The Canadian automatic snow depth sensor: a performance update

In Canada, a need exists for a reliable, low cost automatic snow depth sensor. The Atmospheric Environment Service (AES) has developed and tested an acoustic ranging device, which provides an accurate and economical method of measureing snow depth remotely. The AES sensor has been licensed for commercial manufacture. Field tests were conducted at various sites across Canada, to assess the accuracy and performance of the sensor. Results indicated that the automatic sensor measured within plus-or-minus 2.5 cm of independent ruler measurements, and over the winter season, its measurement time series replicated daily ruler measurements. The sensor is now configured to measure with a 1.00 mm resolution; however, it is not practical to expect measurement accuracies of this precision over such a dynamic surface as snow. Factors which can influence the measurements of snow depth and snowfall using acoustic ranging devies are presented. With proper siting, the AES Automatic Snow Depth Sensor provides a reasonable and accurate measurement of snow depth.