摘要
星载全球导航卫星系统反射信号(GNSS-R)属于被动遥感技术,具有数据重访周期高、全天时、全天候、信号源丰富等优势。基于此,研究星载GNSS-R检测太湖水华的可行性。星载GNSS-R可以有效检测反射面的粗糙程度,通过使用相干反射表征反射面的粗糙度,研究不同风速区间内相干反射与蓝藻水华的关系。利用2020年4—8月美国气旋全球导航卫星系统(CYGNSS)数据,计算CYGNSS镜面反射点的时延多普勒图(DDM)功率比。以“哨兵-3”卫星水色遥感仪器(OLCI)影像最大特征峰高度(MPH)算法反演出的太湖叶绿素浓度作为参照,与欧洲中期天气预报中心(ECMWF)的风速产品进行时空间线性匹配,分析发现,在1~2.5 m/s风速区间内,叶绿素浓度达到0.1 mg/L以上时,极易引起镜面反射点发生相干反射,且功率比与叶绿素浓度的相关系数为0.84,具有良好的相关性。实验结果证明了利用星载GNSS-R的功率比及相关特性实现太湖水华检测的可行性。
Spaceborne global navigation satellite system-reflectometry(GNSS-R)is a passive remote sensing technology with the advantages of high data revisit cycle,all-day coverage,all-weather services,and abundant signal sources.Based on this,the feasibility of detecting water blooms in the Taihu Lake by on-board GNSS-R is studied.Spaceborne GNSS-R can effectively detect the roughness of the reflective surface.By using coherent reflection to characterize the roughness of the reflective surface,the relationship between coherent reflection and cyanobacterial blooms in different wind speed ranges is studied.The US cyclone global navigation satellite system(CYGNSS)is used to track the reflected signals of the global positioning system and calculate the power ratio of the delay Doppler map(DDM)of the CYGNSS mirror reflection point using CYGNSS data from April to August 2020.The chlorophyll concentration in Taihu Lake is used as a reference,retrieved from the maximum characteristic peak height(MPH)algorithm of the imagery from the ocean and land colour instrument(OLCI)aboard on“Sentinel-3”satellite.The time-space linear matching is also conducted with wind speed products of the European Centre for Medium-Range Weather Forecasts(ECMWF).Data analysis shows that in the range of wind speed 1−2.5 m/s and with the chlorophyll concentration reaching more than 0.1 mg/L,coherent reflection tends to occur at the specular reflection point,and the correlation coefficient between the power ratio and the chlorophyll concentration is 0.84,which has a good correlation.Experimental results verify the feasibility of detecting the Taihu Lake water bloom using the power ratio and related features.
作者
张云
王雨
周绍辉
孟婉婷
韩彦岭
杨树瑚
ZHANG Yun;WANG Yu;ZHOU Shaohui;MENG Wanting;HAN Yanling;YANG Shuhu(College of Information Technology,Shanghai Ocean University,Shanghai 201306,China;Shanghai Research Center of Marine Intelligent Information and Navigation Remote Sensing Engineering Technology,Shanghai 201306,China;Shanghai Aerospace Space Technology Co.,Ltd.,Shanghai 201109,China;Shanghai Academy of Spaceflight Technology,Shanghai 201109,China)
出处
《北京航空航天大学学报》
EI
CAS
CSCD
北大核心
2024年第3期695-705,共11页
Journal of Beijing University of Aeronautics and Astronautics
基金
国家自然科学基金(41871325,42176175)
国家重点研发计划(2019YFD0900805)。
关键词
气旋全球导航卫星系统
全球导航卫星系统反射信号
功率比
水色遥感仪器
最大特征峰高度算法
cyclone global navigation satellite system
global navigation satellite system-reflectometry
power ratio
ocean and land color instrument
maximum characteristic peak height algorithm
