A National Coastal Ocean Surface Current Mapping System for the United States

2004 ◽  
Vol 38 (2) ◽  
pp. 102-108 ◽  
Author(s):  
Jeffrey D. Paduan ◽  
P. Michael Kosro ◽  
Scott M. Glenn

A description is given for a nation-wide surface current mapping system for the U.S. continental shelf regions based on the emerging capabilities of high frequency (HF) radar backscatter instruments. These HF radar systems have the advantages of being real-time, non-invasive, shore-based instruments capable of mapping ocean surface currents out to ranges of ∼200 km from shore. A framework for a national backbone system is described based on long-range HF radar systems and example results are provided from existing arrays off the northwest and northeast U.S. coastlines.

1996 ◽  
Vol 101 (C12) ◽  
pp. 28615-28625 ◽  
Author(s):  
Daniel M. Fernandez ◽  
John F. Vesecky ◽  
Calvin C. Teague

Eos ◽  
2016 ◽  
Vol 97 ◽  
Author(s):  
Hugh Roarty ◽  
Lisa Hazard ◽  
Enrique Fanjul

Fourth Meeting of the Global High Frequency Radar Network; Heraklion, Crete, Greece, 22–23 September 2015


2014 ◽  
Vol 31 (7) ◽  
pp. 1564-1582 ◽  
Author(s):  
Brian M. Emery ◽  
Libe Washburn ◽  
Chad Whelan ◽  
Don Barrick ◽  
Jack Harlan

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.


2018 ◽  
Vol 56 (8) ◽  
pp. 4678-4690 ◽  
Author(s):  
Miao Li ◽  
Lan Zhang ◽  
Xiongbin Wu ◽  
Xianchang Yue ◽  
William J. Emery ◽  
...  

2017 ◽  
Vol 34 (5) ◽  
pp. 971-981 ◽  
Author(s):  
Libe Washburn ◽  
Eduardo Romero ◽  
Cyril Johnson ◽  
Brian Emery ◽  
Chris Gotschalk

AbstractA new method is described employing small drone aircraft for antenna pattern measurements (APMs) of high-frequency (HF) oceanographic radars used for observing ocean surface currents. Previous studies have shown that accurate surface current measurements using HF radar require APMs. The APMs provide directional calibration of the receive antennas for direction-finding radars. In the absence of APMs, so-called ideal antenna patterns are assumed and these can differ substantially from measured patterns. Typically, APMs are obtained using small research vessels carrying radio signal sources or transponders in circular arcs around individual radar sites. This procedure is expensive because it requires seagoing technicians, a vessel, and other equipment necessary to support small-boat operations. Furthermore, adverse sea conditions and obstacles in the water can limit the ability of small vessels to conduct APMs. In contrast, it is shown that drone aircraft can successfully conduct APMs at much lower cost and in a broader range of sea states with comparable accuracy. Drone-based patterns can extend farther shoreward, since they are not affected by the surfzone, and thereby expand the range of bearings over which APMs are determined. This simplified process for obtaining APMs can lead to more frequent calibrations and improved surface current measurements.


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Yeping Lai ◽  
Hao Zhou ◽  
Yuming Zeng ◽  
Biyang Wen

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.


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