The Design of a Transmitter with a Parabolic Conical Reflector for a Sonar Ring

Sonar rings are composed of many ultrasonic receivers arranged in a ring and have in the past used many transmitters. The transmitters have been fired either serially or together and the receivers measure time-of-flight to reflectors in the environment. Serial transmission reduces the measurement rate around the entire ring, whilst parallel transmission incurs interference problems between neighbouring transmitters. This paper describes a new design employing a single high powered transmitter available from Murata (ESTD01 Super Tweeter) and a parabolic conical reflector that overcomes both these issues. The reflector is designed to narrow the vertical beamwidth of the transmitter and to provide good dispersion of the sound around the ring. The paper details the design, TLM simulation and measurements that characterise the performance, such as the intensity compared to previous systems, the elevation beamwidth and the pulse shape.