Laser Pulse Variations and Their Influence on Radiometric Calibration of Full-waveform Laser Scanner Data

Full-waveform laser scanning extends the information content of “conventional” laser scanning by storing the temporal profile of both the emitted laser pulse and its echoes. This allows for calculating radiometric quantities in addition to the geometric data. This radiometric information needs to be calibrated in order to enable comparison among flight strips of the same laser scanner campaign and/or different campaigns. Radiometric calibration is aimed at the determination of a calibration constant which contains the parameters of the emitted laser pulse (besides others). All of these parameters are normally treated as constants. In this paper, the sensitivity of the calibration constant to variations of the emitted laser pulse is analysed theoretically by deriving it according to the error propagation law, followed by an empirical analysis carried out on the example of two airborne full-waveform laser scanning campaigns. Both were operated with the same instrument and over the same area on two different dates.