数字高程模型(digital elevation model, DEM)是重要的地理信息,合成孔径雷达(synthetic aperture radar, SAR)是提取数字高程模型的有效手段之一。本文以浙江衢山岛部分地区为研究区,利用2013年11月27日的Radarsat-2四极化精细工作模式极化SAR数据计算了研究区方位向两相邻分辨单元之间的极化方位角偏移量,从极化方位角偏移量提取了方位向坡度信息,得到了研究区地形的高程数据,并利用实测数据对提取的DEM信息进行了精度检验。结果表明,在海岸带及近海岛礁区域,单景全极化雷达DEM测量是可行的,计算结果的平均相对误差为20%,造成误差的主要原因是海面杂波造成的起算面的改变以及植被的树枝叶层造成方位角的变化导致的高程计算偏差。
Abstract
As Digital elevation model is an important geographic information, SAR(synthetic aperture radar) is one of the most effective means in digital elevation model extracting. Use Radarsat-2 fine Quad-polarization mode data (November 27, 2013)over Qushandao in Zhejiang province to figure out the polarization azimuth offset between two adjacent resolution cells, and then extract the gradient information and terrain elevation. Finally, test the accuracy of the digital elevation model by the measured data, whose average relative error turn out to be 20%,and the results showed that the main causes of errors is the change of the terrain basement caused by the sea clutter and the elevation deviation caused by the leaves and boughs of the vegetative cover.
关键词
数字高程模型 /
合成孔径雷达 /
全极化 /
衢山岛
Key words
DEM /
SAR /
full-polarization /
Qushandao
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] ZHANG Hong, YE Xi, WANG Chao, et al. The processing and applications of high resolution SAR images with object-based image analysis[J]. Journal of Image and Graphics,2014,19(3):344-357.
张红,叶曦,王超,等.面向对象的高分辨率SAR图像处理及应用[J].中国图象图形学报,2014,19(3):344-357.
[2] SCHULER D L, LEE J S, GRANDI D. Measurement of topography using polarimetric SAR images[J]. IEEE Trans on Geoscience and Remote sensing,1996,34(5):1 266-1 277.
[3] CHEN Xi, WANG Chao, ZHANG Hong. DEM Generation combining SAR polarimetry and Shape-From-Shading techniques[J]. IEEE Geoscience and Remote sensing,2009,6(1):28-32.
[4] GOODENOUGH D G,CHEN Hao,DYK A. Evaluation of Convair-580 and simulated Radarsat-2, polarimetric SAR for forest change detection[C]//Geoscience and Remote Sensing Symposium, IGARSS 2006. IEEE International Conference,2006:1 788-1 791.
[5] DING Qiong, LIU Guo-xiang, CAI Guo-lin, et al. Analysis of the correlation between the InSAR DEM accuracy and topographic features[J]. Science of Surveying and Mapping,2009,34(1):147-148.
丁琼,刘国祥,蔡国林,等.InSAR DEM精度与地形特征的关系分析[J].测绘科学,2009,34(1):147-148.
[6] LIANG Huai-ning, WANG Jian-guo, HUANG Shun-ji. Polarmetric synthetic aperture radar(SAR) three dimensional imaging[J]. Journal of Electronics and Information Technology,2002,24(5):584-590.
梁淮宁,王建国,黄顺吉.快速搜索算法与极化合成孔径雷达三维成像[J].电子与信息学报,2002,24(5):584-590.
[7] CHEN Qiang, SUN Wen-feng, JIANG Jing. An approximate estimation of radar polarization orientation angle by terrain slopes[J]. Journal of Air Force Radar Academy,2005,19(3):8-10.
陈强,孙文峰,江晶.用于地面坡度测量的极化SAR方位角近似估计方法[J].空军雷达学院学报,2005,19(3):8-10.
[8] SCHULER D L, KASILLINGAM D. Polarimetric SAR Measurements of slope distribution and coherence changes due to internal waves and currents fronts[J]. Processing of International Geoscience and Remote Sensing Symposium,2002,1(24-28):638-640.
[9] SCHULER D L, JANSEN R W, KASILLINGAM D. Polarisation orientation angle measurements of ocean internal waves and current fronts using polarimetric SAR radar [J]. IEEE Proceedings-Sonar and Navigation,2003,150(3):135-143.
[10] ZHAO Xian-bin, YAN Wei, KONG Yi, et al. Theoretical research and experimental verification for ocean surface wind vector retrieval from airborne C-band fully polarimetric SAR[J]. Acta Phys Sin,2013,62(13):1-12.
赵现斌,严卫,孔毅,等.机载C波段全极化SAR海面风矢量反演理论研究及实验验证[J].物理学报,2013,62(13):1-12.
[11] LIANG Huai-ning. Study on measurement topography using polarization SAR images[D]. Chengdu: University of Electronic Science and Technology of China,2001.
梁淮宁.全极化SAR地形高度测量技术研究[D].成都:电子科技大学,2001.
[12] CHEN Xi, ZHANG Hong, WANG Chao, et al. Estimation of the polarization orientation angle shifts induced by terrain slopes[J]. Remote Sensing Technology And Application,2007,22(1):59-65.
陈曦,张红,王超,等.由地形坡度引起的极化方位角偏移的估计[J].遥感技术与应用,2007,22(1):59-65.
[13] LIU Wen-xiang ,ZHANG Ji-xian ,HUANG Guo-man, et al. Application of terrain radiometric correction in polarimetric SAR imagery classification[J]. Science of Surveying and Mapping,2014,39(3):98-102.
刘文祥,张继贤,黄国满,等.地形辐射校正在极化SAR影像分类中的应用[J].测绘科学,2014,39(3):98-102.
[14] QIU Chun-ping, WANG Jian. On Method of Extraction from SAR imagery[J]. Science of Surveying and Mapping,2006,6(1):6-10.
仇春平,王坚.从SAR影像提取DEM的方法研究[J].测绘通报,2006,6(1):6-10.
基金
国土资源部公益性行业科研专项项目资助(201211009);国家级大学生创新活动项目资助(31015201346)