A data processing module for acoustic doppler current meters

Abstract

This report describes the development of a Data Processing Module (DPM) designed for use with an RD Instruments Acoustic Doppler Current Meter (ADCM). The DPM is a self-powered unit in its own pressure case and its use requires no modification to the current meter. The motivation for this work was the desire for real-time monitoring and data transmission from an ADCM deployed at a remote site. The DPM serves as an interface between the ADCM and a satellite telemetry package consisting of a controller, an Argos Platform Transmit Terminal, and an antenna. The DPM accepts the data stream from the ADCM, processes the data and sends out the processed data upon request from the telemetry controller. The output of the ADCM is processed by eliminating unnecessary data combining quality control information into a small number of summary parameters, and averaging the remaining data in depth and time. For the implementation described here, eight data records of 719 bytes each, output from the ADCM at 15 minute intervals, were processed and averged over 2 hr intervals to produce a 34 byte output array.