全极化微波辐射计中数字相关器的误差分析  

Quantification Error Analysis of Digital Correlator on Fully Polarization Microwave Radiometer

作　　者：黄邑燊 王振占 陆浩 Huang Yishen;Wang Zhenzhan;Lu Hao(Key Laboratory of Microwave Remote Sensing Technology,Chinese Academy of Sciences,Beijing 100190,China;National Space Science Center,Chinese Academy of Sciences,Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院国家空间科学中心微波遥感技术重点实验室,北京100190 [2]中国科学院国家空间科学中心,北京100190 [3]中国科学院大学,北京100049

出　　处：《遥感技术与应用》2019年第1期101-106,共6页Remote Sensing Technology and Application

基　　金：WCOM卫星背景预研项目

摘　　要：全极化微波辐射计是测量目标微波辐射特性的被动式遥感器,它是在传统的微波辐射计基础之上对幅度、频率和相位等极化信息的全部提取技术。数字相关器是利用高速模数转换器以及可编程逻辑器件FPGA实现对水平和垂直通路信号量化处理和相关运算。相比模拟相关器,数字相关器有高带宽和避免受到直流干扰的优点,但是在量化过程中也引入了量化误差。分析了空间中心研制的数字相关型全极化微波辐射计系统中8 bit量化对量化前后相关系数的影响。通过确定合适的A/D量化阈值,确保数字相关器的误差对辐射计系统的影响最小,并通过建模仿真验证了分析结论的可靠性。结果表明项目研制的8 bit数字相关器的量化误差对系统误差的引入量是可以忽略的。Fullypolarization microwave radiometer is a passive remote sensing device that measures the target’s microwave radiation characteristics.It is a complete extractiontechnology of polarization information such as amplitude,frequency and phase based on the traditional microwave radiometer.Digital correlator utilizes high-speed analog-to-digital converter and programmable logic device FPGA to realize quantification processing and related operations of horizontal and vertical channel signal.Compared to analog correlators,digital correlators have the advantage of high bandwidth and immunity from DC interference,but quantification errors are also introduced in the quantification process.This paperanalyzes the influence of 8 bit quantification on the correlation coefficient before and after quantification on digital correlation fully polarization radiometer whichdeveloped by NSSC.By determining the appropriate A/D quantification threshold,it is ensured that the error of the digital correlator has the least influence on the radiometer system.The reliability of the analysis conclusion is verified by modeling and simulation.The results show that the quantification error of 8 bit digital correlator developed by the project can be neglected to the system error.

关 键 词：全极化微波辐射计 数字相关器 8bit量化误差 

分 类 号：P407.1[天文地球—大气科学及气象学]