scholarly journals Quality Assessment and Practical Interpretation of the Wave Parameters Estimated by HF Radars in NW Spain

2020 ◽  
Vol 12 (4) ◽  
pp. 598 ◽  
Author(s):  
Ana Basañez ◽  
Pablo Lorente ◽  
Pedro Montero ◽  
Enrique Álvarez-Fanjul ◽  
Vicente Pérez-Muñuzuri
Keyword(s):  
Hf Radar ◽  
Wave Direction ◽  
Nw Spain ◽  
Wave Regime ◽  
Wave Data ◽  
Wave Parameters ◽  
Range Cell ◽  
Wave Reanalysis ◽  
Radar Wave ◽  
Sampling Times

High-frequency (HF) radars are efficient tools for measuring vast areas and gathering ocean parameters in real-time. However, the accuracy of their wave estimates is under analysis. This paper presents a new methodology for analyzing and validating the wave data estimated by two CODAR SeaSonde radars located on the Galician coast (NW Spain). Approximately one and a half years of wave data (January, 2014–April, 2015) were obtained for ten range cells employing two different sampling times used by the radar software. The resulting data were screened by an updated method, and their abundance and quality were described for each radar range cell and different wave regime; the latter were defined using the spectral significant wave height (Hm0) and mean wave direction (Dm) estimated by two buoys and three SIMAR points (SImulación MARina in Spanish, from the wave reanalysis model by Puertos del Estado (PdE)). The correlation between the results and the particularities of the different sea states (broadband or bimodal), the wind and the operation of the devices are discussed. Most HF radar wave parameters’ errors occur for waves from the NNE and higher than 6 m. The best agreement between the Vilán radar and the Vilano-Sisargas buoy wave data was obtained for the dominant wave regime (from the northwest) and the southwest wave regime. However, relevant contradictions regarding wave direction were detected. The possibilities of reducing the wave parameters’ processing time by one hour and increasing the numbers of range cells of the radars have been validated.

Data assimilation of partitioned HF radar wave data into Wavewatch III

2013 ◽  
Vol 72 ◽  
pp. 17-31 ◽  
Author(s):  
Jennifer Waters ◽  
Lucy R. Wyatt ◽  
Judith Wolf ◽  
Adrian Hines
Keyword(s):  
Data Assimilation ◽  
Hf Radar ◽  
Wavewatch Iii ◽  
Wave Data ◽  
Radar Wave

scholarly journals A Wave Measurements HF Radar Data Set in the Malta-Sicily Channel: Data Quality, Validation and Gap Filling

10.29007/wg8s ◽  
2018 ◽  
Author(s):  
Marco Picone ◽  
Arianna Orasi ◽  
Aldo Drago ◽  
Fulvio Capodici ◽  
Giuseppe Ciraolo ◽  
...  
Keyword(s):  
Wave Height ◽  
Significant Wave Height ◽  
Missing Values ◽  
Hf Radar ◽  
Data Set ◽  
Significant Wave ◽  
Wave Data ◽  
Wave Measurements ◽  
Sicily Channel ◽  
Radar Wave

The CALYPSO HF radar network is a permanent and fully operational observing system currently composed of four CODAR HF stations. The system is providing real- time hourly maps of sea surface currents and wave data in the Malta-Sicily Channel since 2012. Significant wave height derived from the HF radar wave measurements are confirmed to be a reliable source of wave information even in case of extreme events. However, it is noticed that the HF radar wave data are subject to differing interfering noise in the signal from unknown sources that may be competing with transmissions in the same frequency band. These interferences lead to frequent gaps and/or outliers that affect the continuity and reliability of the data set. The aim of this work is to estimate missing values and to detect possible outliers building and fitting a Markov chain mixture model on the significant wave height data collected at the four stations. It is verified that the proposed procedure is sufficiently robust since the model estimates succeed to classify radar observations with a high percentage of missing data and to equally highlight spikes and outliers.

Long-Term Wave Measurement by an Onboard Radar Wave Meter and Prediction of Ship Motions Based on the Onboard Wave Measurements

2015 ◽  
Author(s):  
Hisafumi Yoshida ◽  
Hideo Orihara ◽  
Keiichi Yamasaki
Keyword(s):  
Ship Motions ◽  
Observation Data ◽  
Wave Direction ◽  
Motion Data ◽  
Safe Navigation ◽  
Wave Data ◽  
Wave Measurements ◽  
Short Term Prediction ◽  
Radar Wave

Continuous measurement of waves, ship motions (roll and pitch), and so on has been carried out for about five years by onboard monitoring system installed ocean-going vessel. Measured wave data, including wave height, wave period and wave direction, are thoroughly evaluated with corresponding onboard weather observation data by comparing directly in terms of time series and statistical values. Then, short term prediction of ship motions (roll and pitch) based on the measured wave data are compared with onboard motion data measured by vertical gyro. From the results described, good accuracy and effectiveness of wave measurements by an onboard radar wave meter for safe navigation are demonstrated.

HF radar measurements of ocean wave parameters during NURWEC

1986 ◽  
Vol 11 (2) ◽  
pp. 219-234 ◽  
Author(s):  
L. Wyatt ◽  
J. Venn ◽  
G. Burrows ◽  
A. Ponsford ◽  
M. Moorhead ◽  
...  
Keyword(s):  
Hf Radar ◽  
Ocean Wave ◽  
Wave Parameters ◽  
Radar Measurements

scholarly journals Nearshore Waves and Littoral Drift Along a Micro-Tidal Wave-Dominated Coast Having Comparable Wind-Sea and Swell Energy

2020 ◽  
Vol 8 (1) ◽  
pp. 55
Author(s):  
Jesbin George ◽  
V. Sanil Kumar ◽  
R. Gowthaman ◽  
Jai Singh
Keyword(s):  
Sediment Transport ◽  
Wave Model ◽  
Model Data ◽  
Wave Direction ◽  
Littoral Drift ◽  
Relative Contribution ◽  
Wave Parameters ◽  
Longshore Sediment Transport ◽  
Wind Sea ◽  
Small Change

The nearshore wave characteristics and variations in littoral drift (longshore sediment transport; LST) are estimated based on different approaches for four years along the Vengurla coast, with comparable wind-sea and swell energy assessed. The waverider buoy-measured data at 15 m water depth is utilized as the input wave parameters along with the reanalysis model data, and the numerical wave model Delft-3D is used for estimating the nearshore wave parameters. The relative contribution of wind-seas and swells on LST rates are specifically examined. The clear prevalence of west-southwest waves implies the prevalence of south to north longshore sediment transport with net transport varying from 0.19–0.37 × 105 m3/yr. LST is strongly dependent on the breaker angle and a small change in the wave direction substantially alters the LST, and hence reanalysis/model data with coarse resolutions produce large errors (~38%) in the LST estimate. The annual gross LST rate based on integral wave parameters is only 58% considering the wind-seas and swells separately, since the wind-sea energy is comparable to swell energy, and the direction of these two systems differs significantly.

Prévision des vagues dans l'estuaire du Saint-Laurent à l'aide d'un modèle bidimensionnel

1999 ◽  
Vol 26 (6) ◽  
pp. 713-723 ◽  
Author(s):  
L Dupuis ◽  
Y Ouellet
Keyword(s):  
Water Waves ◽  
Wave Climate ◽  
Wave Direction ◽  
Limited Region ◽  
Lawrence Estuary ◽  
Wave Data ◽  
Modèle Bidimensionnel ◽  
Wave Heights ◽  
Wave Hindcasting ◽  
2D Model

Until now, wave hindcasting in the Estuary and Gulf of St. Lawrence has been done with one-dimensional models. The objective of the present paper is to verify if the two-dimensional model WAWSP, developed to predict waves on the Great Lakes, could be used in the St. Lawrence estuary, a semi-open fetch limited region. Waves (significant wave heights, peak periods, and directions) hindcast by this 2D model are compared with wave data observed at two buoys in 1991, 1992, and 1993, as well as with the ones obtained with 1D models SPM-77 and SPM-84. As a whole, the 2D model gives better results than 1D models. Wave heights are well reproduced, as long as wind data are well represented. However, wave periods are much smaller than those measured, and wave directions are not accurate, mainly because of the presence of swell in the estuary. This study shows the need to obtain more wave data with better quality in order to validate wave hindcasting models.Key words: water waves, numerical modeling, wave hindcasting, 2D model, wave climate, wave height, wave period, wave direction, calculated versus measured waves.

scholarly journals Heights of SuperDARN F region echoes estimated from the analysis of HF radio wave propagation

2007 ◽  
Vol 25 (9) ◽  
pp. 1987-1994 ◽  
Author(s):  
A. V. Koustov ◽  
D. André ◽  
E. Turunen ◽  
T. Raito ◽  
S. E. Milan
Keyword(s):  
Electron Density ◽  
Hf Radar ◽  
Field Of View ◽  
Data Set ◽  
Density Distributions ◽  
F Region ◽  
The Earth ◽  
Earth Magnetic Field ◽  
Field Lines ◽  
Radar Wave

Abstract. Tomographic estimates of the electron density altitudinal and latitudinal distribution within the Hankasalmi HF radar field of view are used to predict the expected heights of F region coherent echoes by ray tracing and finding ranges of radar wave orthogonality with the Earth magnetic field lines. The predicted ranges of echoes are compared with radar observations concurrent with the tomographic measurements. Only those events are considered for which the electron density distributions were smooth, the band of F region HF echoes existed at ranges 700–1500 km, and there was a reasonable match between the expected and measured slant ranges of echoes. For a data set comprising of 82 events, the typical height of echoes was found to be 275 km.

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