Wind and wave measurements using complex ERS-2 SAR wave mode data

Lehner, Susanne; Schulz‐Stellenfleth, Johannes; Schättler, Birgit; Breit, Helko; Horstmann, Jochen

doi:10.1109/36.868882

Cited by 111 publications

(58 citation statements)

References 21 publications

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“…To exclude SAR images that contain features not associated with the local wind, a filter is applied. The filter was developed to distinguish between homogeneous and inhomogeneous SAR images and, furthermore, to retrieve ocean wave spectra and wind speed fields [22], [23]. This technique uses tests involving the statistical properties of periodograms, as commonly used for spectral estimations.…”

Section: A Data Setmentioning

confidence: 99%

Ocean Vector Winds Retrieval From C-Band Fully Polarimetric SAR Measurements

Zhang

Perrie

Vachon

et al. 2012

IEEE Trans. Geosci. Remote Sensing

119

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Abstract-We present an efficient algorithm for retrieving the ocean-surface wind vector from C-band Radar Satellite RADARSAT-2 fully polarimetric synthetic aperture radar (SAR) measurements based upon the copolarized geophysical model function, i.e., CMOD5.N, and the cross-polarized ocean backscatter model, i.e., C-2PO. The analysis of fine quad-polarization mode single-look complex SAR data and collocated in situ moored buoy observations reveals that the polarimetric correlation coefficient between co-and cross-polarization channels has odd symmetry with respect to the wind direction. This characteristic is different from the feature that normalized radar cross sections for quadpolarization have even symmetry regarding the wind direction. We first use the C-2PO model to directly retrieve wind speeds without any external wind-direction and radar-incidence-angle inputs. Subsequently, the retrieved wind speeds, along with incidence angles and CMOD5.N, are employed to invert the wind direction, still with ambiguities. The odd-symmetry property is then applied to remove the wind direction ambiguities. Thus, it is shown that fully polarimetric SAR measurements provide complementary directional information for the ocean-surface wind fields. This method has the potential to improve wind vector retrievals from space.Index Terms-Fully polarimetric SAR, ocean-surface wind fields, polarimetric correlation coefficient, SAR polarimetric oddsymmetry, simultaneous wind speed and direction SAR retrievals.

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Section: A Data Setmentioning

confidence: 99%

Ocean Vector Winds Retrieval From C-Band Fully Polarimetric SAR Measurements

Zhang

Perrie

Vachon

et al. 2012

IEEE Trans. Geosci. Remote Sensing

119

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“…For this reason, in this paper we use wind and pressure fields based on the HydrometRankin Vortex analytical model presented by Holland (1980Holland ( , 2008 and Bretschneider (1990). This model has already been implemented and validated using data from buoys and satellite-borne synthetic aperture radar during several hurricane historical events, such as in Lehner et al (2000), Silva et al (2002), Powell et al (2010), or Diaz-Hernandez et al (2012. Figure 3 shows the measured wind speed and pressure time series data (Haeseler 2012) at meteorological stations Ponta Delgada and Santa Maria, located in the Azores Islands, and its comparison with results obtained from the parametric model during Hurricane Gordon.…”

Section: Hurricane High-resolution Wind Datamentioning

confidence: 99%

Numerical Analysis and Diagnosis of the Hydrodynamic Effects Produced by Hurricane Gordon along the Coast of Spain

Diaz-Hernandez

Méndez

Mı́nguez

2014

Weather and Forecasting

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This paper presents a detailed hindcast for the generation and propagation of sea state variables-significant wave height H s , peak period T p , mean direction u, and spectral shape g -s -associated with cyclonic events to numerically diagnose their possible hydrodynamic effects over the northeastern Atlantic. An example of such cyclonic events is Hurricane Gordon, which occurred during the second half of August 2012. Extreme hurricane-strength winds produced new and atypically low-frequency (about 14 s) packs of energy. The preexistent wave spectrum suddenly experienced an addition of low-frequency energy along the coast of C adiz, Spain. This study presents the results of a comprehensive analysis developed to reconstruct the events produced by Hurricane Gordon (2012) along the coast of C adiz. The analysis features the use of (i) parametric models for the characterization of hurricane winds and pressure fields, (ii) implementation of the Simulating Waves Nearshore (SWAN) model for the generation and propagation of waves in the northeast Atlantic Ocean, and (iii) its coupling with the MOPLA-taken from the Spanish acronym for wave propagation model, current, and morphodynamic evolution of beaches-model for the evaluation of longshore currents. The numerical wave characterization, generation, and propagation were validated with instrumental data from deep-water and coastal buoys.

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“…The C-band radar operates with vertical polarization in transmit and receives and provides a spatial resolution of about 10 m in azimuth direction and 20 m in range direction. The required SAR wave mode single look complex (SLC) imagettes, which are not available as standard products, were reprocessed at German Aerospace Center (DLR) (Lehner et al 2000) from raw data provided by the European Space Agency (ESA). 1535 test imagettes classified by eye including four types of imagettes i. e. water, slick, ice and undefined inhomogeneous imagettes were applied to develop new classification parameters and are shown in Fig.…”

Section: Wave Mode Ers-2 Imagettementioning

confidence: 99%

A New Algorithm to Classify the Homogeneity of ERS-2 Wave Mode SAR Imagette

Song

Panda

Zhang

et al. 2013

J Indian Soc Remote Sens

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A new classification parameter is developed using 1535 ERS-2 wave mode synthetic aperture radar (SAR) test imagettes to better differentiate homogeneous and inhomogeneous imagettes. The comparison between the new parameter (Min) and the previous one (Inhomo) (Schulz-Stellenfleth and Lehner, 2004) was done under varied threshold values of Inhomo. It is concluded that the performance of 'Min' is much better than 'Inhomo' when applying to the 1535 test imagettes. Furthermore, both Min and Inhomo are applied to nearly 1 million imagettes collected for the period from 1 September 1998 to 30 November 2000. The comparisons of the global inhomogeneous distribution between 'Min' and 'Inhomo' reveal that both the areas and percentage of inhomogeneity calculated by 'Min' are larger than that calculated by 'Inhomo'. By analyzing the low wind speed distribution of HOAPS data, we found that low wind speed over the ocean is one of the key reasons for the inhomogeneity of SAR imagettes.

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Wind and wave measurements using complex ERS-2 SAR wave mode data

Cited by 111 publications

References 21 publications

Ocean Vector Winds Retrieval From C-Band Fully Polarimetric SAR Measurements

Ocean Vector Winds Retrieval From C-Band Fully Polarimetric SAR Measurements

Numerical Analysis and Diagnosis of the Hydrodynamic Effects Produced by Hurricane Gordon along the Coast of Spain

A New Algorithm to Classify the Homogeneity of ERS-2 Wave Mode SAR Imagette

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