Skip to main content
Log in

Analysis of factors influencing significant wave height retrieval and performance improvement in spaceborne GNSS-R

  • Original Article
  • Published:
GPS Solutions Aims and scope Submit manuscript

Abstract

As an emerging observational method, spaceborne global navigation satellite system-reflectometry (GNSS-R) has been applied recently for significant wave height (SWH) retrieval. However, the complexity of the sea surface and the influence of multiple potential factors have been constraining the accuracy of SWH retrieval. This study verified the effect of sea surface temperature (SST), sea surface salinity (SSS), and seasonal variation on cyclone-GNSS (CYGNSS) observables for the first time. After controlling for the SWH, the CYGNSS observables exhibit a dependence on SST and SSS, where the dependence on SST dominates. The correlation coefficient (R) between SST and CYGNSS observables is the highest in 3.5–4 m, which is 0.53. In addition, the geographical distribution of retrieval bias exhibits seasonality. Therefore, seasonal factors can provide an additional contribution to SWH retrieval. SWH retrieval is based on the multilayer perceptron. The European center for medium-range weather forecast reanalysis 5th Generation SWH data were used as the reference for the computation of retrieval performance metrics. The results show that after considering SST, salinity, and season, the root mean square error (RMSE) of the retrieved SWH decreases from 0.65 to 0.48 m and the R increases from 0.66 to 0.83. The retrievals were compared to the ground truth measurements from the National Data Buoy Center buoys; the RMSE decreased from 0.52–1.07 m to 0.30–0.61 m, and the R increased from 0.44–0.71 to 0.60–0.78.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14
Fig. 15
Fig. 16
Fig. 17
Fig. 18
Fig. 19
Fig. 20

Similar content being viewed by others

Availability of data and materials

The CYGNSS data presented in this study are openly available in PODAA at https://podaac.jpl.nasa.gov/dataset/CYGNSS_L1_V3.1. The SWH data are openly available in ECMWF at https://cds.climate.copernicus.eu/cdsapp#!/dataset/reanalysisera5-single-levels. The SSS data are openly available in the Multi-Mission Optimally Interpolated SSS Global Dataset V1 at https://search.earthdata.nasa.gov/.

References

  • Alonso-Arroyo A, Camps A, Park H, Pascual D, Onrubia R, Martin F (2014) Retrieval of significant wave height and mean sea surface level using the GNSS-R interference pattern technique: results from a three-month field campaign. IEEE Trans Geosci Remote Sens 53:3198–3209

    Article  Google Scholar 

  • Alpers W, Hasselmann K (1982) Spectral signal to clutter and thermal noise properties of ocean wave imaging synthetic aperture radars. Int J Remote Sens 3:423–446

    Article  Google Scholar 

  • Asgarimehr M, Hoseini M, Semmling M, Ramatschi M, Camps A, Nahavandchi H, Wickert J (2021) Remote sensing of precipitation using reflected GNSS signals: response analysis of polarimetric observations. IEEE Trans Geosci Remote Sens 60:1–12

    Article  Google Scholar 

  • Asgarimehr M, Arnold C, Weigel T, Ruf C, Wickert J (2022) GNSS reflectometry global ocean wind speed using deep learning: development and assessment of CYGNSSnet. Remote Sens Environ 269:112801

    Article  Google Scholar 

  • Balasubramaniam R, Ruf CS (2019) The impact of rain on GNSS-R radar scattering cross-section. In: 2019 IEEE international geoscience and remote sensing symposium, Yokohama, Japan, pp 7900–7903

  • Balasubramaniam R, Ruf C (2020) Characterization of rain impact on L-band GNSS-R ocean surface measurements. Remote Sens Environ 239:111607

    Article  Google Scholar 

  • Bu J, Yu K (2022a) A new integrated method of CYGNSS DDMA and LES measurements for significant wave height estimation. IEEE Geosci Remote Sens Lett 19:1–5

    Google Scholar 

  • Bu J, Yu K (2022b) Significant wave height retrieval method based on spaceborne GNSS reflectometry. IEEE Geosci Remote Sens Lett 19:1–5

    Google Scholar 

  • Bu J, Yu K, Ni J, Yan Q, Han S, Wang J, Wang C (2022) Machine learning-based methods for sea surface rainfall detection from CYGNSS delay-doppler maps. GPS Solut 26(4):1–14

    Article  Google Scholar 

  • Bu J, Yu K, Ni J, Huang W (2023a) Combining ERA5 data and CYGNSS observations for the joint retrieval of global significant wave height of ocean swell and wind wave: a deep convolutional neural network approach. J Geodesy 97(8):1–22

    Article  Google Scholar 

  • Bu J, Yu K, Zhu F, Zuo X, Huang W (2023b) Joint retrieval of sea surface rainfall intensity, wind speed, and wave height based on spaceborne GNSS-R: a case study of the oceans near China. Remote Sens 15:2757

    Article  Google Scholar 

  • Camps A, Park H (2022) Sensitivity of delay Doppler map in spaceborne GNSS-R to geophysical variables of the ocean. IEEE J Sel Top Appl Earth Observ Remote Sens 15:8624–8631

    Article  Google Scholar 

  • Clarizia MP, Ruf CS (2016) Wind speed retrieval algorithm for the cyclone global navigation satellite system (CYGNSS) mission. IEEE Trans Geosci Remote Sens 54(8):4419–4432

    Article  Google Scholar 

  • Clarizia MP, Ruf CS, Jales P, Gommenginger C (2014) Spaceborne GNSS-R minimum variance wind speed estimator. IEEE Trans Geosci Remote Sens 52:6829–6843

    Article  Google Scholar 

  • Foti G, Gommenginger C, Srokosz, M (2017) First spaceborne GNSS-Reflectometry observations of hurricanes from the UK Techdemosat-1 mission. Geophys Res Lett 44(12):12358–12366. https://doi.org/10.1002/2017GL076166

    Article  Google Scholar 

  • Garrison JL, Katzberg SJ (2000) The application of reflected GPS signals to ocean remote sensing. Remote Sens Environ 73:175–187

    Article  Google Scholar 

  • Guo W, Du H, Guo C, Southwell BJ, Cheong JW, Dempster AG (2022) Information fusion for GNSS-R wind speed retrieval using statistically modified convolutional neural network. Remote Sens Environ 272:112934

    Article  Google Scholar 

  • Hall C, Cordey R (1988) Multistatic scatterometry. In: Proceedings of the international geoscience and remote sensing symposium, ‘remote sensing: moving toward the 21st century’, Edinburgh, UK, pp 561–562

  • Holthuijsen LH (2010) Waves in oceanic and coastal waters. Cambridge University Press, Cambridge

    Google Scholar 

  • Jin S, Yang S, Yan Q, Jia Y (2022) Significant wave height estimation from CYGNSS delay-doppler map average observations. In: Photonics and electromagnetics research symposium (PIERS), pp 654–659

  • Klein L, Swift C (1977) An improved model for the dielectric constant of sea water at microwave frequencies. IEEE Trans Antennas Propag 25:104–111

    Article  Google Scholar 

  • Li W, Cardellach E, Fabra F, Ribo S, Rius A (2019) Assessment of spaceborne GNSS-R ocean altimetry performance using CYGNSS mission raw data. IEEE Trans Geosci Remote Sens 58:238–250

    Article  Google Scholar 

  • Li B, Yang L, Zhang B, Yang D, Wu D (2020) Modeling and Simulation of GNSS-R Observables With Effects of Swell. IEEE J Sel Top Appl Earth Observ Remote Sens 13:1833–41. https://doi.org/10.1109/jstars.2020.2992037

    Article  Google Scholar 

  • Li Z, Guo F, Chen F, Zhang Z, Zhang X (2023) Wind speed retrieval using GNSS-R technique with geographic partitioning. Satell Navig 4:4

    Article  CAS  Google Scholar 

  • Loria E, O’Brien A, Zavorotny V, Zuffada C (2020) Wind vector and wave height retrieval in inland waters using CYGNSS. In: IGARSS 2020–2020 IEEE international geoscience and remote sensing symposium. IEEE, Waikoloa, HI, USA, pp 7029–7032

  • Marchan-Hernandez JF, Valencia E, Rodriguez-Alvarez N, Ramos-Pérez I, Bosch-Lluis X, Camps A, Eugenio F, Marcello J (2010) Sea-state determination using GNSS-R data. IEEE Geosci Remote Sens Lett 7:621–625

    Article  Google Scholar 

  • Martin-Neira M (1993) A passive reflectometry and interferometry system (PARIS): application to ocean altimetry. ESA Journal 17:331–355

    Google Scholar 

  • Park H, Camps A, Valencia E, Rodriguez-Alvarez N, Bosch-Lluis X, Ramos-Perez I, Carreno-Luengo H (2012) Retracking considerations in spaceborne GNSS-R altimetry. GPS Solut 16(4):507–518

    Article  Google Scholar 

  • Pascual D, Clarizia MP, Ruf CS (2021) Improved CYGNSS wind speed retrieval using significant wave height correction. Remote Sens 13:4313

    Article  Google Scholar 

  • Pan Y, Ren C, Liang Y, Zhang Z, Shi Y (2020) Inversion of surface vegetation water content based on GNSS-IR and MODIS data fusion. Satell Navig 1:21. https://doi.org/10.1186/s43020-020-00021-z

    Article  Google Scholar 

  • Peng Q, Jin S (2019) Significant wave height estimation from spaceborne cyclone-GNSS reflectometry. Remote Sens 11:584

    Article  Google Scholar 

  • Rani B, Srinivas K, Govardhan A (2014) Rainfall prediction with TLBO optimized ANN. J Sci Ind Res 73:643–647

    Google Scholar 

  • Rodriguez-Alvarez N, Munoz-Martin JF, Morris M (2023) Latest advances in the global navigation satellite system—reflectometry (GNSS-R) field. Remote Sens 15(8):2157

    Article  Google Scholar 

  • Roggenbuck O, Reinking J, Lambertus T (2019) Determination of significant wave heights using damping coefficients of attenuated GNSS SNR data from static and kinematic observations. Remote Sens 11:409

    Article  Google Scholar 

  • Ruf C, Balasubramaniam R (2019) Development of the CYGNSS geophysical model function for wind speed. IEEE J Sel Top Appl Earth Observ Remote Sens 12:66–77

    Article  Google Scholar 

  • Ruf CS et al (2016) New ocean winds satellite mission to probe hurricanes and tropical convection. Bull Amer Meteorol so 97:385–395

    Article  Google Scholar 

  • Ruf CS, Gleason S, Mckague DS (2018) Assessment of CYGNSS wind speed retrieval uncertainty. IEEE J Sel Top Appl Earth Observ Remote Sens 12:87–97

    Article  Google Scholar 

  • Soisuvarn S, Jelenak Z, Said F, Chang PS, Egido A (2016) The GNSS reflectometry response to the ocean surface winds and waves. IEEE J Sel Top Appl Earth Observ Remote Sens 9:4678–4699

    Article  Google Scholar 

  • Soulat F, Caparrini M, Germain O, Lopez-Dekker P, Taani M, Ruffini G (2004) Sea state monitoring using coastal GNSS-R. Geophys Res Lett. https://doi.org/10.1029/2004GL020680

    Article  Google Scholar 

  • Stogryn A (1970) Equations for calculating the dielectric constant of saline water. IEEE Trans Microw Theory Tech 19:733–736

    Article  Google Scholar 

  • Voronovich AG, Zavorotny VU (2017) Bistatic radar equation for signals of opportunity revisited. IEEE Trans Geosci Remote Sens 56:1959–1968

    Article  Google Scholar 

  • Wan W et al (2021) Initial evaluation of the first Chinese GNSS-R mission BuFeng-1 A/B for soil moisture estimation. IEEE Geosci Remote Sens Lett 19:1–5

    Google Scholar 

  • Wang C, Yu K, Zhang K, Bu J, Qu F (2022a) Significant wave height retrieval based on multi-variable regression models developed with CYGNSS data. IEEE Trans Geosci Remote Sens 61:4200415

    Google Scholar 

  • Wang F, Yang D, Yang L (2022b) Retrieval and assessment of significant wave height from CYGNSS mission using neural network. Remote Sens 14(15):3666

    Article  Google Scholar 

  • Wang T, Ruf C, Gleason S, McKague D, O’Brien A, Block B (2020) Monitoring GPS EIRP for CYGNSS level 1 calibration. In 2020 IEEE international geoscience and remote sensing symposium, pp 6293–6296

  • Zavorotny VU, Voronovich AG (2000) Scattering of GPS signals from the ocean with wind remote sensing application. IEEE Trans Geosci Remote Sens 38:951–964

    Article  Google Scholar 

  • Zhu Y, Guo F, Zhang X (2022) Effect of surface temperature on soil moisture retrieval using CYGNSS. Int J Appl Earth Obs Geoinf 112:102929

    Google Scholar 

Download references

Acknowledgements

We express our gratitude to the CYGNSS team for providing the Level 1 data, which is publicly accessible via the NASA EOSDIS Physical Oceanography Distributed Active Archive Center. In addition, we would like to thank the University of Hawaii for providing the SSS data, and ECMWF for providing the SWH data.

Funding

This research was supported by the National Science Fund for Distinguished Young Scholars (Grant No. 41825009), the National Natural Science Foundation of China (Grant No. 42074029), and the Fundamental Research Funds for the Central Universities (Grant No. 2042023kfyq01).

Author information

Authors and Affiliations

Authors

Contributions

Conceptualization, ZL and FG; methodology, ZL; software, YG; validation, ZL, FG, ZZ; formal analysis, ZL, XZ and FG; investigation, ZL; resources, ZL and FG; data curation, ZL; writing—original draft preparation, ZL; writing—review and editing, FG and ZL; visualization, ZL; supervision, FG; project administration, FG, XZ; funding acquisition, FG, XZ.

Corresponding author

Correspondence to Fei Guo.

Ethics declarations

Competing interests

The authors declare no competing interests.

Conflict of interest

The authors declare no conflict of interest.

Ethical approval

Research don’t involving Human Participants and/or Animals.

Consent for publication

All authors have read and agreed to the published version of the manuscript.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Li, Z., Guo, F., Zhang, X. et al. Analysis of factors influencing significant wave height retrieval and performance improvement in spaceborne GNSS-R. GPS Solut 28, 64 (2024). https://doi.org/10.1007/s10291-023-01605-3

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s10291-023-01605-3

Keywords

Navigation