|
|
Cite this paper: |
|
|
WANG Li, WU Xiongbin, MA Ketao, TIAN Yun, FEI Yuejun. Elimination of the impact of vessels on ocean wave height inversion with X-band wave monitoring radar[J]. Journal of Oceanology and Limnology, 2016, 34(5): 1114-1121 |
|
|
|
|
|
|
|
Elimination of the impact of vessels on ocean wave height inversion with X-band wave monitoring radar |
|
| WANG Li1, WU Xiongbin1, MA Ketao1, TIAN Yun1, FEI Yuejun2 |
|
1 School of Electronic Information, Faculty of Radio Oceanography, Wuhan University, Wuhan 430072, China;
2 Marine Forecast Center of East China Sea, East China Sea Branch, State Oceanic Administration, Shanghai 200081, China |
|
| Abstract: |
| Directional wave spectra and integrated wave parameters can be derived from X-band radar sea surface images. A vessel on the sea surface has a significant influence on wave parameter inversions that can be seen as intensive backscatter speckles in X-band wave monitoring radar sea surface images. A novel algorithm to eliminate the interference of vessels in ocean wave height inversions from X-band wave monitoring radar is proposed. This algorithm is based on the characteristics of the interference. The principal components (PCs) of a sea surface image sequence are extracted using empirical orthogonal function (EOF) analysis. The standard deviation of the PCs is then used to identify vessel interference within the image sequence. To mitigate the interference, a suppression method based on a frequency domain geometric model is applied. The algorithm framework has been applied to OSMAR-X, a wave monitoring system developed by Wuhan University, based on nautical X-band radar. Several sea surface images captured on vessels by OSMAR-X are processed using the method proposed in this paper. Inversion schemes are validated by comparisons with data from in situ wave buoys. The root-mean-square error between the significant wave heights (SWH) retrieved from original interference radar images and those measured by the buoy is reduced by 0.25 m. The determinations of surface gravity wave parameters, in particular SWH, confirm the applicability of the proposed method. |
|
| Key words:
X-band wave monitoring radar|vessel interference|empirical orthogonal function (EOF)|significant wave heights (SWH)|frequency domain geometric model
|
|
| Received: 2015-03-29 Revised: 2015-05-22 |
|
|
|
|
References:
Alpers W, Hasselmann K. 1982. Spectral signal to clutter and thermal noise properties of ocean wave imaging synthetic aperture radars. International Journal of Remote Sensing, 3(4):423-446.
An J Q, Huang W M, Gill E W. 2015. A self-adaptive waveletbased algorithm for wave measurement using nautical radar. IEEE Transactions on Geoscience and Remote Sensing, 53(1):567-577.
Atanassov V, Rosenthal W, Ziemer F. 1985. Removal of ambiguity of two-dimensional power spectra obtained by processing ship radar images of ocean waves. Journal of Geophysical Research, 90(C1):1 061-1 067.
Björnsson H, Venegas S A. 1997. A manual for EOF and SVD analyses of climatic data. CCGCR Rep., 97(1):1-52.
Chen Z B, He Y J, Zhang B, Qiu Z F. 2014a. A new algorithm to retrieve wave parameters from marine X-band radar image sequences. IEEE Transactions on Geoscience and Remote Sensing, 52(7):4 083-4 091.
Chen Z B, He Y J, Zhang B, Qiu Z F. 2014b. A new method to retrieve significant wave height from X-band marine radar image sequences. International Journal of Remote Sensing, 35(11-12):4 559-4 571.
Cui L M, He Y J, Shen H, Lü H B. 2010. Measurements of ocean wave and current field using dual polarized X-band radar. Chinese Journal of Oceanology and Limnology, 28(5):1 021-1 028.
Dankert H, Rosenthal W. 2004. Ocean surface determination from X-band radar-image sequences. Journal of Geophysical Research, 109(C4):1-11.
Fujikaw T, Kojima T. 2010. Radar device and rain/snow area detecting device. Japan, US2010207809 (A1). 2010-08-19.
Gangeskar R. 2000. An adaptive method for estimation of wave height based on statistics of sea surface images. In:Proceedings of IEEE International Geoscience and Remote Sensing Symposium. IEEE, Honolulu, HI, USA. 1:255-259.
Gangeskar R. 2012. Ocean current estimated from X-band radar sea surface images. IEEE Transactions on Geoscience and Remote Sensing, 40(4):783-792.
Ludeno G, Flampouris S, Lugni C, Soldovieri F. 2014. A novel approach based on marine radar data analysis for highresolution bathymetry map generation. IEEE Transactions on Geoscience and Remote Sensing Letters, 11(1):234-238.
Lund B, Graber H C, Romeiser R. 2012. Wind retrieval from shipborne nautical X-band radar data. IEEE Transactions on Geoscience and Remote Sensing Letters, 50(10):3 800-3 811.
Maa J P Y, Ha H K. 2005. X-band Radar Wave Observation System. College of William and Mary, Herndon, VA, US.p.52-53.
Monahan A H, Fyfe J C, Ambaum M H P, Stephenson D B, North G R. 2009. Empirical orthogonal functions:the medium is the message. Journal of Climate, 22(24):6 501-6 514.
Nieto-Borge J C, Hessner K, Jarabo-Amores P, de la MataMoya D. 2008. Signal-to-noise ratio analysis to estimate ocean wave heights from X-band marine radar image time series. IET Radar, Sonar & Navigation, 2(1):35-41.
Nieto-Borge J C, Soares C G. 2000. Analysis of directional wave fields using X-band navigation radar. Coastal Engineering, 40(4):375-391.
North G R, Bell T L, Cahalan R F, Moeng F J. 1982. Sampling errors in the estimation of empirical orthogonal functions.Monthly Weather Review, 110(7):699-706.
Pegram G, Llort X, Sempere-Torres D. 2011. Radar rainfall:separating signal and noise fields to generate meaningful ensembles. Atmospheric Research, 100(2-3):226-236.
Pestoriza V, Nunez A, Marino P, Fontá n F P. 2010. Rain-cell identification and modeling for propagation studies from weather radar images. IEEE Antennas and Propagation Magazine, 52(5):117-130.
Seemann J, Senet C M, Dankert H, Hatten H, Ziemer F. 1999.Radar image sequence analysis of inhomogeneous water surfaces. In:Proceedings of Conference on Applications of Digital Image Processing XXⅡ.SPIE, Denver, CO, USA.
Senet C M, Seemann J, Flampouris S, Ziemer F. 2008.Determination of bathymetric and current maps by the method DISC based on the analysis of nautical X-band radar image sequences of the sea surface (November 2007). IEEE Transactions on Geoscience and Remote Sensing Letters, 46(8):2 267-2 279.
Serafino F, Lugni C, Soldovieri F. 2010. A novel strategy for the surface current determination from marine X-band radar data. IEEE Transactions on Geoscience and Remote Sensing Letters, 7(2):231-235.
Wu Y Q, Wu X B, Chen F, Ke H Y. 2007. Basic analysis on the extraction of ocean dynamic parameters with an X-band radar. Journal of Remote Sensing, 11(6):817-825. (in Chinese with English abstract)
Young I R, Rosenthal W, Ziemer F. 1985. A three-dimensional analysis of marine radar images for the determination of ocean wave directionality and surface currents. Journal of Geophysical Research, 90(C1):1 049-1 059.
Ziemer F. 1995. An instrument for the survey of the directionality of the ocean wave field. In:Proceedings of.Workshop on Operational Ocean Monitoring Using Surface Based Radars. WMO/IOC Report, Geneva, 32:81-87.
|
|
|
|