球形标靶的固定式扫描大点云自动定向方法

根据目前地面激光扫描数据获取速度快、数据量大、测量距离远、专用特殊材料制作的标靶识别距离近、点云定向数据处理相对滞后、自动化程度低、不能适应远距离地形测量的现状,提出了从大点云中(每站1亿点以上)自动探测远距离标靶的点云定向方法。该方法首先根据标靶控制点的工程测量坐标信息,搜索到标靶所在点云环,然后对各点云环进行扇形分区,快速探测标靶,获取标靶中心扫描坐标,最后平差计算扫描仪位置参数和姿态参数,实现点云坐标到工程测量坐标的转换。该方法在普通配置的计算机上得到实现,并成功用于远距离山区地形测量,其中定向标靶半径0.162m,标靶到扫描站距离在180~700m之间。

An Approach for Automatic Orientation of Big Point Clouds from the Stationary Scanners Based on the Spherical Targets

Terrestrial laser scanning (TLS)technology has high speed of data acquisition,large amount of point cloud,long distance of measuring.However,there are some disadvantages such as distance limita‐tion in target detecting,hysteresis in point clouds processing,low automation and weaknesses of adapting long‐distance topographic survey.In this case,we put forward a method on long‐range targets detecting in big point clouds orientation.The method firstly searches point cloud rings that contain targets according to their engineering coordinate system.Then the detected rings are divided into sectors to detect targets in a very short time so as to obtain central coordinates of these targets.Finally,the position and orientation parameters of scanner are calculated and point clouds in scanner's own coordinate system(SOCS)are converted into engineering coordinate system.The method is able to be applied in ordinary computers for long distance topographic(the distance between scanner and targets ranges from 180 to 700 m)survey in mountainous areas with targets radius of 0.162 m.