基于FPGA的星载激光测高仪飞行时间测量  

Measurement of flight time for satellite laser altimeter based on FPGA

作　　者：姚萍萍[1] 赵欣[1] 张毅[1] 涂碧海[1] 赵平建[1] 

机构地区：[1]中国科学院安徽光学精密机械研究所,安徽合肥230031

出　　处：《红外与激光工程》2008年第4期679-682,共4页Infrared and Laser Engineering

摘　　要：激光测高仪是通过测量激光脉冲的飞行时间来获得测高仪与测量目标之间的距离,因此激光飞行时间测量的准确性是衡量其系统能力的根本指标。研制了在星载激光测高系统中基于单芯片现场可编程门阵列(FPGA)的激光飞行时间测量模块。该模块采用高频计数法结合数字内插法的技术,且单片FPGA的使用提高了激光测高仪的距离分辨率、缩短了测量时间,同时大大简化了电路结构和系统体积,受外界环境干扰小,十分符合星载激光测高要求。最后通过地面检测,整个系统在500km范围内一般条件下获得±50cm的测高精度。Pulsed time-of-flight laser altimeter transmitts a short laser pulse to an optical visible target and measures the flight time of the reflected pulse with an optical detector. The measured distance is calculated by the flight time. So the accuracy of the flight time interval is a basic specification of the system . The flight time measurement module based on a single field-programmable-gate-array （FPGA） in satellite laser altimeter was developed. This module combined the high frequency digital counting and digital interpolation techniques. Benefiting from the utilization of a single FPGA,the range resolution and the measuring speed were improved. This system was adapted extraordinarily to satellite laser altimeter for its compactness,simple structure and high reliability. Furthermore,detection on the ground shows the measuring precision is±50 cm over 500 km ranges under general conditions.

关 键 词：激光测高仪 时间间隔测量 FPGA 距离分辨率 

分 类 号：TN248[电子电信—物理电子学]