基于FY-3的格陵兰岛冰盖表面冻融探测方法研究

摘要

格陵兰岛的冰盖对全球气候有着极为重要的意义,冰盖的冻融情况可直观展示北极地区的气候变化状况.利用我国FY-3气象卫星的微波成像仪(Microwave Radiation Imager,MWRI)数据,基于增加干湿雪差异性的交叉极化比率(Cross-Polarized Gradient Ratio,XPGR)算法,通过支持向量机(Support Vector Machine,SVM)的超平面进行格陵兰岛冰盖表面冻融探测,与已有的阈值方法相比,理论上精度较高.与微波辐射计(Special Sensor Microwave Image,SSM/I)(阈值为-0.025)的数据结果进行对比验证,结果表明:XPGR结合SVM的格陵兰岛冰盖表面冻融探测方法是可行的.%The Greenland Ice Sheet is of extreme importance in relation to global climate, and the freeze-thaw characteristics of the ice sheet reflect Arctic climate change. Using Microwave Radiation Imager (MWRI) data acquired by the Chinese FY-3 satellite, the Cross-Polarized Gradient Ratio (XPGR) method is intro-duced, which increases the otherness of dry and wet snow. The Support Vector Machine (SVM) hyperplane, which has better detection capability compared with the existing threshold method, is used to detect freeze-thaw information on the Greenland Ice Sheet. Comparison of the results with Special Sensor Micro-wave Imager (SSM/I) data (with a threshold of-0.025) showed the proposed method (i.e., XPGR combined with SVM) is feasible for the detection of surface freeze-thaw information on the Greenland Ice Sheet.