scholarly journals On the Reliability of Surface Current Measurements by X-band Marine Radar

2019 ◽  
Vol 11 (9) ◽  
pp. 1030 ◽  
Author(s):  
Hessner ◽  
El Naggar ◽  
von Appen ◽  
Strass
Keyword(s):  
Real Time ◽  
Surface Current ◽  
Acoustic Doppler Current Profiler ◽  
Weather Conditions ◽  
Operational Reliability ◽  
Current Data ◽  
X Band ◽  
Current Profiler ◽  
Marine Radar ◽  
Commercial Off The Shelf

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® II (WaMoS® II) deployed onboard the German Research vessel Polarstern. The measurement reliability is specified by an IQ value obtained by the WaMoS® 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® II accuracy was carried out based on sliding means over 20 min of the reliable data only. The associated standard deviation σWaMoS = 0.02 m/s of the mean WaMoS® 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® II/ADCP northward and eastward velocity data pairs yield a correlation of r ≥0.94, with bias∆ ≤0.06 m/s and σS=0.05 m/s. This confirms that the MR-based surface current measurements are accurate and reliable.

Stratifikasi Massa Air di Teluk Lasolo, Sulawesi Tenggara

2016 ◽  
Vol 1 (2) ◽  
pp. 17
Author(s):  
Dewi Surinati ◽  
Edi Kusmanto
Keyword(s):  
North Pacific ◽  
Water Mass ◽  
Acoustic Doppler Current Profiler ◽  
Current Data ◽  
Water Masses ◽  
Intermediate Water ◽  
North Pacific Intermediate Water ◽  
Conservation Area ◽  
Current Profiler ◽  
Salinity Data

<strong>Stratification of Water Mass in Lasolo Bay, Southeast Sulawesi.</strong> As a nature conservation area, Lasolo Bay should be supported by data and information of waters oceanographic. Research for stratification of water masses in Lasolo Bay was conducted. from 10 to 19 July 2011. Temperature and salinity data were obtained using CTD SBE 911 Plus preinstalled on Research Vessel Baruna Jaya VIII at intervals of 24 data per second. Current data were obtained using Vessel Mounted Acoustic Doppler Current Profiler (VMADCP) with an interval of two seconds. The results show that there are differences in the speed and direction of currents in the water column that lead to stratification of water masses. Currents that drove the water mass of Banda Sea into Lasolo Bay was caused by southeasterly winds with an average speed of 4.1 m/s. At depths of 0–50 m and 100–200 m the current dominance occurs to the northwest, while at depths of 50–100 m and 200–350 m it occurs to the south. The water mass with a salinity of 32.1–34.0 PSU and temperature 26–28°C occupied the surface layer (0–50 m). The water mass with a salinity of 34.4–34.5 PSU identified as the water mass of North Pacific Intermediate Water (NPIW) occupied two depths, i.e. 50–100 m and 200–350 m with different range of temperatures. The water mass with maximum salinity (34.5–34.6 PSU), identified as the water mass of North Pacific Subtropical Water (NPSW) also occupied two depths i.e. 100–200 m and 350 m until near the bottom with different range of temperatures<br /><br />

A High-Latitude Modular Autonomous Power, Control, and Communication System for Application to High-Frequency Surface Current Mapping Radars

2011 ◽  
Vol 45 (3) ◽  
pp. 59-68 ◽  
Author(s):  
Hank Statscewich ◽  
Tom Weingartner ◽  
Seth Danielsen ◽  
Bruno Grunau ◽  
Greg Egan ◽  
...  
Keyword(s):  
Real Time ◽  
High Frequency ◽  
Performance Monitoring ◽  
Surface Current ◽  
Satellite Communications ◽  
Current Data ◽  
Power Performance ◽  
Time Data ◽  
Power Module ◽  
Remote Sites

AbstractHigh-frequency, shore-based radars (HFR) collect hourly, real-time surface current data over broad areas of the coastal ocean and yield insights on time-varying circulation, predict oil spill trajectories, evaluate circulation models, and, in case of a spill, provide responders with real-time data on spill evolution. HFR requires 7.5 kWh/day of power, but the lack of power availability inhibits HFR use in Alaska. We developed a modular, autonomous remote power module (RPM) for Arctic environments. The RPM design facilitates setup and transport to remote sites using small vehicles, and it contains subsystems for power generation, satellite communications, and power performance monitoring. The subsystems are powered by a battery bank (with a 5-day power reserve) charged primarily by wind and solar and secondarily by a biodiesel generator. The RPM is a stand-alone device for long-term deployments. It minimizes permit issues associated with diesel generators and logistics costs associated with refueling and maintenance. Performance data from a prototype RPM setup in Barrow, Alaska, in fall 2010 is provided. The system is designed for high latitudes but can be modified for remote coasts elsewhere.

Sea-State Monitoring Via X-Band Marine Radar Images Sequences: A New Approach for an Accurate Surface Currents Estimation

2009 ◽  
Author(s):  
Francesco Serafino ◽  
Claudio Lugni ◽  
Francesco Soldovieri
Keyword(s):  
Synthetic Data ◽  
Surface Current ◽  
Key Factors ◽  
State Monitoring ◽  
Sea State ◽  
Reconstruction Procedure ◽  
Factors Affecting ◽  
Radar Images ◽  
X Band ◽  
Marine Radar

This work deals with the sea state monitoring starting from marine radar images collected on a moving ship. For such a topic, one of the key factors affecting the reliability of the reconstruction procedure is the determination of the equivalent surface current that also accounts for the speed of the moving ship. Here, we propose a method able to evaluate also high values of the sea surface current. The reliability of the proposed procedure is shown by a numerical analysis with synthetic data. Finally, we present some preliminary results with measurements collected on a moving ship.

scholarly journals X-Band Radar for the Monitoring of Sea Waves and Currents: A Comparison between Medium and Short Radar Pulses

2017 ◽  
Author(s):  
Giovanni Ludeno ◽  
Francesco Raffa ◽  
Francesco Soldovieri ◽  
Francesco Serafino
Keyword(s):  
Surface Current ◽  
Parameters Estimation ◽  
Sea Waves ◽  
State Monitoring ◽  
Sea State ◽  
Experimental Campaign ◽  
X Band ◽  
Waves And Currents ◽  
Marine Radar ◽  
Good Agreement

Abstract. This letter presents the monitoring results of the sea waves and the surface currents obtained by analyzing data acquired by a X-band marine radar in two different operative conditions, namely the short and medium pulse modes. In particular, we investigated the feasibility to use a medium radar pulse for sea state monitoring by comparing the performance in both the radar modes. The comparison was carried out by means of an experimental campaign and we observed a good agreement for surface current and sea state parameters estimation.

scholarly journals Current Patterns in the Inner Sound (Pentland Firth) from Underway ADCP Data*

2013 ◽  
Vol 30 (1) ◽  
pp. 96-111 ◽  
Author(s):  
Lonneke Goddijn-Murphy ◽  
David K. Woolf ◽  
Matthew C. Easton
Keyword(s):  
Acoustic Doppler Current Profiler ◽  
Tidal Energy ◽  
Current Data ◽  
Northern Coast ◽  
Orkney Islands ◽  
The North ◽  
Tidal Changes ◽  
Current Profiler ◽  
Tidal Stream ◽  
Tidal Streams

AbstractNumerous acoustic Doppler current profiler (ADCP) surveys were performed in the Inner Sound of the Pentland Firth, a channel between the Orkney Islands and the northern coast of Scotland connecting the Atlantic Ocean to the west and the North Sea to the east. The Pentland Firth has the highest tidal streams of the British Isles, and one of the highest that can be found around the globe. Here, the tidal energy industry is in its demonstration phase, but not many real current measurements are in the public domain. The authors present real current data, measured during different phases of the tidal cycle, using a vessel-mounted ADCP. The tidal changes can be rapid, and because the underway measurements take time, the apparent spatial patterns are affected by temporal variation. A method is described that estimated and corrected this temporal distortion using a hydrodynamic model. It appeared that ebb and flood streams did not fully overlap, and that the tidal streams were more complicated, turbulent, and variable than existing models suggest. The data were analyzed for characteristics pertinent to practical tidal stream energy exploitation, and two favorable sites in the Inner Sound are identified. All original current data are available from the British Oceanographic Data Centre (BODC).

Wind on lakes brings predator and prey together in the pelagic zone

2015 ◽  
Vol 72 (11) ◽  
pp. 1652-1662 ◽  
Author(s):  
Derrick Tupper de Kerckhove ◽  
Edyta Agnes Blukacz-Richards ◽  
Brian John Shuter ◽  
Liset Cruz-Font ◽  
Peter Arnold Abrams
Keyword(s):  
Aquatic Ecosystems ◽  
Large Range ◽  
Spatial Scales ◽  
Acoustic Doppler Current Profiler ◽  
Weather Conditions ◽  
Trophic Levels ◽  
Stratified Lakes ◽  
Water Currents ◽  
Current Profiler ◽  
Calm Weather

Wind blowing over the pelagic zones of stratified lakes creates recirculating water currents. In Lake Opeongo, we observed the effects of these currents on four different trophic levels using a variety of methods (acoustic Doppler current profiler, optical plankton counter, hydroacoustics, telemetry, and netting programs). During windy events, (1) water currents were stronger than the known swimming speeds of small zooplankton (355 to 399 μm) but not larger species or fish, (2) large zooplankton (>542 μm) and schooling planktivores congregated at the thermocline at the downwind end of the basin, and (3) large piscivores directed their foraging towards areas exposed to wind, where they appeared to acquire the same meal as under calm weather conditions but with less effort. We propose that (i) the horizontal physical homogeneity of pelagic zones, (ii) the slow swimming ability of zooplankton relative to the speed of wind-induced water currents, and (iii) the likely growth benefits to predators of foraging on patches of prey lead to the downwind aggregation of pelagic organisms. We discuss this conceptual framework with examples from both lake and ocean ecosystems to suggest that this phenonenon occurs across a large range of spatial scales in aquatic ecosystems.

Optimizing and Validating High-Frequency Radar Surface Current Measurements in the Mona Passage

2011 ◽  
Vol 45 (3) ◽  
pp. 49-58 ◽  
Author(s):  
Jorge E. Corredor ◽  
Andre Amador ◽  
Miguel Canals ◽  
Samuel Rivera ◽  
Jorge E. Capella ◽  
...  
Keyword(s):  
High Frequency ◽  
Surface Current ◽  
Acoustic Doppler Current Profiler ◽  
The United States ◽  
Repeated Measurements ◽  
Surface Velocity ◽  
High Frequency Radar ◽  
Detection And Tracking ◽  
Current Profiler ◽  
Mona Island

AbstractThe Mona Passage is a major shipping lane to the Panama Canal and a key route for illegal traffic into the United States. We have emplaced two high-frequency radar (HFR) stations on the west coast of Puerto Rico intended to allow mapping of the ocean surface velocity field of the eastern Mona Passage and to explore its performance in vessel detection and tracking. The array provides coverage of the southeastern quadrant of the Passage extending west to Mona Island and north to Rincon. Hourly results are posted online in near-real time. To optimize our results, we twice measured the antenna beam patterns and applied these corrections to the resulting radial returns. To assess the basic capability of the Mona Passage HFR array to measure surface currents in this tropical environment, we undertook validation measurements, including repeated deployment of Lagrangian drifters, deployment of an acoustic Doppler current profiler, and comparison with modeled tidal currents. Our experimental measurements showed good agreement to both modeled and in situ data lending confidence to the area-wide surface current maps generated by this system. Repeated measurements showed limited temporal variability of antenna distortion patterns, demonstrating that these are in large part the product of the surrounding environment. Comparison between a numerical particle tracking algorithm and experimental Lagrangian trajectories showed mixed results, with better agreement during periods of low intrahour variability in current direction than during periods of rapid tidal reversal.

Dynamics Analysis of ADCP Carrier and its Mooring System

2013 ◽  
Vol 819 ◽  
pp. 150-154
Author(s):  
Zhen Jiang Yu ◽  
Yuan Dai ◽  
Peng Huang ◽  
Xiao Peng Zhang ◽  
Zong Yu Chang
Keyword(s):  
Acoustic Doppler Current Profiler ◽  
External Flow ◽  
Current Data ◽  
Mooring System ◽  
Ocean Engineering ◽  
Oceanographic Research ◽  
Sea Current ◽  
Current Profiler ◽  
Fluent Software ◽  
Effective Instrument

Acoustic Doppler Current Profiler (ADCP) is one effective instrument to measure the sea current and is widely utilized in oceanographic research and ocean engineering. Some structure or frame is utilized to carry or hold ADCP in mooring system. This paper studies the hydrodynamics of different kinds of ADCP carriers and the motion of mooring system with ADCP carriers. By applying Fluent software external flow field of ADCP carrier is analyzed. Meanwhile, the velocity distribution and pressure distribution are obtained. Drag coefficients of ADCP carrier are used to analyze the mechanics and profile of mooring system with ADCP. Designing the ADCP carrier and mooring system is very useful which can provide theoretic basis for current data analysis.

Comparative Evaluation of Volumetric Current Measurements in a Tidally Dominated Coastal Setting: A Virtual Field Experiment

2020 ◽  
Vol 37 (4) ◽  
pp. 533-552
Author(s):  
Trevor Harrison ◽  
Kristen M. Thyng ◽  
Brian Polagye
Keyword(s):  
High Resolution ◽  
Puget Sound ◽  
Acoustic Doppler Current Profiler ◽  
Hydrodynamic Simulation ◽  
X Band ◽  
Virtual Field ◽  
Current Profiler ◽  
Short Time ◽  
Scalar Properties

AbstractHigh-resolution, four-dimensional mapping of currents in tidally dominated coastal settings can be conducted with a range of instrumentation. Here, we assess four approaches to data collection: an X-band radar, a stationary (bottom mounted) acoustic Doppler current profiler (ADCP), a mobile (vessel based) ADCP, and a swarm of Lagrangian floats. Using the output from a hydrodynamic simulation, a virtual field campaign was performed at 24 locations in Admiralty Inlet, Puget Sound, Washington, during spring and neap tidal exchanges. A reconstruction of the volumetric currents was generated for each platform every 15 min and evaluated against the true currents to assess accuracy over a horizontal extent of 400 m × 500 m at 5 m resolution and vertically through the entire water column (20–80 m) at 2 m resolution. Results demonstrate that, for this survey extent and resolution, a vessel-based ADCP survey is most accurate, followed closely by the float swarm. The overall performance hierarchy persists over most locations and times. Thus, if mapping currents at high resolution (<10 m) and short time scales (<1 day) is the primary scientific objective, vessel-based ADCP surveys are likely the best option. For longer-duration surveys, a combined deployment with a stationary ADCP and X-band radar system is the best choice. Last, if in situ measurements of scalar properties (e.g., salinity, temperature, dissolved oxygen) are also desired, float swarms can simultaneously sample these while surveying currents with accuracy comparable to mobile ADCPs.

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