Ultrasonic Method for Monitoring Environmental Risks Associated with Precipitation

Abstract

This paper presents a solution that utilises ultrasonic technology to allow monitoring snow layer thickness or water level based on measurement from air. It describes the principle of operation of a measurement device using three methods of compensating for changing external factors affecting appliance's precision. Block diagram of the device is also provided. In order to verify the proposed solutions, the research team tested the device in laboratory and operating conditions. The results obtained this way make it possible to select a configuration of device operation depending on the required measurement precision and limitations associated with installing the system for actual operation.

A Study of a Parametric Method for the Snow Reflection Coefficient Estimation Using Air-Coupled Ultrasonic Waves

“…Analyzing Figure 8 and Figure 9 along with the correlation value between the snow level height and the reflection coefficient it can be said that snow level height variations affect the value of R . Taking into account the laboratory results presented in [ 17 ], where a linear dependency between snow density and pressure reflection coefficient was proved, this variation of R can be associated with the fresh water properties.…”

“…Analyzing the correlation matrix, it cannot be clearly stated that there exists any dependency of this parameter on the environmental variables presented on the Figure 12. Analyzing Figures 8 and 9 along with the correlation value between the snow level height and the reflection coefficient it can be said that snow level height variations affect the value of R. Taking into account the laboratory results presented in [17], where a linear dependency between snow density and pressure reflection coefficient was proved, this variation of R can be associated with the fresh water properties. The presented study of the method for the snow reflection coefficient estimation was performed using a single frequency of 50 kHz, due to application of the piezoelectric transducer ATK50, which works in a resonant mode.…”

“…As it can be found in the articles [ 16 , 17 , 18 ], the most accurate method for snow depth measurement using ultrasonic waves is the pulse-echo method, combined with parametric compensation of sound velocity changes along the temperature variations. The parametric method for distance estimation, uses a reflector positioned at a fixed distance that provides temporal reflector time of flight (TOF) , which then is used to estimate the unknown target distance as shown in Equation ( 1 ) where and corresponds to the TOF for a wave reflected from the snow surface, see the Figure 1 .…”

“…The experiment was carried out using the ultrasonic sensor widely described in [ 16 , 17 ], and modified for performing the full wave signal acquisition. The sensor itself uses the ATK 50 (Airmar) transducer, which is dedicated to operating at 50 kHz ± 4% center frequency in a pulse-echo mode.…”