Trends in acoustic velocity log technology at RD Instruments

RD Instruments (RDI) has been the leading manufacturer of acoustic Doppler current profilers (ADCP) for many years. Sales of our products for use primarily as navigation sonars or Doppler velocity logs (DVL) have been limited until recently by issues of size, weight, and cost. In 1995, RDI introduced the Workhorse product line which dramatically reduced the size, weight, and cost of ADCPs. This was followed closely by the Navigator DVLs which are based on the same technology. The Navigators have received an excellent reception by the small AUV community and are in use on many of the prominent vehicles in the world today. In addition to AUV builders, the ROV community is beginning to discover the value of incorporating a DVL into the vehicle's navigation and control system. In this paper, we discuss some of the applications in which our DVLs are being used and the technical issues which have been addressed. We also present our views on the directions in which the acoustic velocity log technology is moving and some of the constraints on that technology. The issues discussed include further reduction of size, weight and cost, the use of phased array technology to reduce further the transducer size, and the progress which we have made in correlation velocity logs as a deep water alternative to DVLs.