Build guide for a non-contact snow depth sensor using ultrasonic and temperature compensation.
How the Sensor Works
The snow gauge in the 3D-PAWS system measures snow depth using a combination of ultrasonic and temperature sensing technologies. Mounted above the ground, the MaxBotix HRXL-MaxSonar-WRLS ultrasonic sensor emits high-frequency sound pulses toward the snow surface. These pulses reflect off the snow, and the sensor measures the time it takes for the echo to return. By calculating this time and accounting for the speed of sound in air, the system determines the distance from the sensor to the snow surface. As snow accumulates, this distance decreases, allowing for continuous tracking of snow depth.
To ensure accurate measurements in all weather conditions, the system uses an external MB79XX HR-MaxTemp temperature sensor. This sensor monitors the air temperature near the ultrasonic sensor, allowing the system to automatically adjust for changes in the speed of sound caused by temperature fluctuations. This dual-sensor approach provides reliable, real-time snow depth data, even during periods of rapid temperature change.
