Assessing the applicability of terrestrial laser scanning for spatial snow depth measurements

Abstract

Abstract Snow depth observation in potentially dangerous avalanche-starting zones is important for avalanche prediction and dimensioning of permanent protection measures. The possible danger of avalanches complicates measurements of snow depth in the field (e.g. by probing). Therefore, the applicability of terrestrial laser scanning to measure the depth of the snow cover was analysed. Different long-range laser profile measuring systems were used carrying out numerous field campaigns (Vorarlberg, Austrian Alps). The objective of the study was to discover under which meteorological and snowpack conditions the measurements must be taken in order to provide accurate results ( 1 mm) only 50% of the emitted signal was received, depending on the angle of incidence. In any case, the accuracy decreases with increasing distance to the target. For distances to the object of more than about 500 m, the accuracy that can be achieved with the used TLS measuring systems is rather low and the errors can be significantly larger than 10 cm.