Monostatic radio-acoustic sounding system

Practical radar-acoustic sounding systems (RASS) generally employ a bistatic scheme with the radar source and receiver placed symmetrically beside the acoustic radiator. This paper presents a novel method for combining the acoustic and the electromagnetic waves which reduces complexity, size and cost of the system and enhances portability. Another advantage of a monostatic PASS is that only one HF-antenna is needed. Because of that circumstance no dead zone exists in front of the system. Two possible solutions for realizing a monostatic system are taken into account. The first approach uses a dielectric plate to redirect the acoustic wave. By the second solution the electromagnetic wave is directed into the ultrasonic propagation by a wire grid. As no frequency limits exist for the monostatic RASS it is possible to use the usual PASS frequency at 915 MHz or 1290 MHz for the electromagnetic wave. Measurements show that a maximum distance of 30 m can be reached with uncertainties of +-5 mm at 10 GHz for ranging measurements