Adjustment of Airborne Laser Altimetry Strips

Whereas the objectives of a strip adjustment procedure are simple to define, namely improving the accuracy of laser data and creating a seamless dataset, achieving them is difficult. Complex data acquisition systems and data that carry only little information are two aspects that make the formulation of a strip adjustment model difficult. Furthermore, difficulties in processing the data manually and the existence of partial data that usually contain only the laser points but not the system measurements, are other aspects that should be handled by a strip adjustment algorithm to make it useful. This paper presents a 3D system-driven strip adjustment algorithm. Based on the properties of the data the error recovery model is surface based. To eliminate manual processing of the data, handling tie and control information is autonomous, and to have the model applicable, the input data are the laser points. The application of the procedure is demonstrated here for the estimation of GPS biases to analyze the magnitude of positional offsets in the data. Results show the existence of significant errors in position.