Until today, snow depth data is mostly estimated based on point measurements, either collected manually or at automated weather stations. New photogrammetric technologies to map the snow depth distribution spatially continuous over larger areas are rapidly evolving. Especially in the field of unmanned aerial systems (UAS) new systems with better cameras and longer flight times are being developed. However, the specific strengths and weaknesses as well as the performance considering accuracy on homogeneous snow surfaces are not yet sufficiently investigated.

Therefore, we have simultaneously tested different photogrammetric platforms and sensors for snow depth mapping in the high alpine Dischma valley close to Davos (Switzerland) during winter season 2017/18. An extraordinarily snow rich winter challenged the data referencing approaches in particular. We acquired data over the whole Dischma valley with satellite and airplane based optical sensors. At two subsets in the Dischma valley, we flew with two different UAS and acquired ground-based data with a digital consumer camera. For the independent validation of the photogrammetric products we applied terrestrial laser scanning and measured snow depth by probing as well as by measurements on fixedly installed snow poles.

In this study we outline the experimental setup for a large campaign with different photogrammetric sensors and platforms. That will allow for an improved understanding of the specific advantages and disadvantages of different photogrammetric systems for operational, spatially continuous snow depth mapping in high alpine terrain over large areas.