A5046181871- Ocean Waves and Remote Sensing
- Oceanographic and Atmospheric Processes
- Radar Systems and Signal Processing
- Underwater Acoustics Research
- Coastal and Marine Dynamics
- GNSS positioning and interference
- Ionosphere and magnetosphere dynamics
- Meteorological Phenomena and Simulations
- Tropical and Extratropical Cyclones Research
- Arctic and Antarctic ice dynamics
- Geophysics and Gravity Measurements
- Radio Wave Propagation Studies
- Marine and coastal ecosystems
- Advanced SAR Imaging Techniques
- Seismic Imaging and Inversion Techniques
- Electromagnetic Scattering and Analysis
- Electromagnetic Launch and Propulsion Technology
- Soil Geostatistics and Mapping
- Methane Hydrates and Related Phenomena
- Seismic Waves and Analysis
- Plasma Diagnostics and Applications
- Marine and coastal plant biology
- Scientific Research and Discoveries
- Ultra-Wideband Communications Technology
- Marine and environmental studies
University of Sheffield
2014-2023
SeaView Research
2021
James Cook University
2012-2018
Queen Mary University of London
2014
National Centre for Earth Observation
1997-2008
Universität Hamburg
2002
MSD (Spain)
2002
Max Planck Society
2002
Sheffield Hallam University
2002
OceanWaveS (Germany)
2002
Academic, government, and private organizations from around the globe have established High Frequency radar (hereinafter, HFR) networks at regional or national levels. Partnerships been to coordinate collaborate on a single global HFR network (http://global-hfradar.org/ ). These partnerships were in 2012 as part of Group Earth Observations (GEO) promote technology increase data sharing among operators users. The main product are continuous maps ocean surface currents within 200 km coast high...
High Frequency radar (HFR) is a land-based remote sensing instrument offering unique insight to coastal ocean variability, by providing synoptic, high frequency and resolution data at the atmosphere interface. HFRs have become invaluable tools in field of operational oceanography for measuring surface currents, waves winds, with direct applications different sectors an unprecedented potential integrated management zone. In Europe, number HFR networks has been showing significant growth over...
This paper presents results of a trial Pisces HF radar system aimed at assessing its use as component wave-monitoring network being installed around the coasts England and Wales. The has been operating since December 2003 continued to June 2005. data have processed in near-real time displayed on website. Radar measurements directional spectrum derived parameters are compared with those measured waverider products from Met Office, United Kingdom, operational wave model. currents winds also...
Abstract The Chahine-Twomey relaxation method for inversion of the atmospheric radiative transfer equation is extended to provide an inverse solution Barrick's describing second order scatter high frequency (HF) radio waves from ocean surface. success demonstrated here using synthesised radar Doppler spectra obtained by solving direct problem with wave buoy directional spectrum measurements. Wave measurements are limited in range characteristics that can be measured. results presented...
High-frequency surface wave radar (HFSWR) has been widely adopted as a useful remote-sensing tool for sea-state monitoring. There are limitations to the performance because of various unwanted clutters and interferences that contaminate signals. Among all types signals, radio frequency interference (RFI) is dominant since bands 3–30 MHz, operation range HFSWR, shared by many services. If RFI occupies areas in Doppler spectrum essential estimation oceanographic parameters, example, wind...
The power spectrum of backscatter from the ocean surface at HF radio frequencies is characterized by two large peaks called first-order Bragg peaks. These are surrounded a continuum due to second-order effects. can be described in low moderate sea states nonlinear integral equation relating it wave directional spectrum. Inverting this provides an estimate A number inversion methods have been published. In paper, Wyatt method discussed. This uses part that surrounds larger peak. An extension...
Abstract In recent decades, high‐spatial resolution ocean radar and satellite imagery measurements have revealed a complex tangle of submesoscale filaments eddies, in the surface velocity, temperature, chlorophyll fields. We use suite high‐resolution data to characterize two counter‐rotating, short‐lived eddies formed at front between warm East Australian Current (EAC) temperate coastal waters (30°S, Eastern Australia). this region, are dynamically generated decay time scales hours days....
AbstractThe interpretation of high-frequency (HF) radar backscatter from the sea surface to provide measurements waves, winds, and currents has been developing over last 30 years. Dual systems are usually used because it is then possible resolve direction amplitude ambiguities in wave wind measurement full vector currents. In this paper accuracy limitations with single explored using data sets obtained a number experiments dual systems. It shown that estimates significant height, mean...
A model‐fitting technique to extract the ocean long wave directional spectrum from Doppler of HF backscatter sea surface is described here. This an extension one developed by Lipa and Barrick [1982] extends frequency range that can be measured using radar frequencies in lower (6‐18 MHz). Results application this a wide variety simulated spectra are presented which demonstrate some weaknesses method as well its strengths. The predicts accurate estimates longwave amplitude all components...
Abstract The Barrick–Weber equations describe the interaction of radar signals with dynamic ocean surface, and so provide a mathematical basis for oceanic remote sensing. This report considers inversion these several row-action methods commonly used to solve large linear systems unstructured sparsity. It is found that performance in inverting both synthetic measured Doppler spectral data comparable, method Chahine–Twomey–Wyatt offering slight advantage reliability recovery full directional...
Abstract The accuracy of wave direction and spreading at the Bragg-matched wavelength measured with HF radar over a wide range operating frequencies is demonstrated by comparison buoy data. agreement for shortwave better than that obtained wind direction, which has been more common application this measurement, because these waves are not always aligned particularly in short fetch low speed situations. method assumes model directionality validity explored using Fourier coefficients,...
Abstract Ocean Surface Current Radar (OSCR) HF radar measurements of ocean waves and currents were made during the Shoaling Waves Experiment (SHOWEX) in fall 1999. During some periods, at locations, good quality wave obtained. Limitations measurement capability due to OSCR hardware, deployment configuration, signal-to-noise ratio, antenna sidelobes are identified discussed. A short period large presence pattern distortion is as source main errors measurements.
Surface velocity data from two WERA high-frequency (HF) ocean radar systems, deployed as part of the Australian Integrated Marine Observing System (IMOS), are compared with near-surface currents obtained drifters and acoustic Doppler current profilers (ADCPs). We evaluate contrasting locations in first detailed evaluation IMOS HF surface velocities. measurements generally robust but demand quality-control procedures to eliminate obvious errors outliers that appear temporarily or...
The maximum-likelihood method is used to extract parameters of two-parameter models the directional spreading short wind waves from power spectrum high-frequency (HF) radar backscatter. have a wavelength half radio that, for data presented here, at frequency 0.53 Hz. are short-wave direction, which this can be identified with and spread angle, parameterization model dependent. For results suggest that Donelan provides better description than coss model. HF wave buoy measurements compared...
This study compares current measurements between HF WERA radar and Acoustic Doppler Current Profilers (ADCPs) in Liverpool Bay using a two-year time series from 2006 to 2008. Radar are shown agree well with those of ADCPs, having directional differences less than 3°, amplitude correlations greater 0.93, small root mean square differences. Using Least Squares Harmonic Analysis for tidal decomposition best capture surface effects.The effects the North Hoyle wind farm on measurement accuracy...
HF radars are now an important part of operational coastal observing systems where they used primarily for measuring surface currents. Their use wave and wind direction measurement has also been demonstrated. These measurements based on physical models radar backscatter from the ocean described in terms its directional spectrum influence thereon current. Although this contains information about local that is generating sea spectrum, it includes spectral components propagating into area...
Abstract High frequency radar measurements of significant waveheight during two experiments in the Celtic Sea are discussed. A new algorithm has been developed which can be used to provide with accuracies about 12 per cent relative wave-buoy measurements. dual-radar system is required for this measurement. For use a single-radar system, some additional information on directional properties wave spectrum required.