闪电河流域L波段地基微波辐射计RFI检测与电磁环境分析  

Detection of RFI in Ground-based L-band Radiometer and Analysis on Electromagnetic Environment in the Shandian River Basin

作　　者：姜涛[1] 郑兴明[1,2] 李晓洁[1] 李晓峰[1] 赵凯[1,2] Jiang Tao;Zheng Xingming;Li Xiaojie;Li Xiaofeng;Zhao Kai(Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences,Changchun 130102,China;Changchun Jingyuetan Remote Sensing Test Site,Changchun 130102,China)

机构地区：[1]中国科学院东北地理与农业生态研究所遥感与地理信息研究中心,吉林长春130102 [2]中国科学院长春净月潭遥感实验站,吉林长春130102

出　　处：《遥感技术与应用》2021年第5期1022-1032,共11页Remote Sensing Technology and Application

基　　金：国家自然科学面上基金项目“基于多频段电磁波传播特性的森林枯枝落叶层参量反演方法研究”(41771400);“土壤水分与表面粗糙度的光学与雷达遥感协同反演算法研究”(41971323);遥感科学国家重点实验室开放基金项目“地基亮温观测与机载亮温不确定性评估”(OFSLRSS201815);“东北积雪多角度微波辐射特性观测、模拟与参数反演”(OFSLRSS202018);中国科学院科技服务网络计划“天-空-地一体化的农业灾害信息监测研究”(KFJ-STS-ZDTP-048-04-03)。

摘　　要：L波段微波辐射计是探测土壤湿度和海水盐度的重要手段,但日益严重的射频干扰(Radio Frequency Interference,RFI)使得L波段被动微波遥感无法达到地表参数的反演精度要求。将具有快速采样能力的L波段积分式微波辐射计搭载于车载移动平台,在华北闪电河流域进行地基测量,应用时域脉冲检测算法(Asynchronous Pulse Blanking algorithm,APB)及基于变异系数的中值比较算法对测量结果进行射频干扰检测与抑制,两种算法对射频干扰检测都取得了一定的效果。根据检测结果,闪电河综合遥感试验区的L波段地基微波辐射计观测到的射频干扰以小量级的脉冲式干扰为主,野外干扰平均量级一般集中在3~4 K,持续时间多在1~2 ms,干扰率在2%~14%之间。对比分析发现,城镇中的射频干扰较野外严重,野外实验中H极化测量结果受射频干扰影响略轻于V极化,APB算法相对具有较多的误检现象,而中值比较法则更能容许测量目标本身的辐射亮温波动,该算法的最小检测干扰量级小于3 K,有助于提高试验区内土壤湿度的反演精度。The L-band microwave radiometer is an important experimental equipment for detecting soil mois⁃ture and Sea Surface Salinity(SSS).However,the increasingly Radio-Frequency Interference(RFI)makes the L-band passive microwave remote sensing unable to meet the inversion accuracy requirements of ground surface parameters.In this paper,an integral type L-band microwave radiometer with fast sampling capacity is mounted on the vehicle mobile platform.The ground measurement is carried out in the Shandian River Basin of North China.The Asynchronous Pulse Blanking algorithm(APB)and the median comparison algorithm based on the coefficient of variation are used to detect and mitigate the radio-frequency interference of the measured results.Both of two algorithms have achieved a certain effect on radio-frequency interference detection.According to the test results,the RFI observed by the L-band ground-based microwave radiometer in the remote sensing ex⁃perimental area of the Shandian River is mainly small-scale pulsed interference,the field interference level is generally 3~4 K,most interference persist 1~2 ms,and the interference rate is between 2%and 14%.The analysis shows that the field interference magnitude in the experimental area is significantly smaller than that in the cities and towns,and the interference to V polarization is slightly more serious than that to H polarization.It is found that the APB algorithm has more false detection phenomena or False Alarm Rate(FAR),while the me⁃dian comparison algorithm based on the coefficient of variation can more tolerate the radiation brightness temper⁃ature fluctuation of the target itself,and the minimum detection interference level or magnitude of the latter algo⁃rithm is less than 3 K.The measurement data of ground-based L-band passive microwave radiometer will con⁃tribute to the verification and calibration of remote sensing data of both aviation and satellite.

关 键 词：L波段微波辐射计 土壤水分 射频干扰 时域检测算法 中值比较算法 变异系数 电磁环境分析 

分 类 号：TP701[自动化与计算机技术—检测技术与自动化装置]