Accuracy Analysis Of DEM Based On Airborne LiDAR Data

Airborne Light Detecting and Ranging (Airborne LIDAR) is a new technique of surveying field and has received more and more concerning, the application field of this technique is more and more abroad too. As the technique can not only acquire elevation data quickly, but also gain a series of technique improvement in the field of remote sensing mapping and some other fields including topography surveying, environment monitoring, 3D city modeling, freeway and railway design and so on. Following the fast development of the airborne LIDAR hardware, the point cloud generated become more exact, but also more massive. As a result, how to process massive point cloud efficiently plays an important role in development of the technique. Furthermore, the analyzation of potential factors which may affect point cloud data precision have the important meaning.The acquire of point cloud data can be affected by many error sources which include GPS dynamic positioning error, INS attitude measuring error, laser data error etc. Besides, other factors also can affect the point cloud data precision, for instance, flight course designing, GPS base station setting, ground control point, coordinates transformation and so on.The paper analysis three kinds of factors which may influence point cloud data precision. It is flight course, GPS base station, ground control point. The main research is to analysis the absolute accuracy and the relative accuracy of point cloud data. The absolute accuracy analysis method is to compare the DEM accuracy under different combination of GPS base station and ground control point. The relative accuracy analysis method is to assess the flight course quality by compare the point cloud data accuracy of original parallel flight course and crossing flight course.