RiverRay ADCP: Performance of a shallow water phased array ADCP

Phased array ADCPs have been used for oceanography since the mid-1990´s. Phased array technology for ADCPs allows the physical size of a low frequency ADCP to be significantly reduced by generating four acoustic beams from a single transducer. Until recently, acoustic phased arrays were built from individual transducer elements: this method did not allow construction at higher frequencies since the discrete array elements would be on the order of a millimeter in lateral and vertical dimensions, making the assembly of a larger transducer impractical. This problem was solved by dicing a single piezoelectric into small elements to produce a precision array. The RiverRay ADCP is the first phased array ADCP specifically designed for shallow water velocity profiling. In addition to the phased array transducer, it incorporates several unique features for use in shallow water, particularly for river discharge measurement. This paper discusses the RiverRay ADCP and its performance in the field.