地基GNSS-R在复杂地形条件下的积雪探测  

Snow detection under the complicated terrain conditions using the ground-based GNSS-R technique

作　　者：管栋良 梁子亮[3] 王勇 GUAN DongLiang;LIANG ZiLiang;WANG Yong(School of Geomatics Science and Technology,Nanjing Tech University,Nanjing 211816,China;Aerospace Information Research Institute,Chinese Academy of Sciences,Beijing 100094,China;Provincial Geomatics Centre of Jiangsu,Nanjing 210013,China;State Key Laboratory of Geodesy and Earth′s Dynamics,Innovation Academy for Precision Measurement Science and Technology,Chinese Academy of Sciences,Wuhan 430071,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]南京工业大学测绘科学与技术学院,南京211816 [2]中国科学院空天信息创新研究院,北京100094 [3]江苏省基础地理信息中心,南京210013 [4]大地测量与地球动力学国家重点实验室,中国科学院精密测量科学与技术创新研究院,武汉430071 [5]中国科学院大学,北京100049

出　　处：《地球物理学报》2022年第11期4236-4248,共13页Chinese Journal of Geophysics

基　　金：国家重点研发计划(2021YFB3901301);江苏省自然科学基金青年基金(BK20220366);大地测量与地球动力学国家重点实验室开放基金(SKLGED2019-5-2-E)资助.

摘　　要：GNSS-R技术是一种以GNSS为信号源的全新遥感技术,可用于监测海洋和陆地.在地基GNSS-R积雪探测研究中,反射区域内的复杂地形不仅会引起积雪的不均匀分布,还使得接收机能在同一时刻接收到来自多个反射界面的反射信号,从而增加了积雪探测的难度.针对该问题,本文利用北极圈内斯匹次卑尔根岛上布设的GNSS-R测站,开展了复杂地形条件下的积雪探测研究.根据不同界面上的反射信号具有不同多普勒频移的特点,本文提出了基于傅里叶变换的谱分析方法,将不同界面的反射信号从混合信号中分离出来,并根据特定多普勒频率段的功率来监测地表积雪变化.基于该方法,本文分析了反射路径位于Schetelig山地区域的8颗卫星在2014年间的反射信号,计算结果表明:卫星PRN 2、12和28与积雪地面介电常数之间的相关系数分别为0.02、0.20和0.05,表明这三颗卫星的反射信号与地面介电常数之间不相关;卫星PRN 14和20与地面介电常数之间的相关系数分别为0.29和0.26,为低度相关;PRN 17、18和25与地面介电常数之间的相关系数分别为0.43、0.54和0.44,为中等程度相关.研究证明本文提出的方法,可用于探测复杂地形下的地表积雪.GNSS-R is a novel remote sensing technique,which use the GNSS signal as the sources.It can be used to monitor the ocean and the land.In the research of ground-based GNSS-R snow detection,the complicated terrain of the reflected zone will not only cause the irregular distribution of the snow cover,but also make the GNSS-R receiver to receive the reflected signal from different reflected facets at the same time,which increases the difficulty of detecting the snow.To address this issue,this paper focuses on the snow detection under the complicated terrain conditions using the GNSS-R station set up in the Spitsbergen Island close to the Arctic Pole.According to the different Doppler frequencies of the different facets,a Fast Fourier Transform(FFT)based method has been proposed to separate the reflected signal from the different facets.Then,the power of the separated reflected signals has been used to detect the snow.This paper uses the above method to analyze the reflected signal from eight different satellites whose reflected tracks pass through the Schetelig mountain during 2014.The results shows that the coefficients between the reflected signal of satellites PRN 2,12 and 28 and the ground dielectric constant are 0.02,0.20,and 0.05,which shows that these three satellites have no relation with the ground dielectric constant;the coefficients between the reflected signal of satellites PRN 14 and 20 and the dielectric constant are 0.29 and 0.26,which means that these two satellites have weak relationship with the ground dielectric constant;the coefficients between the reflected signal of satellites PRN 17,18 and 25 and the ground dielectric constant are 0.43,0.54 and 0.44,which means that these three satellites have moderate relationship with the status of the dielectric constant.This research proves that the method proposed here can be used to detect the snow under the complicated terrain conditions.

关 键 词：地基GNSS-R 积雪探测 傅里叶变换 多普勒频移 

分 类 号：P228[天文地球—大地测量学与测量工程]