一种应用图像配准叠加提高成像激光雷达测距精度的方法

Image Registration and Superposition for Improving Ranging Accuracy of Imaging Laser Radar

介绍了一种基于增益调制测距原理的成像激光雷达,并分析了其在散粒噪声受限时的测距精度。根据该精度模型,针对机载应用提出了对雷达测得的距离图像序列进行配准叠加以提高测距精度的方法。由于各帧图像的距离精度不同,在配准前进行权重处理使精度较高的图像像素获得较大的权重,然后利用插值相位相关法进行精确配准。对于配准后的图像,利用加权叠加使相加后的距离图像误差最小。理论分析表明,该方法能有效整合不同帧探测到的信号,使n帧距离图像配准叠加后的测距误差降低为单帧的1/n。仿真和实验验证了该方法的有效性。

A laser radar based on ranging principle of gain modulation is introduced,and its distance measurement accuracy under shot noise limited circumstances is analyzed.According to the accuracy model,a method which uses techniques of image registration and superposition is presented to improve ranging accuracy in airborne applications.For differences of distance accuracy among range image sequences,a weighted processing before registration is used for the purpose of assigning high weights to pixels with high accuracy,and a registration method called up-sampled phase correlation is used to locate image sequences accurately.The range images after registration are weighted superposed to minimize range error.Theoretical analysis shows that this method can effectively integrate detected signals among different frames.If n frames range images are superposed,the range error will be 1/n of one frame.Simulation and experimental results are demonstrated to verify the effectiveness of this method.