Ocean Dynamics

, Volume 66, Issue 4, pp 527–538 | Cite as

Inversion and assessment of swell waveheights from HF radar spectra in the Iroise Sea

  • Weili Wang
  • Philippe Forget
  • Changlong Guan


As an extension of previous work in Wang et al. (Ocean Dyn 64:1447–1456, 2014), this article presents significant waveheights of swell inverted from a 13 month dataset of two high-frequency (HF) phased array radars. As an important intermediate variable in the calculation of significant waveheights, relative swell directions obtained by two different methods from a single radar station are also presented. The impact of the inaccuracy of relative swell direction on the calculation of waveheight is investigated and an alternative way of using constant swell direction is proposed. Radar-inverted swell significant waveheights using different ranges of relative swell directions are investigated. Results are assessed by WAVEWATCH III model hind casts. Analysis of the complete database shows that radar-inverted swell significant waveheights agree reasonably well with model estimates with large scatter. Standard deviation of the difference between the two estimations increases with waveheight, whereas the relative standard deviation, normalized by waveheight, keeps nearly constant. The constant direction scheme of waveheight inversion gives good estimations except for energetic swell exceeding the small perturbation assumption. Statistical analysis suggests that radar measurement uncertainty explains a considerable part of the difference between radar and model estimates. Swell estimates from both radar stations are consistent. This enables combined use of both radar spectra at common radar cells. Use of double spectra solves the ambiguity of relative swell direction, i.e., absolute swell direction is obtained, and effectively improves the accuracy of swell direction by the least-squares method.


Swell Significant waveheight HF radar WAVEWATCH III wave model Iroise Sea 



Radar data were kindly provided by SHOM (Service Hydrographique et Océanographique de la Marine) thanks to the projects Previmer and EPIGRAM (funded under contract ANR-08-BLAN-0330). WAVEWATCH III wave model data was provided by the IOWAGA project funded by the ERC under grant number 240009. This study is supported by Minisitry of Science and Technology of China (No.2011BAC03B01), National Natural Science Foundation of China (No.41376010).


  1. Ardhuin F, Chapron B, Collard F (2009) Observation of swell dissipation across oceans. Geophys Res Lett 36:L06607. doi: 10.1029/2008GL037030 CrossRefGoogle Scholar
  2. Ardhuin F, Rogers E, Babanin AV et al (2010) Semi-empirical dissipation source functions for wind-wave models: part I, definition, calibration and validation. J Phys Oceanogr 40:1917–1941. doi: 10.1175/2010JPO4324.1 CrossRefGoogle Scholar
  3. Barrick DE (1972a) First-order theory and analysis of MF/HF/VHF scatter from the sea. IEEE Trans Antennas Propag 20:2–10CrossRefGoogle Scholar
  4. Barrick DE (1972b) Remote sensing of sea state by radar. In: Derr VE (ed) Remote sensing of the troposphere. US Government Printing Office, WashingtonGoogle Scholar
  5. Barrick DE (1977) Extraction of wave parameters from measured HF radar sea-echo Doppler spectra. Radio Sci 12(3):415–424CrossRefGoogle Scholar
  6. Barrick DE (1980) Accuracy of parameter extraction from sample-averaged sea-echo Doppler spectra. IEEE Trans Antennas Propag 28:1–11CrossRefGoogle Scholar
  7. Broche P (1979) Estimation du spectre directionnel des vagues par radar decametrique coherent. AGARD Conference on special topics in HF propagation, Proc. Lisbon, 28 May-1 June, 1979. AGARD-CP-263Google Scholar
  8. Collard F, Ardhuin F, Chapron B (2009) Monitoring and analysis of ocean swell fields from space: new methods for routine observations. J Geophys Res 114:C07023. doi: 10.1029/2008JC005215 CrossRefGoogle Scholar
  9. Darbyshire J (1952) The generation of waves by wind. Proc R Soc London, Ser A 215(1122):299–328CrossRefGoogle Scholar
  10. Forget P, Broche P, de Maistre JC, Fontanel A (1981) Sea state frequency features observed by ground wave HF Doppler radar. Radio Sci 16(5):917–925. doi: 10.1029/RS016i005p00917 CrossRefGoogle Scholar
  11. Forget P, Broche P, Cuq F (1995) Principles of swell measurement by SAR with application to ERS-1 observations off the Mauritanian coast. Int J Remote Sens 16:2403–2422CrossRefGoogle Scholar
  12. Grosdidier S, Forget P, Barbin Y, Guerin CA (2014) HF bistatic ocean Doppler spectra: simulation versus experimentation. IEEE Trans Geosci Remote Sens 52(4):2138–2148. doi: 10.1109/TGRS.2013.2258352 CrossRefGoogle Scholar
  13. Gurgel KW, Antonischki G, Essen HH, Schlick T (1999) Wellen radar (WERA): a new ground-wave based HF radar for ocean remote sensing. Coast Eng 37:219–234CrossRefGoogle Scholar
  14. Hasselmann K (1971) Determination of ocean-wave spectra from Doppler radio return from the sea surface. Nat Phys Sci 229:16–17. doi: 10.1038/physci229016a0 CrossRefGoogle Scholar
  15. Hisaki Y (2006) Ocean wave directional spectra estimation from an HF ocean radar with a single antenna array: methodology. J Atmos Ocean Technol 23:268–286CrossRefGoogle Scholar
  16. Holt B, Liu AK, Wang DW, Gnanadesikan A, Chen HS (1998) Tracking storm-generated waves in the northeast Pacific Ocean with ERS-1 synthetic aperture radar imagery and buoys. J Geophys Res 103(C4):7917–7929CrossRefGoogle Scholar
  17. Ivonin DV, Shrira VI, Broche P (2006) On the singular nature of the second-order peaks in HF radar sea echo. IEEE J Ocean Eng 31(4):751–767CrossRefGoogle Scholar
  18. Jiang H, Chen G (2013) A global view on the swell and wind sea climate by the Jason-1 mission: a revisit. J Atmos Ocean Technol 30:1833–1841. doi: 10.1175/JTECH-12-00180.1 CrossRefGoogle Scholar
  19. Kudryavtsev VN, Makin VK (2004) Impact of swell on the marine atmospheric boundary layer. J Phys Oceanogr 34:934–949CrossRefGoogle Scholar
  20. Lipa BJ, Barrick DE (1980) Methods for the extraction of long-period ocean wave parameters from narrow beam HF radar sea echo. Radio Sci 15(4):843–853CrossRefGoogle Scholar
  21. Lipa BJ, Barrick DE (1986) Extraction of sea state from HF radar sea echo: mathematical theory and modeling. Radio Sci 21(1):81–100. doi: 10.1029/RS021i001p00081 CrossRefGoogle Scholar
  22. Lipa B, Nyden B (2005) Directional wave information from the SeaSonde. IEEE J Ocean Eng 30:221–231. doi: 10.1109/JOE.2004.839929 CrossRefGoogle Scholar
  23. Lipa BJ, Barrick DE, Maresca JW Jr (1981) HF radar measurements of long ocean waves. J Geophys Res 86(C5):4089–4102. doi: 10.1029/JC086iC05p04089 CrossRefGoogle Scholar
  24. Munk WH, Miller GR, Snodgrass FE, Barber NF (1963) Directional recording of swell from distant storms. Phil Trans R Soc London A255:505–584CrossRefGoogle Scholar
  25. Portilla J, Ocampo-Torres FJ, Monbaliu J (2009) Spectral partitioning and identification of wind sea and swell. J Atmos Ocean Technol 26:107–122. doi: 10.1175/2008JTECHO609.1 CrossRefGoogle Scholar
  26. Roland A, Ardhuin F (2014) On the developments of spectral wave models: numeric and parameterizations for the coastal ocean. Ocean Dyn 64(6):833–846. doi: 10.1007/s10236-014-0711-z CrossRefGoogle Scholar
  27. Smedman A, Högström U, Sahleé E, Drennan WM, Kahma KK, Pettersson H, Zhang F (2009) Observational study of marine atmospheric boundary layer characteristics during swell. J Atmos Sci 66:2747–2763. doi: 10.1175/2009JAS2952.1 CrossRefGoogle Scholar
  28. Snodgrass FE, Groves GW, Hasslemann KF, Miller GR, Munk WH, Powers WH (1966) Propagation of ocean swell across the Pacific. Phil Trans R Soc London A259:430–497Google Scholar
  29. Tolman HL (2008) A mosaic approach to wind wave modeling. Ocean Model 25:35–47. doi: 10.1016/j.ocemod.2008.06.005 CrossRefGoogle Scholar
  30. Wang W, Forget P, Guan C (2014) Inversion of swell frequency from a 1-year HF radar dataset collected in Brittany (France). Ocean Dyn 64(10):1447–1456. doi: 10.1007/s10236-014-0759-9 CrossRefGoogle Scholar
  31. Wyatt LR (1990) A relaxation method for integral inversion applied to HF radar measurement of the ocean wave directional spectrum. Int J Remote Sens 11:1481–1494CrossRefGoogle Scholar
  32. Wyatt LR, Green JJ, Middleditch A (2011) HF radar data quality requirements for wave measurement. Coast Eng 58:327–336CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  • Weili Wang
    • 1
    • 2
    • 3
    • 4
  • Philippe Forget
    • 3
    • 4
  • Changlong Guan
    • 1
  1. 1.Physical Oceanography LaboratoryOcean University of ChinaQingdaoChina
  2. 2.Shandong Provincial Key Laboratory of Marine Ecology and Environment & Disaster Prevention and MitigationNorth China Sea Marine Forecasting Center of State Oceanic AdministrationQingdaoChina
  3. 3.CNRS/INSU, IRD, Mediterranean Institute of Oceanography (MIO), UM 110Université de ToulonLa GardeFrance
  4. 4.CNRS/INSU, IRD, MIO, UM 110Aix-Marseille UniversitéMarseilleFrance

Personalised recommendations