Global SAR Spectral Analysis of Intermediate Ocean Waves: Statistics and Derived Real Aperture Radar Modulation
Abstract
:1. Introduction
2. Dataset and MACS
2.1. Sentinel-1 Wave Mode
2.2. Definition of MACS
3. Statistics of MMACS(0)
Speckle Noise
3.1. Statistics of Noise-Free MMACS(0)
3.1.1. Azimuthal Modulation
3.1.2. Upwind-to-Downwind and -Crosswind Asymmetry
4. RAR Modulation Derived from MMACS(0)
4.1. Simulation of SAR Image Cross-Spectra
4.2. Derived RAR Modulation
5. Conclusions
Author Contributions
Funding
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
- Elfouhaily, T.; Chapron, B.; Katsaros, K.; Vandemark, D. A unified directional spectrum for long and short wind-driven waves. J. Geophys. Res. Oceans 1997, 102, 15781–15796. [Google Scholar] [CrossRef]
- Ryabkova, M.; Karaev, V.; Guo, J.; Titchenko, Y. A Review of Wave Spectrum Models as Applied to the Problem of Radar Probing of the Sea Surface. J. Geophys. Res. Oceans 2019, 124, 7104–7134. [Google Scholar] [CrossRef]
- Jackson, C.R.; Apel, J.R. (Eds.) Synthetic Aperture Radar Marine User’s Manual; U.S. Department of Commerce National Oceanic and Atmospheric Administration, National Environmental Satellite, Data, and Information, Service Office of Research and Applications: Washington, DC, USA, 2004. [Google Scholar]
- Hasselmann, K.; Hasselmann, S. On the nonlinear mapping of an ocean wave spectrum into a synthetic aperture radar image spectrum and its inversion. J. Geophys. Res. 1991, 96, 10713–10729. [Google Scholar] [CrossRef]
- Kudryavtsev, V.; Kozlov, I.; Chapron, B.; Johannessen, J.A. Quad-polarization SAR features of ocean currents. J. Geophys. Res. Oceans 2014, 119, 6046–6065. [Google Scholar] [CrossRef]
- Alpers, W.; Hennings, I. A theory of the imaging mechanism of underwater bottom topography by real and synthetic aperture radar. J. Geophys. Res. 1984, 89, 10529–10546. [Google Scholar] [CrossRef]
- Ardhuin, F.; Collard, F.; Chapron, B.; Girard-Ardhuin, F.; Guitton, G.; Mouche, A.; Stopa, J.E. Estimates of ocean wave heights and attenuation in sea ice using the SAR wave mode on Sentinel-1A. Geophys. Res. Lett. 2015, 42, 2317–2325. [Google Scholar] [CrossRef]
- Ardhuin, F.; Stopa, J.; Chapron, B.; Collard, F.; Smith, M.; Thomson, J.; Doble, M.; Blomquist, B.; Persson, O.; Collins, C.O.; et al. Measuring ocean waves in sea ice using SAR imagery: A quasi-deterministic approach evaluated with Sentinel-1 and in situ data. Remote Sens. Environ. 2017, 189, 211–222. [Google Scholar] [CrossRef]
- Huang, B.; Li, X. Study on Retrievals of Ocean Wave Spectrum by Spaceborne SAR in Ice-Covered Areas. Remote Sens. 2022, 14, 6086. [Google Scholar] [CrossRef]
- Pramudya, F.S.; Pan, J.; Devlin, A.T.; Lin, H. Enhanced Estimation of Significant Wave Height with Dual-Polarization Sentinel-1 SAR Imagery. Remote Sens. 2021, 13, 124. [Google Scholar] [CrossRef]
- Wang, H.; Mouche, A.; Husson, R.; Grouazel, A.; Chapron, B.; Yang, J. Assessment of Ocean Swell Height Observations from Sentinel-1A/B Wave Mode against Buoy In Situ and Modeling Hindcasts. Remote Sens. 2022, 14, 862. [Google Scholar] [CrossRef]
- Vachon, P.W.; Krogstad, H.E.; Paterson, J.S. Airborne and spaceborne synthetic aperture radar observations of ocean waves. Atmos.-Ocean 1994, 32, 83–112. [Google Scholar] [CrossRef]
- Engen, G.; Vachon, P.W.; Johnsen, H.; Dobson, F.W. Retrieval of ocean wave spectra and RAR MTF’s from dual-polarization SAR data. IEEE Trans. Geosci. Remote Sens. 2000, 38, 391–403. [Google Scholar] [CrossRef]
- Collard, F.; Ardhuin, F.; Chapron, B. Monitoring and analysis of ocean swell fields from space: New methods for routine observations. J. Geophys. Res. Oceans 2009, 114, C07023. [Google Scholar] [CrossRef]
- Zhang, B.; Perrie, W.; He, Y. Remote sensing of ocean waves by along-track interferometric synthetic aperture radar. J. Geophys. Res. Oceans 2009, 114, 10015. [Google Scholar] [CrossRef]
- Stopa, J.E.; Ardhuin, F.; Husson, R.; Jiang, H.; Chapron, B.; Collard, F. Swell dissipation from 10 years of Envisat advanced synthetic aperture radar in wave mode. Geophys. Res. Lett. 2016, 43, 3423–3430. [Google Scholar] [CrossRef]
- Engen, G.; Johnsen, H. SAR-ocean wave inversion using image cross spectra. IEEE Trans. Geosci. Remote Sens. 1995, 33, 1047–1056. [Google Scholar] [CrossRef]
- Hasselmann, S.; Brüning, C.; Hasselmann, K.; Heimbach, P. An improved algorithm for the retrieval of ocean wave spectra from synthetic aperture radar image spectra. J. Geophys. Res. Oceans 1996, 101, 16615–16629. [Google Scholar] [CrossRef]
- Jiang, H.; Mouche, A.; Wang, H.; Babanin, A.V.; Chapron, B.; Chen, G. Limitation of SAR Quasi-Linear Inversion Data on Swell Climate: An Example of Global Crossing Swells. Remote Sens. 2017, 9, 107. [Google Scholar] [CrossRef]
- Jacobsen, S.; Høgda, K.A. Estimation of the real aperture radar modulation transfer function directly from synthetic aperture radar ocean wave image spectra without a priori knowledge of the ocean wave height spectrum. J. Geophys. Res. 1994, 99, 14291–14302. [Google Scholar] [CrossRef]
- Phillips, O.M. Spectral and statistical properties of the equilibrium range in wind-generated gravity waves. J. Fluid Mech. 1985, 156, 505–531. [Google Scholar] [CrossRef]
- Li, J.G.; Holt, M. Comparison of Envisat ASAR Ocean Wave Spectra with Buoy and Altimeter Data via a Wave Model. J. Atmos. Ocean. Technol. 2009, 26, 593–614. [Google Scholar] [CrossRef]
- Li, H.; Chapron, B.; Mouche, A.; Stopa, J.E. A New Ocean SAR Cross-Spectral Parameter: Definition and Directional Property Using the Global Sentinel-1 Measurements. J. Geophys. Res. Oceans 2019, 124, 1566–1577. [Google Scholar] [CrossRef]
- Torres, R.; Snoeij, P.; Geudtner, D.; Bibby, D.; Davidson, M.; Attema, E.; Potin, P.; Rommen, B.; Floury, N.; Brown, M.; et al. GMES Sentinel-1 mission. Remote Sens. Environ. 2012, 120, 9–24. [Google Scholar] [CrossRef]
- Sentinel-1 Mission Performance Center. Sentinel-1 Product Specification; Technical Report S1-RS-MDA-52-7441; ESA Unclassified—For Official Use; European Space Agency: Paris, France, 2020. [Google Scholar]
- Johnsen, H.; Collard, F. Sentinel-1 Ocean Swell Wave Spectra (OSW) Algorithm Definition; Technical Report; Norut: Tromsø, Norway, 2009. [Google Scholar]
- Hasselmann, K.; Raney, R.K.; Plant, W.J.; Alpers, W.; Shuchman, R.A.; Lyzenga, D.R.; Rufenach, C.L.; Tucker, M.J. Theory of synthetic aperture radar ocean imaging: A MARSEN view. J. Geophys. Res. 1985, 90, 4659–4686. [Google Scholar] [CrossRef]
- Schulz-Stellenfleth, J.; Lehner, S. A noise model for estimated synthetic aperture radar look cross spectra acquired over the ocean. IEEE Trans. Geosci. Remote Sens. 2005, 43, 1443–1452. [Google Scholar] [CrossRef]
- Hersbach, H.; Stoffelen, A.; de Haan, S. An improved C-band scatterometer ocean geophysical model function: CMOD5. J. Geophys. Res. Oceans 2007, 112, 03006. [Google Scholar] [CrossRef]
- Stoffelen, A.; Verspeek, J.A.; Vogelzang, J.; Verhoef, A. The CMOD7 Geophysical Model Function for ASCAT and ERS Wind Retrievals. IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens. 2017, 10, 2123–2134. [Google Scholar] [CrossRef]
- Zhang, B.; Perrie, W.; He, Y. Wind speed retrieval from RADARSAT-2 quad-polarization images using a new polarization ratio model. J. Geophys. Res. Oceans 2011, 116, 08008. [Google Scholar] [CrossRef]
- Mouche, A.; Chapron, B. Global C-Band Envisat, RADARSAT-2 and Sentinel-1 SAR measurements in copolarization and cross-polarization. J. Geophys. Res. Oceans 2015, 120, 7195–7207. [Google Scholar] [CrossRef]
- Alpers, W.R.; Ross, D.B.; Rufenach, C.L. On the detectability of ocean surface waves by real and synthetic aperture radar. J. Geophys. Res. Oceans 1981, 86, 6481–6498. [Google Scholar] [CrossRef]
- Ardhuin, F.; Rogers, E.; Babanin, A.V.; Filipot, J.F.; Magne, R.; Roland, A.; van der Westhuysen, A.; Queffeulou, P.; Lefevre, J.M.; Aouf, L.; et al. Semiempirical Dissipation Source Functions for Ocean Waves. Part I: Definition, Calibration, and Validation. J. Phys. Oceanogr. 2010, 40, 1917–1941. [Google Scholar] [CrossRef]
- Valenzuela, G.R. Theories for the interaction of electromagnetic and oceanic waves—A review. Bound.-Layer Meteorol. 1978, 13, 61–85. [Google Scholar] [CrossRef]
- Kerbaol, V.; Chapron, B.; Vachon, P.W. Analysis of ERS-1/2 synthetic aperture radar wave mode imagettes. J. Geophys. Res. Oceans 1998, 103, 7833–7846. [Google Scholar] [CrossRef]
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Li, K.; Li, H. Global SAR Spectral Analysis of Intermediate Ocean Waves: Statistics and Derived Real Aperture Radar Modulation. Remote Sens. 2025, 17, 1416. https://doi.org/10.3390/rs17081416
Li K, Li H. Global SAR Spectral Analysis of Intermediate Ocean Waves: Statistics and Derived Real Aperture Radar Modulation. Remote Sensing. 2025; 17(8):1416. https://doi.org/10.3390/rs17081416
Chicago/Turabian StyleLi, Kehan, and Huimin Li. 2025. "Global SAR Spectral Analysis of Intermediate Ocean Waves: Statistics and Derived Real Aperture Radar Modulation" Remote Sensing 17, no. 8: 1416. https://doi.org/10.3390/rs17081416
APA StyleLi, K., & Li, H. (2025). Global SAR Spectral Analysis of Intermediate Ocean Waves: Statistics and Derived Real Aperture Radar Modulation. Remote Sensing, 17(8), 1416. https://doi.org/10.3390/rs17081416