Research Of Error Calibration Methods Of Airborne Lidar System

The airborne LiDAR (Light Detection And Ranging) is an earth observation technology of representing an available collection of laser scanning technology, global positioning technology, and inertial navigation technology. The airborne LiDAR has many characteristics, such as less impacted from weather, high automation degree and shorter mapping cycle. At present many domestic research institutes and companies have introduced high-performance airborne LiDAR systems with small footprint from foreign counties. However, this import model has its disadvantages of high price and secret software algorithms. Thus it urgently needs to develop high accuracy airborne LiDAR system with our own intellectual property rights. However, no metter international or domestic LiDAR technology needs to eliminate systematic errors instantly, which is the key point this paper discusses.The performance of airborne LiDAR is affected from several factors, such as laser scanner's range and angle measurement errors, POS' position and orientation measurement errors and system integration errors and so on. The working principle of each part of airborne LiDAR system, the coordinate systems related to LiDAR system and its surveying principle are analyzed in this paper. Based on the domestic light-small airborne LiDAR system, this paper particularly studies the error sources of the airborne LiDAR system, states the error correction methods of laser scanner's range and angle measurements, IMU's measurements, and the systematic mounting-angle calibration method based on ground test field of flight simulation with relevant error correction models. The specific contents of this paper are as follows:1. The airborne LiDAR system surveying principle, several international typical commercial airborne LiDAR systems and comparation with photogremmetry and airborne InSAR will be presented in this paper;2. The analysis of airborne LiDAR system error sources, present situation and dominant methods of error calibration research;3. The discussion of laser scanner calibration, which includes range and angle detecting error calibration, with range accuracy of 3cm and angle of 1% degree after calibration;4. Accuracy determination method of IMU will be mentioned in this paper. It consists of three accuracies:initial alignment accuracy, static drift accuracy and dynamic trial accuracy; 5. Based on ground test field of flight simulation and relevant error correction models, the systematic parameters of mounting angles are calculated.3D coordinates RMS of laser points are in 2cm with 50m flight height.