<i>S</i> band Doppler radar measurements of bathymetry, wave energy fluxes, and dissipation across an offshore bar

McGregor, John; Poulter, E. M.; Smith, M. J.

doi:10.1029/98jc00447

Cited by 26 publications

(19 citation statements)

References 18 publications

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“…In a second group of methods, characteristics of the sea surface are used to estimate depth. An often applied method within this group is based on the analysis of a sequence of (instantaneous) images or cross-shore pixel arrays acquired with, for instance, shore-based [7] or airborne [8], [9] optical systems, or X-band [10] or S-band [11] radar. Gradients in the phase difference between (processed) intensities at two closely spaced pixels provide an estimate of the local wavenumber, which then is inverted to depth using linear wave theory's dispersion relationship.…”

Section: Video Observations and Model Predictions Ofmentioning

confidence: 99%

Video observations and model predictions of depth-induced wave dissipation

Aarninkhof¹,

Ruessink

2004

IEEE Trans. Geosci. Remote Sensing

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Abstract-Time-averaged video observations of the nearshore zone show the process of wave breaking as one or more white alongshore bands of high intensity, corresponding to the preferential location of breaking-wave dissipation on one or more sandbars. Across a known depth profile, similar bands of dissipation can be predicted with existing wave transformation models based on the wave energy balance. This opens up possibilities for estimating bathymetry from video observations by processing observed intensities into a model-predicted proxy of wave dissipation and the inverse modeling of this dissipation proxy into depth. The objectives of this paper are: 1) to present a technique for processing time-averaged cross-shore image intensity profiles into profiles that solely contain the contribution due to wave breaking and 2) to empirically determine which modeled wave dissipation proxy relates best to the cross-shore shape of the obtained breaking-induced intensity. The processing technique involves the removal of background illumination and noise, and, most importantly, a correction for white foam that after being generated in the breaking process remains floating at the water surface. This foam thus contributes to high image intensities but is not predicted by wave transformation models. Based on video and bathymetric data collected at the double-barred beach at Egmond aan Zee, The Netherlands and a standard wave transformation model containing the wave and roller energy balances, we find that the modeled cross-shore distribution of the dissipation of the energy of the surface roller (the white aerated mass of water at the breaking-wave front) matches the observed cross-shore shape of breaking-induced intensity well. Other hypothesized dissipation proxies result in a larger ( 10 m) seaward bias in the locations of maximum breaking-induced intensity and model-predicted dissipation or do not predict the cross-shore change in the area below the breaking-induced intensity bands correctly.

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Section: Video Observations and Model Predictions Ofmentioning

confidence: 99%

Video observations and model predictions of depth-induced wave dissipation

Aarninkhof¹,

Ruessink

2004

IEEE Trans. Geosci. Remote Sensing

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“…In this context, remote sensing methods have been developed, based on different platforms and sensors, e.g. airplanes [1], satellites [2], even groundbased sensors, cameras [3][4] and radars [5][6][7]. The X-band radar systems have an important role in this field due to their flexibility, durability, easy and continuous operation independently from external conditions and relatively low cost; there are several algorithms for the estimation of sea state parameters, e.g.…”

Section: Introductionmentioning

confidence: 99%

Analysis of nautical X-band radar images for the generation of bathymetric map by the NSP method

Serafino

Ludeno

Flampouris

et al. 2012

2012 IEEE International Geoscience and Remote Sensing Symposium

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This work presents the experimental validation of a novel data processing approach to estimate the local depth in a shallow coastal area starting from X-band radar data. The approach is based on the maximization of the Normalized Scalar Product (NSP) between the measured and the theoretical wave dispersion relations, which embed the dependence on the searched for parameters (current vector and depth). The use of NSP approach allows obtaining a high resolution spatial map of the investigated area and a thorough statistical analysis of this approach is carried out by comparison with the ground truth data collected by a multibeam echo-sounder. Finally, the accuracy of the NSP approach is compared with the one achieved by other methods and prove to provide better results.Index Terms-sea state monitoring, X-band radar data, shallow coastal areas, bathymetry

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“…The study of the coherent method began in the 1980s when Plant and Schuler proposed a preliminary theory and approach for deducing wave height spectra from the velocity of water particles [14,15]. In the 1990s, various experiments using microwave Doppler radar were conducted [5,[16][17][18][19]; however, none of the experimental results fully obtained the directional wave height spectra. Recently, the coherent method has been applied on the X-band radar, and the results are very good [20].…”

Section: Introductionmentioning

confidence: 99%

S-Band Doppler Wave Radar System

et al. 2017

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Abstract:In this paper, a novel shore-based S-band microwave Doppler coherent wave radar (Microwave Ocean Remote SEnsor (MORSE)) is designed to improve wave measurements. Marine radars, which operate in the X band, have been widely used for ocean monitoring because of their low cost, small size and flexibility. However, because of the non-coherent measurements and strong absorption of X-band radio waves by rain, these radar systems suffer considerable performance loss in moist weather. Furthermore, frequent calibrations to modify the modulation transfer function are required. To overcome these shortcomings, MORSE, which operates in the S band, was developed by Wuhan University. Because of the coherent measurements of this sensor, it is able to measure the radial velocity of water particles via the Doppler effect. Then the relation between the velocity spectrum and wave height spectrum can be used to obtain the wave height spectra. Finally, wave parameters are estimated from the wave height spectra by the spectrum moment method. Comparisons between MORSE and Waverider MKIII are conducted in this study, and the results, including the non-directional wave height spectra, significant wave height and average wave period, are calculated and displayed. The correlation coefficient of the significant wave height is larger than 0.9, whereas that of the average wave period is approximately 0.4, demonstrating the effectiveness of MORSE for the continuous monitoring of ocean areas with high accuracy.

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S band Doppler radar measurements of bathymetry, wave energy fluxes, and dissipation across an offshore bar

Cited by 26 publications

References 18 publications

Video observations and model predictions of depth-induced wave dissipation

Video observations and model predictions of depth-induced wave dissipation

Analysis of nautical X-band radar images for the generation of bathymetric map by the NSP method

S-Band Doppler Wave Radar System

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