Long range current measurement from a surface buoy in the Gulf of Mexico

Abstract

Since the early 2000s, long range (> 600 m) Acoustic Doppler Current Profilers (ADCPs) have been widely used in the Gulf of Mexico in connection with the Oil and Gas industry. These ADCPs have been mounted almost exclusively on large, stable offshore platforms. In this paper we present data from an ongoing, multi-year deployment of such a system, but instead mounted under a dynamically moving surface buoy. Unlike installations on fixed platforms, surface buoys present additional challenges to ADCP data given their dynamic motion's negative impact on the velocity data quality [1]–[3]. This presents further complexities specific to long range ADCPs due to their acoustic pulse's inherently longer two-way travel times (when compared to short range ADCPs). This present work describes some of these challenges and presents data over a three year period in view of them, offering an analysis of the data quality and instrument performance, including comparison with a nearby platform-mounted ADCP indicating that surface buoy-mounted long range profilers are an acceptable and viable alternative to fixed platform-mounted ADCPs.