Fast Approach to Estimate the Longest Axis in Coherence Region and Its Applications
Bai Lu①②,Cao Fang①,Hong Wen①
①National Key Laboratory of Microwave Imaging Techniques, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, China; ②Graduate University of Chinese Academy of Sciences, Beijing 100049, China
Abstract：The longest axis in coherence region, which gives the largest distance between any two coherences, is significant in forestry applications using coherence scattering model, because it reflects the linear variation of complex coherences with the polarization states. To improve the efficiency and accuracy of traversal search, a fast approach is proposed to estimate longest axis in this paper. It uses the line segment of the tangent points of the rectangle externally tangent to coherence region to get the initial estimation for the longest axis. Nest, it obtains the longest axis using the approximation technique. To improve forest height estimation, a forest parameter inversion technique using the longest axis is presented. Results of simulated data for pine forest show the fast approach consumes much less computation time and gives better estimations for the longest axis than traversal search method. Results also show that the introduction of longest axis in forest parameter inversion yields closer estimations to the true forest height.
白璐,曹芳,洪文. 相干区域长轴的快速估计方法及其应用[J]. 电子与信息学报, 2010, 32(3): 548-553 .
Bai Lu①②,Cao Fang①,Hong Wen①. Fast Approach to Estimate the Longest Axis in Coherence Region and Its Applications. , 2010, 32(3): 548-553 .
2010, Vol. 32 
