星载激光测高仪系统接收滤波器的带宽优化设计  

Optimizational Design Method for Receiver Filter Bandwidth of Satellite Laser Altimeter

作　　者：周辉[1] 李松[1] 郑国兴[1] 涂兰芬[2] 张强[2] 

机构地区：[1]武汉大学电子信息学院,湖北武汉430072 [2]中国空间技术研究院,北京100094

出　　处：《中国激光》2012年第9期136-140,共5页Chinese Journal of Lasers

基　　金：国家自然科学基金(40901165);民用航天"十二五"预先研究项目;中央高校基本科研业务费专项资金(274805)资助课题

摘　　要：星载激光测高仪(SLA)接收滤波器带宽(RFB)直接决定系统的使用性能。根据星载激光测高仪的工作原理,建立了激光测高仪回波信号及输出信噪比(SNR)的简化模型,并推导了测距误差、探测概率和虚警概率的数学表达式。在探测概率和虚警概率满足阈值要求的前提下,提出了一种以测距误差最小化为依据的滤波器带宽优化设计方法。以MOLA-2星载激光测高仪系统为例,仿真计算出不同目标倾角对应的滤波器带宽值及其测距误差的分布规律。结果表明,在0°～40°目标倾角范围,滤波器带宽优化设计值比传统方法设计的结果要大,其差异达到0.7～58.7MHz,而对应的测距误差要小于传统方法解算的数值,其差异为0.2～16.2m。受测量对象多样性和复杂性的限制,无法使每个探测目标对应一个滤波器,则采用多个通道的滤波器分段式地对优化的测距误差分布曲线进行拟合,以获取到每个通道的滤波器带宽及对应的探测目标倾角范围。滤波器带宽优化设计方法为其实际制造提供了一种更为优越和可行的方案。Receiver filter bandwidth（RFB） of satellite laser altimeter（SLA） resolves the key performances of SLA.According to the operational principle of SLA,the theoretical models of received signal and receiver signal-to-noise ratio（SNR） are established,and the mathematical expressions about range error,probability of detection and false alarm are deduced.Under the condition that probability of detection and false alarm can satisfy the threshold,an optimizational design method for RFB on the basis of minimizing the range error is put forward.As an example of MOLA-2,the distributions of RFB and range error related with different target slope angles are simulated.The results show that the optimizational design values of RFB are larger than values given by conventional method within 40° target slope angle,whose difference limits the scope from 0.7 MHz to 58.7 MHz.However,corresponding range errors are less than them obtained by conventional method,the extent of their difference is 0.2~16.2 m.With the restrictions of target variety and complexity,it is difficult to make every target correspond with a receiver filter during its manufacture,so multiple receiver filter channels are set up to piecewise fit the distribution curve of range errors,the RFB and corresponding scope of target slope angle for each channel are achieved.The optimizational method of designing the RFB provides a superior and practicable scheme for manufacturing receiver filter.

关 键 词：遥感 星载激光测高仪 滤波器带宽 信噪比 测距误差 多通道 

分 类 号：TN249[电子电信—物理电子学] P216[天文地球—测绘科学与技术]