Ocean Surface Current Measurement Using Shipborne HF Radar: Model and Analysis

2016 ◽  
Vol 41 (4) ◽  
pp. 970-981 ◽  
Author(s):  
Guanghong Chang ◽  
Ming Li ◽  
Junhao Xie ◽  
Ling Zhang ◽  
Changjun Yu ◽  
...  
Keyword(s):  
Surface Current ◽  
Ocean Surface ◽  
Current Measurement ◽  
Hf Radar ◽  
Ocean Surface Current

Measuring Antenna Patterns for Ocean Surface Current HF Radars with Ships of Opportunity

2014 ◽  
Vol 31 (7) ◽  
pp. 1564-1582 ◽  
Author(s):  
Brian M. Emery ◽  
Libe Washburn ◽  
Chad Whelan ◽  
Don Barrick ◽  
Jack Harlan
Keyword(s):  
Surface Current ◽  
Ocean Surface ◽  
Radar Data ◽  
Direction Finding ◽  
Antenna Pattern ◽  
Hf Radar ◽  
Ocean Current ◽  
Identification System ◽  
Screening Methods ◽  
Ocean Surface Current

Abstract HF radars measure ocean surface currents near coastlines with a spatial and temporal resolution that remains unmatched by other approaches. Most HF radars employ direction-finding techniques, which obtain the most accurate ocean surface current data when using measured, rather than idealized, antenna patterns. Simplifying and automating the antenna pattern measurement (APM) process would improve the utility of HF radar data, since idealized patterns are widely used. A method is presented for obtaining antenna pattern measurements for direction-finding HF radars from ships of opportunity. Positions obtained from the Automatic Identification System (AIS) are used to identify signals backscattered from ships in ocean current radar data. These signals and ship position data are then combined to determine the HF radar APM. Data screening methods are developed and shown to produce APMs with low error when compared with APMs obtained with shipboard transponder-based approaches. The analysis indicates that APMs can be reproduced when the signal-to-noise ratio (SNR) of the backscattered signal is greater than 11 dB. Large angular sectors of the APM can be obtained on time scales of days, with as few as 50 ships.

scholarly journals Ocean Surface Current Observation with a Dual Monopole-Cross-Loop Antenna Array

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Yeping Lai ◽  
Hao Zhou ◽  
Yuming Zeng ◽  
Biyang Wen
Keyword(s):  
Antenna Array ◽  
Surface Current ◽  
Ocean Surface ◽  
Antenna System ◽  
Current Measurement ◽  
Current Profile ◽  
Current Observation ◽  
Ocean Surface Currents ◽  
Ocean Surface Current

The high-frequency radars (HFRs) receiving the sea echoes backscattered from the fluctuating ocean surface to remotely sense ocean surface currents are a popular and powerful tool in oceanic observation. Dominant error source in current measurement for HFR systems has been recognized to be the direction of arrival (DOA) determination of the sea echoes. To eliminate this error and therefore improve the performance of direction-finding HFR system in current measurement, we have investigated a dual monopole-cross-loop (MCL) antenna array in current observation. Simulations indicated that the dual MCL antenna array has a better performance than the conventional single MCL antenna system in current mapping, especially for the complex current profile. And comparisons of radar field data and buoy measurements suggested that the RMSE value was larger than 15 cm/s for the conventional MCL antenna. But it decreased to 12.64 cm/s for the dual MCL antenna array. Moreover, the temporal coverage rate also showed the benefit of using this antenna system in current mapping. The results demonstrated that it is advisable to adopt the dual MCL antenna array in operational applications.

Simulation of tsunami signatures in ocean surface current maps measured by HF radar

2009 ◽  
Author(s):  
Anna Dzvonkovskaya ◽  
Klaus-Werner Gurgel ◽  
Thomas Pohlmann ◽  
Thomas Schlick ◽  
Jiangling Xu
Keyword(s):  
Surface Current ◽  
Ocean Surface ◽  
Hf Radar ◽  
Ocean Surface Current

Ocean surface current measurement with high-frequency hybrid sky–surface wave radar

2017 ◽  
Vol 8 (7) ◽  
pp. 617-626 ◽  
Author(s):  
Yonggang Ji ◽  
Jie Zhang ◽  
Xiaoliang Chu ◽  
Yiming Wang ◽  
Longquan Yang
Keyword(s):  
Surface Wave ◽  
High Frequency ◽  
Surface Current ◽  
Ocean Surface ◽  
Current Measurement ◽  
Wave Radar ◽  
Ocean Surface Current

scholarly journals Applying the Method of EOF Interpolation and 2dVar to Complete the Ocean Surface Current Data Obtained from HF Radar System

2018 ◽  
Vol 34 (1S) ◽  
Author(s):  
Nguyen Thi Thu Mai ◽  
Alexei Sentchev ◽  
Tran Manh Cuong
Keyword(s):  
Interpolation Method ◽  
Surface Current ◽  
Ocean Surface ◽  
Radar Data ◽  
Current Data ◽  
Surface Flow ◽  
Radar System ◽  
Hf Radar ◽  
High Frequency Radar ◽  
Ocean Surface Current

Abstract: There are now over 350 high frequency radar (HF radar) stations operating on the coast of 37 countries around the world that allow the mapping of ocean surface current. However, observation from HF radars are often interrupted (loss of data) in both space and time due to signal inference, backscatters, ocean state.Therefore, in this study, we will present a method to improve the surface current data collected from HF radar system. Firstly, the radial surface current data will be filtered intermittently, then the result is interpolated over time and space by the orthogonal experimental EOF and the 2dVar bi-directional variable interpolation. In addition, the authors have initially applied 2dVar interpolation method to the HF radar data in Vietnam and received initial positive results. The methods used in this paper promise to be effective when applied to improve surface flow data obtained from HF radar stations in Vietnam in the future.   Keywords:EOF interpolation, 2dVar, Iroise sea, HF radar, ocean surface current.

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