The development of an inexpensive ultrasonic ranging device to provide reliable snow depthmeasurements at automatic stations has provided a feasible alternative to the standardobservation,both for snow depth and fresh snowfall (Goodison et al.,1988).Several ultrasonicmodels exist on the market and are commonly used with automatic systems.This type of sensorcan also be utilized to control the quality of automatic recording gauge measurements byproviding additional details on the type,amount and timing of precipitation.It is capable of anuncertainty of 士1cm.The temperature correction formula for ultrasonic snow depth measurement is: