针对激光主动成像图像信噪比较低、目标难以被实时探测和识别的问题,提出了一种多通道序贯概率比检验(SPRT)的激光主动成像目标探测方法。基于原始观测数据,构造对数似然比检验,给出似然比判据及阈值的计算方法。结合激光主动成像的多通道特性,采用序贯概率比检验,在给定虚警概率和检测概率的情况下,对仿真的强度像和距离像通道进行探测。理论分析和实验结果表明,该方法能够实现对激光主动成像图像中目标的可靠检测,且具有检验速度快、所需样本少以及可在线计算等优点,可以满足激光主动成像制导中目标探测的准确性和实时性要求。
To solve the target detection problem caused by the low signal-to-noise ratio (SNR) of the laser active imaging system, a multichannel sequential detection algorithm is presented. Based on the original observed data, the calculation for judging threshold of laser active imaging system is proposed according to the generalized log-likelihood ratio. The multichannel characteristics of laser active imaging system are considered and the sequential probability ratio test (SPRT) is implemented to detect the targets in intensity image channel and range image channel, while controlling the rates of false alarms and missed detections. Theoretical analysis and experimental results show that the performance of the multichannel sequential detection algorithm is excellent. The results allow us to conclude that the use of the sequential detection algorithm substantially reduces the required time and the sample size of the system. This new target detection method satisfies the accuracy and real time requirements for laser active imaging guidance.