A new retroreflector named "quatriplan" based on the corner-cube principle, for advanced ultrasonic telemetry...

Telemetry consists in remotely detecting and locating an object. For applications in immersed structures as in nuclear primary vessel, ultrasonic waves are well adapted. Moreover, fixing a target on the structures of interest maximizes the signal-to-noise ratio and provides a reference point. Classical Corner-Cube Retroreflector (CCR) demonstrated high performance in this framework (1D and 2D measurements) but does not allow knowing the full (3D) positioning of the structure. This paper proposes an innovative compact target named "quatriplan", based on the CCR principle, and which must allow the ability to determine the orientation of the target in addition to its distance to the transducer. The simple design of the quatriplan is first explained, then its performances are investigated with modelling and experimentations. The results highlight its strong performance and benefit for advanced telemetry applications in industrial systems where complex design can impede easy and efficient access for inspection of specific parts.