Experimental study of cross-ice acoustic signal propagation

Abstract

To obtain the channel characteristics of acoustic information across ice propagation, a field experimental was conducted involving of cross-ice acoustic (CIA) direct-sequence spread spectrum communication. In the experiment, three single-component geophones installed on the surface of the ice layer were used to measure the vertical component of the particle displacement. For comparison, two hydrophones were used to measure the sound pressure for under-ice acoustic (UIA) communication. The experimental results are used to compare and analyze the characteristics of the two communication methods. This paper uses the normal model theory to calculate the acoustic signal propagation characteristics. The calculation results explain why (i) the acoustic speed of the signal received by the geophone is less than that in the water and (ii) the frequency characteristics of the UIA and CIA communication channels differ. Finally, the communication performance based on differential energy detector is analyzed, and the feasibility of CIA direct-sequence spread spectrum communication is verified.