【作者】 王立成；

【导师】 马东洋；

【作者基本信息】 解放军信息工程大学 ， 摄影测量与遥感， 2011， 硕士

【摘要】 LiDAR( Light Detection and Ranging)技术是一种全新的获取地理信息数据的手段,具有普通的摄影测量无法比拟的优势。由于存在着LiDAR系统数据精度还无法满足成图要求、进口的大量LiDAR无法知道其是否达到出厂标称值、国内正在研发的LiDAR质量指标怎样确定是否过关等等需求,急需开展针对LiDAR的检校与标定的研究工作。本文以国内正在研发的LiDAR仪器为例,设计了针对该仪器的激光测距误差的确定以及纠正方法,并对该仪器锥扫角和扫描角的误差纠正方法进行了深入的分析,根据分析结果给出了其误差改正方法。本文主要的工作和创新点如下:1.根据LiDAR系统的组成及其工作方式原理,详细推导了LiDAR系统的定位公式方程,把LiDAR系统误差与公式中的各参数进行结合分析讨论,给出了各项主要误差产生的原因及其对点云数据的影响方式。2.对LiDAR测距误差进行了详细的分析,设计了一种简单可行的对激光测距误差的测定方法,并对误差结果进行总结分析讨论。提出了一种把测距误差分两步纠正的方法,第一步是针对回波强度不同引起的误差进行改正,方法是根据误差值与回波强度关系曲线图给出拟合公式,对误差进行拟合;第二步是针对固定的系统误差进行改正,基于对误差的理论经验与数据分析,给出拟合公式进行拟合。由误差改正前后效果对比可以看出该方法切实可行,效果明显。3.分析了LiDAR仪器锥扫角产生的原因、对点云结果的影响方式,讨论了锥扫角与集成误差中俯仰角误差对点云结果影响方式的不同。提出了一种估计锥扫角误差大小的试验方法,该方法虽然不够完善,但是由实验结果可以看出对于估计锥扫角的大致范围还是有一定的效果,方法有待于进一步完善。4.分析了扫描角误差产生的原因,给出了测定扫描角误差的方法。根据扫描角误差曲线的规律给出了拟合曲线方程,求出拟合参数。实验结果表明该方法切实可行,对扫描角误差纠正效果比较明显。更多还原

【Abstract】 LiDAR (Light Detection and Ranging) technology is a freshly new mean to access GIS data, with great advantages which can not be matched by common photogrammetry. Since the accuracy of LiDAR system data can not meet the requirements of mapping, and the nominal value of a large number of LiDAR systems imported can not be known, domestic indicators are being developed for LiDAR in our country, and therefore, the calibration of LiDAR systems is needed to be researched greatly. In this paper, based on LiDAR instruments developed in our country, laser ranging error determination and calibration methods are designed, instrument cone scan angle and scan angle error correction methods are analyzed in-depth, and based on the analysis, error correction methods are given. In this paper, the work and innovations are as follows:1. According to the composition and working principles of LiDAR system, positioning formulas for LiDAR system are derived in detail. Comparing with the formula parameters, LiDAR system errors are discussed. And then, the major causes of each error and its impacts on point cloud data are given,2. LiDAR ranging error is analyzed in detail, a simple and feasible method for the determination of the laser ranging error is designed, and the error results are summarized and discussed. Then, a two-step ranging error calibration method is proposed. The first step is calibration of errors cased by different echo intensity. Based on error value and the relationships between echo intensity, curve fitting formulas are derived to fit the error. The second step is the calibration of fixed system errors. Based on theoretical experience and data analysis of errors, curve fitting formulas are given. Comparing the effect before and after error calibration, it can be seen that the method is quite feasible and effective.3. In order to analyze the causes of LiDAR instrument cone scan angle and its impact on point clouds, differences between the impact of cone scan angle error and pitch angle error to point clouds are discussed. Moreover, a testing method to estimate the size of the cone scan error scan is proposed. Though it is not perfect, the method has a certain effect to estimate the general scope of cone scan angle from experimental results. And of course, the method has to be improved further.4. The causes of scan angle error are analyzed, and methods to measure scan angle error are given. According to the law of scan angle error, curves are fitted and parameters are obtained, Experimental results show that the method is feasible and has obvious effects on error calibration.更多还原