【作者】 陈锺贤； 范韵； 赵远； 孙秀冬；

【Author】 CHEN Zhong-xian,FAN Yun,ZHAO Yuan,SUN Xiu-dong(Department of Physics,Harbin Institute of Technology,Harbin 150001,China)

【机构】 哈尔滨工业大学物理系；

【摘要】 无扫描激光大光场照明时目标处的光强甚弱,通常需要加大激光器的功率和提高探测器的灵敏度。从探测技术角度探讨提高系统探测灵敏度的技术途径,即将光子计数技术应用于激光脉冲探测系统。光子计数探测的动态范围为10?1 6～10?11 W,回波以离散光子流的形式照射在探测器的光敏面上。当接收系统检测模超过20时,光电子统计近似服从泊松分布规律。对于典型的激光脉冲探测系统,采用最大似然方法估算出探测阈值,并估算出平均探测时间。例如,对10?1 1 W回波,估算的积累时间为0.2 ms。针对脉冲探测情况,采用时间门选通多点采样的数据采集方法和多脉冲预积累相关处理算法。采样周期与激光脉冲宽度相等,时间门宽稍小于激光重复周期。根据探测误差概率的需要,采用Monte Carlo算法估算出探测积累的脉冲数和相关计算的参数。初步估算探测时间至少在10 ms量级。更多还原

【Abstract】 The signal scatted by a target is very weak in the scanner-less laser detecting system,as it need wide range illumination.The more powerful laser and more sensitive detector are required.Pulsed laser range finding using photon-counting technique is presented to improve the sensitivity of a detecting system.The dynamic range of photon-counting detection is 10 ?1 6 ～ 10 ?11 W.The returned signal is received as a discrete photon stream.The statistics of photons meets Poisson distribution when the detecting module exceed 20.For a typical pulse laser range finding system,threshold and average time of detection is calculated using maximum likelihood estimation.The estimated accumulation time is 0.2 ms for received signal power of 10 ?1 1 W.Time-gated multi-point sampling and multi-pulse accumulating and correlated processing is applied to the system.The sampling period is same as the laser pulse width.And the time gate width is less than the laser repeat period.A Monte Carlo simulation method is employed to calculate the pulse counts and the correlative parameters.The estimated detecting time is at 10 ms level.更多还原