Validation of RADARSAT‐2 fully polarimetric SAR measurements of ocean surface waves

Zhang, Biao; Perrie, Will; He, Yabai

doi:10.1029/2009jc005887

Cited by 39 publications

(35 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a result, only waves with a wavelength longer than 150-200 m in the azimuth are detectable (Hauser et al, 2001). Therefore, only swell wave spectra can be retrieved directly from single-polarization SAR imagery (Lyzenga, 2002;Collard et al, 2005;European Space Agency, 2007) or multi-polarization SAR imagery (He et al, 2006;Zhang et al, 2010). Problems related to 180° wave propagation ambiguity have been resolved by the use of image cross spectra (Vachon and Raney, 1991;Engen and Johnsen, 1995).…”

Section: Introductionmentioning

confidence: 99%

A joint method to retrieve directional ocean wave spectra from SAR and wave spectrometer data

Ren

Yang

Zheng

et al. 2015

Chin. J. Ocean. Limnol.

View full text Add to dashboard Cite

This paper proposes a joint method to simultaneously retrieve wave spectra at diff erent scales from spaceborne Synthetic Aperture Radar (SAR) and wave spectrometer data. The method combines the output from the two diff erent sensors to overcome retrieval limitations that occur in some sea states. The wave spectrometer sensitivity coeffi cient is estimated using an eff ective signifi cant wave height (SWH), which is an average of SAR-derived and wave spectrometer-derived SWH. This averaging extends the area of the sea surface sampled by the nadir beam of the wave spectrometer to improve the accuracy of the estimated sensitivity coeffi cient in inhomogeneous sea states. Wave spectra are then retrieved from SAR data using wave spectrometer-derived spectra as fi rst guess spectra to complement the short waves lost in SAR data retrieval. In addition, the problem of 180° ambiguity in retrieved spectra is overcome using SAR imaginary cross spectra. Simulated data were used to validate the joint method. The simulations demonstrated that retrieved wave parameters, including SWH, peak wave length (PWL), and peak wave direction (PWD), agree well with reference parameters. Collocated data from ENVISAT advanced SAR (ASAR), the airborne wave spectrometer STORM, the PHAROS buoy, and the European Centre for Medium-Range Weather Forecasting (ECMWF) were then used to verify the proposed method. Wave parameters retrieved from STORM and two ASAR images were compared to buoy and ECMWF wave data. Most of the retrieved parameters were comparable to reference parameters. The results of this study show that the proposed joint retrieval method could be a valuable complement to traditional methods used to retrieve directional ocean wave spectra, particularly in inhomogeneous sea states.

show abstract

Section: Introductionmentioning

confidence: 99%

A joint method to retrieve directional ocean wave spectra from SAR and wave spectrometer data

Ren

Yang

Zheng

et al. 2015

Chin. J. Ocean. Limnol.

View full text Add to dashboard Cite

show abstract

“…airborne SAR (AIRSAR) or interferometric SAR (InSAR) (Engen et al, 2000;Lee et al, 2000;Schulz-Stellenfleth et al, 2001;Schuler et al, 2004;Lai et al, 2010), ERS 1/2 (Hasselmann et al, 1991(Hasselmann et al, , 1996Voorrips et al, 2001;Lyzenga, 2002;Smith et al, 2003;Violante-Carvalho et al, 2005;Schulz-Stellenfleth et al, 2005Collard et al, 2005;Sun et al, 2009), TerraSAR-X (Lehner et al, 2012) and RADARSAT 1 (He et al, 2004(He et al, , 2006. Recently, additional studies have focused on SAR retrievals of wave spectra from RADARSAT-2, which was launched on December 14, 2007 (Chaturvedi et al, 2013;Zhang et al, 2010).…”

mentioning

confidence: 95%

“…Moreover, these MTFs can also be used to measure wave spectra with full POLSAR data without the need for a complex hydrodynamic MTF (He et al, 2006). This scheme was validated with RADARSAT-2 fine quad polarization C-band SAR data recently (Zhang et al, 2010).…”

mentioning

confidence: 98%

Ocean surface wave measurements from fully polarimetric SAR imagery

Xie

Perrie

et al. 2015

Sci. China Earth Sci.

Self Cite

View full text Add to dashboard Cite

A new method for the retrieval of ocean wave parameters from SAR imagery is developed, based on the shape-from-shading (SFS) technique. Previously, the SFS technique has been used in the reconstruction of 3D landform information from SAR images, in order to generate elevation maps of topography for land surfaces. Here, in order to retrieve ocean wave characteristics, we apply the SFS methodology, together with a method to orient the angular measurements of the azimuth slope and range slope, in the measurement of ocean surface waves. This method is applied to high resolution fine-quad polarization mode (HH, VV, VH and HV) C-band RADARSAT-2 SAR imagery, in order to retrieve ocean wave spectra and extract wave parameters. Collocated in situ buoy measurements are used to validate the reliability of this method. Results show that the method can reliably estimate wave height, dominant wave period, dominant wave length and dominant wave direction from C-band SAR images. The advantage of this method is that it does not depend on modulation transfer functions (MTFs), in order to measure ocean surface waves. This method can be used in monitoring ocean surface wave propagation through open water areas into ice-covered areas, especially the marginal ice zone (MIZ) in polar oceans.polarimetric SAR imagery, ocean surface wave, shape from shading Citation:Xie T, Perrie W, He Y J, et al. 2015. Ocean surface wave measurements from fully polarimetric SAR imagery. Science China: Earth Sciences,

show abstract

“…Polarimetric SAR wave retrieval algorithms yield reasonable results against buoy measurements [22], and currently the only free and open SAR data source is from the available two-channel C-band Sentinel-1 SAR, either in VV-and VH-polarization or in HH-and HV-polarization.…”

Section: Introductionmentioning

confidence: 99%

Ocean Wave Parameters Retrieval from Sentinel-1 SAR Imagery

Shao

Zhang

et al. 2016

Remote Sensing

View full text Add to dashboard Cite

Abstract:In this paper, a semi-empirical algorithm for significant wave height (H s ) and mean wave period (T mw ) retrieval from C-band VV-polarization Sentinel-1 synthetic aperture radar (SAR) imagery is presented. We develop a semi-empirical function for H s retrieval, which describes the relation between H s and cutoff wavelength, radar incidence angle, and wave propagation direction relative to radar look direction. Additionally, T mw can be also calculated through H s and cutoff wavelength by using another empirical function. We collected 106 C-band stripmap mode Sentinel-1 SAR images in VV-polarization and wave measurements from in situ buoys. There are a total of 150 matchup points. We used 93 matchups to tune the coefficients of the semi-empirical algorithm and the rest 57 matchups for validation. The comparison shows a 0.69 m root mean square error (RMSE) of H s with a 18.6% of scatter index (SI) and 1.98 s RMSE of T mw with a 24.8% of SI. Results indicate that the algorithm is suitable for wave parameters retrieval from Sentinel-1 SAR data.

show abstract

Validation of RADARSAT‐2 fully polarimetric SAR measurements of ocean surface waves

Cited by 39 publications

References 22 publications

A joint method to retrieve directional ocean wave spectra from SAR and wave spectrometer data

A joint method to retrieve directional ocean wave spectra from SAR and wave spectrometer data

Ocean surface wave measurements from fully polarimetric SAR imagery

Ocean Wave Parameters Retrieval from Sentinel-1 SAR Imagery

Contact Info

Product

Resources

About