1. 北京师范大学地理学与遥感科学学院，遥感与地理信息系统研究中心，遥感科学国家重点实验室，环境遥感与数字城市北京市重点实验室，北京 100875 2. Geography and Environment Dept. of Boston University, Center for Remote Sensing, Boston, MA., USA 02215
The Research on Bidirectional Reflectance Computer Simulation of Forest Canopy at Pixel Scale
SONG Jin-ling1, WANG Jin-di1, SHUAI Yan-min1, 2, XIAO Zhi-qiang1
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. Geography and Environment Dept. of Boston University, Center for Remote Sensing Boston, MA 02215, USA
Abstract：Computer simulation is based on computer graphics to generate the realistic 3D structure scene of vegetation, and to simulate the canopy regime using radiosity method. In the present paper, the authors expand the computer simulation model to simulate forest canopy bidirectional reflectance at pixel scale. But usually, the trees are complex structures, which are tall and have many branches. So there is almost a need for hundreds of thousands or even millions of facets to built up the realistic structure scene for the forest. It is difficult for the radiosity method to compute so many facets. In order to make the radiosity method to simulate the forest scene at pixel scale, in the authors’ research, the authors proposed one idea to simplify the structure of forest crowns, and abstract the crowns to ellipsoids. And based on the optical characteristics of the tree component and the characteristics of the internal energy transmission of photon in real crown, the authors valued the optical characteristics of ellipsoid surface facets. In the computer simulation of the forest, with the idea of geometrical optics model, the gap model is considered to get the forest canopy bidirectional reflectance at pixel scale. Comparing the computer simulation results with the GOMS model, and Multi-angle Imaging SpectroRadiometer (MISR) multi-angle remote sensing data, the simulation results are in agreement with the GOMS simulation result and MISR BRF. But there are also some problems to be solved. So the authors can conclude that the study has important value for the application of multi-angle remote sensing and the inversion of vegetation canopy structure parameters.
宋金玲1,王锦地1,帅艳民1, 2,肖志强1 . 像元尺度林地冠层二向反射特性的模拟研究[J]. 光谱学与光谱分析, 2009, 29(08): 2141-2147.
SONG Jin-ling1, WANG Jin-di1, SHUAI Yan-min1, 2, XIAO Zhi-qiang1 . The Research on Bidirectional Reflectance Computer Simulation of Forest Canopy at Pixel Scale. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2009, 29(08): 2141-2147.
[1] CHEN Xin-fang, CHEN Jing-ming, LIU Yu-hong, et al(陈新芳, 陈镜明, 刘玉虹, 等). Chinese Journal of Ecology(生态学杂志), 2005, 24(9): 1074. [2] SONG Jin-ling, WANG Jin-di, LIU Xiao-qing(宋金玲，王锦地，刘小青). Journal of Remote Sensing(遥感学报), 2007, 11(2): 229. [3] LI Xiao-wen, WANG Ji-di(李小文，王锦地). Models of Vegetation Optics Remote Sending and Parameterize of Vegetation Geometry(植被光学遥感模型与植被结构参数化). Beijing: Science Press(北京: 科学出版社), 1995. [4] PENG Qun-sheng, BAO Hu-jun, JIN Xiao-gang(彭群生，鲍虎军，金小刚). The Algorithm Based on Computer Realistic Graphics(计算机真实感图形的算法基础). Beijing: Science Press(北京: 科学出版社), 2003. [5] Gerard F F, North P R J. Remote Sensing of Environment, 1997, 62: 46. [6] Li Xiaowen, Strahler A H. IEEE Transactions on Geoscience and Remote Sensing, 1988, 26(2): 161. [7] Li Xiaowen, Strahler A H. IEEE Transactions on Geoscience and Remote Sensing, 1992, 30(2): 276. [8] ZHU Qi-jiang, FAN Yun-hua, LIU Lai-fu, et al(朱启疆, 范韵华, 刘来福, 等). Remote Sensing of Environment China(环境遥感), 1995, 10(1): 70. [9] WANG Jin-di, LI Xiao-wen, XIANG Yue-qin(王锦地， 李小文，项月琴). Science in China Series E(中国科学, E辑), 1997, 27(5): 430. [10] Shunlin Liang, Strahler A H. IEEE Transactions on Geoscience and Remote Sensing, 1993, 31: 1081. [11] SONG Jin-ling, WANG Jin-di, LIU Xiao-qing, et al(宋金玲，王锦地，刘小青, 等). Journal of Remote Sensing(遥感学报), 2007, 11(5): 670. [12] Ni Wenge, Li Xiaowen, Woodcock Curtis E, et al. IEEE Transaction on Geoscience and Remote Sensing, 1999, 37(2): 987. [13] Qin Wenhan, Gerstl Siegfried A W. Remote Sensing of Envronment, 2000, 74: 145. [14] ZHANG Hong-ming(张宏名). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 1994, 14(5): 25. [15] Smolander Sampo, Stenberg Pauline. Remote Sensing of Envronment, 2005, 94: 355.
