Simultaneously with the ADS80 data acquisition, a field
team acquired manual snow depth measurements using a
3.2m avalanche probe at 15 different plot locations within
the test site Wannengrat. A plot consists of 55 probe measurements
with a distance of 2m between points (Fig. 2a),
resulting in 375 single-probe measurements localized using
dGNSS data of the corner points. Because snow depth can
vary substantially within the distance of some decimeters
if there is, e.g., a rock at the surface (Lopez-Moreno and
Nogues-Bravo, 2006), we use the average snow depth and the
standard deviation to compare it to the corresponding ADS80
snow depth values within this 1010m area (Fig. 2b). The
acquisition of field measurements is very challenging because
the terrain is steep and human mobility is limited. The
avalanche danger for wet snow avalanches rises quickly during
the day due to sunny spring weather conditions, limiting
the time the field team can move within the test sites. Therefore,
the number of performed field measurements at 15 plots
distributed over an area of 11.5 km is close to the possible
maximum that can be obtained with the number of those participating
in the experiment. Because this number is, in our
opinion, not sufficient to assess the potential of the method
proposed, we apply further reference data sets.