应用分块复原方法提高激光雷达测距精度

介绍了一种基于像增强器增益调制原理的三维成像激光雷达,距离图可以由恒定增益和线性增益调制条件下的灰度图计算得到。根据成像系统的传递特性,建立了灰度图像的退化模型并分析了在考虑点扩散函数影响的情况下,引起成像激光雷达测距误差的主要原因。分析结果表明,在距离变化区域,测距误差主要与点扩散函数、反射率和实际距离等因素有关;而在平坦区域,测距误差主要由散粒噪声引起的。根据误差的来源和散粒噪声的特点,提出了对拍摄得到的灰度图像进行分块复原的方法。仿真结果显示:该方法复原得到距离图的均方根误差比全局复原方法小。最后将该方法用于实际拍摄的雷达图像,验证了该方法的有效性。

Improvement of ranging accuracy of imaging laser radar with sectioned restoration method

A three-dimensional imaging laser radar using intensified CCD as the receiver with constant gain and line modulated gain was introduced,the distance map of a scene was obtained from two intensity images.According to the transmission characteristics of the imaging system,a model of degeneration of the gray images was established and the ranging accuracy of imaging laser radar based on this model was analyzed.The results show that the ranging accuracy is related with the point spread function,the reflectivity and the actual distance for the uneven region,while it is mainly concerned with shot noise for the flat region.On the basis of the cause of measurement error and the characteristics of noise,a method applying sectioned restoration on obtained gray images was presented.The simulation results show that root mean square error of distance map obtained with this method is smaller than the global restoration method.Finally the method was applied in the restoration results of radar images and its effectiveness was verified.