RADIOMETRIC CALIBRATION OF TLS INTENSITY: APPLICATION TO SNOW COVER CHANGE DETECTION

Abstract. This paper reports on the radiometric calibration and the use of calibrated intensity data in applications related to snow cover monitoring with a terrestrial laser scanner (TLS). An application of the calibration method to seasonal snow cover change detection is investigated. The snow intensity from TLS data was studied in Sodankylä, Finland during the years 2008–2009 and in Kirkkonummi, Finland in the winter 2010–2011. The results were used to study the behaviour of TLS intensity data on different types of snow and measurement geometry. The results show that the snow type seems to have little or no effect on the incidence angle behaviour of the TLS intensity and that the laser backscatter from the snow surface is not directly related to any of the snow cover properties, but snow structure has a clear effect on TLS intensity.