Research On Airborne LiDAR Strips Matching Based On ICP Algorithm

Airborne laser radar is a developing high-tech active remote sensing technology,it can acquire large-area terrain data to rapidly generate DEM products^[40].Combining image data it can acquire abundant spatial geography information.Airborne LiDAR technology has been widely used in forestry,transportation,urban three-dimensional modeling and other aspects,whether the accuracy of the acquired data can meet the application requirements is a key issue for people.Due to the complexity of the airborne LiDAR system,it produce systematic error when performing measurement tasks and it have system error of the equipment itself.In addition,the scanning angle and flight height of the airborne LiDAR system are limited.Therefore,the width of the scanning strip is limited,when carrying out a large-scale survey,it is necessary to fly multiple strips to cover the survey area.Due to the existence of systematic error,there will be a three-dimensional spatial offset between target points with the same name in adjacent navigation strips.In order to reduce or eliminate the three-dimensional space offset caused by systematic error,and improving the accuracy and processing speed of LiDAR data,this paper proposes to use the improved ICP algorithm to match airborne LiDAR strips.Firstly,this paper summarizes the domestic and international research status of airborne LiDAR strips matching methods at home and abroad,points out its shortcomings,and gives the method and technical route for airborne LiDAR strips matching in this paper.On this basis,the measurement system and ground positioning principle of airborne laser radar are studied,establishing different imaging models for different scanning methods of airborne LiDAR systems,according to the principle of airborne LiDAR ground positioning,a coordinate transformation model was established.Combining the airborne LiDAR imaging model with the coordinate turning model to complete the conversion of the airborne LiDAR from the original one-dimensional ranging data to the three-dimensional coordinates under the WGS-84coordinate system,providing the basis for subsequent data processing.Then this paper analyzes the data error sources of airborne LiDAR and proposing a strips matching method based on ICP algorithm,and compared with other route adjustment methods to indicate their advantages and disadvantages,optimizing and improving the ICP algorithm implementation process.Finally,using PCL technology to complete the experiment of strips matching based on improved ICP algorithm.And evaluating the strips matching effect and accuracy,it is proved that the improved ICP algorithm can achieve airborne LiDAR strips matching,and the strips matching effect is good and weakens the three-dimensional space offset existing between adjacent strips caused by systematic error.