ABSTRACT
This chapter discusses the applied ranging principles and the achievable ranging accuracy is estimated by link budget calculations. It presents the Light Detection and Ranging (LiDAR) link budget calculation that was reduced to the simpler forms in order to highlight the key parameters that govern instrument performance. For understanding the functioning of the different LiDARs, for evaluating the performance of the instrument components and for selecting the right components appropriate for specific surveying tasks, the principles of LiDAR systems are described by subdividing the whole system into functional subunits. Most LiDARs are realized with conventional optics. Data handling for fullwave recording LiDARs is even more demanding, because the full receive pulse shape is digitized rather than simply ranging to its leading edge. The combination of LiDAR and Position and orientation system (POS) units may vary from survey to survey, and for research purposes often several POS are flown together for comparative studies.
