) was first developed and verified. A series of simulations at L-band was then made for both homogeneous and heterogeneous forests generated from a forest growth model. The forest structure was parameterized by four height indices. Aside from the height of scattering phase center (HSPC), the depth of scattering phase center (DSPC) was also proposed to characterize the scattering phase center of InSAR. The results showed that the behavior of homogeneous forest on InSAR data was quite different from that of heterogeneous forest. Special care was needed when the retrieval algorithms of forest biomass developed on a homogeneous forest were applied to a heterogeneous forest. Crown size-weighted height (CWH) and Lorey's height were correlated with the HSPC at all polarizations and with the DSPC at copolarization in both cases of homogeneous and heterogeneous forests. These findings indicated that CWH could be an alternative biomass indicator of the Lorey's height for biomass estimation, which can be derived from the combination of InSAR data and the elevation of the forest canopy top from lidar or high-resolution stereo images.

通讯作者地址: Ni, WJ (通讯作者)
Univ Maryland, Dept Geog Sci, College Pk, MD 20742 USA.
地址:
[ 1 ] Chinese Acad Sci, Inst Remote Sensing & Digital Earth, State Key Lab Remote Sensing Sci, Beijing 100101, Peoples R China
[ 2 ] Beijing Normal Univ, Beijing 100101, Peoples R China
[ 3 ] Univ Maryland, Dept Geog Sci, College Pk, MD 20742 USA
[ 4 ] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA
[ 5 ] Chinese Acad Agr Sci, Inst Agr Resources & Reg Planning, Beijing 100081, Peoples R China