On the Reliability of Surface Current Measurements by X-Band Marine Radar

Real-time quality-controlled surface current data derived from X-Band marine radar (MR) measurements were evaluated to estimate their operational reliability. The presented data were acquired by the standard commercial off-the-shelf MR-based sigma s6 WaMoS((R)) II (WaMoS((R)) II) deployed onboard the German Research vessel Polarstern. The measurement reliability is specified by an IQ value obtained by the WaMoS((R)) II real-time quality control (rtQC). Data which pass the rtQC without objection are assumed to be reliable. For these data sets accuracy and correlation with corresponding vessel-mounted acoustic Doppler current profiler (ADCP) measurements are determined. To reduce potential misinterpretation due to short-term oceanic variability/turbulences, the evaluation of the WaMoS((R)) II accuracy was carried out based on sliding means over 20 min of the reliable data only. The associated standard deviation <mml:semantics>sigma WaMo0.02 m/s of the mean WaMoS((R)) II measurements reflect a high precision of the measurement and the successful rtQC during different wave, current and weather conditions. The direct comparison of 7272 WaMoS((R)) II/ADCP northward and eastward velocity data pairs yield a correlationm/s. This confirms that the MR-based surface current measurements are accurate and reliable.