摘要
海浪波谱仪(surface waves Investigation and Monitoring,swIM)是新型的海浪信息探测雷达,它以真实孔径雷达为基础,配置六个波束圆锥扫描,波束中心入射角分别为O。,2。,4。,6。,8。和10。。其星下点波束的工作机制相当于一个雷达高度计,而侧视旋转波束通过增加相应的工作模式和功能模块,实现海洋波浪方向谱的测量。海浪波谱仪可获得全球大面积、长时间序列的标准化雷达后向散射截面(NRcs,0.)、海浪方向谱、风速和波高信息。本文对海浪波谱仪海浪遥感探测方法及应用基础研究的若干问题进行了研究与探讨。
首先,利用电磁波散射理论,建立了从海浪方向谱映射到海浪波谱仪后向散射截面的模型。并利用目前唯一能提供Ku波段小入射角NRcs的传感器一一降雨雷达(Precipitation Radar,PR)的散射测量数据对散射模型进行了检验。
基于建立的海浪波谱仪散射模型,论述了由海浪波谱仪散射信号反演海浪方向谱的方法。对不同系统参数、不同海况、不同入射角下的海浪波谱仪海浪方向谱反演进行了仿真。编制了面向对象人机交互海浪波谱仪仿真软件。仿真结果显示,误差部在允许范围内。
利用线性回归法和多入射角组合法,反演了高斯斜率分布中的斜率方差和天底点0。。结果显示,这两种不同的反演方法反演得到的观测方向上的斜率方差的差别在O.0025以内。研究了不同海况下,斜率方差和天底点0。与风速和方位向的关系。
利用降雨雷达0。数据研究了小入射角下0。随方位向的变化,重点分析了0。的顺风逆风不对称性(uDA)和由于风向不同导致0。变化(ucA)的幅度与海况、入射角的关系,并利用海浪斜率概率密度函数中的高阶项参量一偏度来解释了这种与散射计相反的不对称性。研究了涌浪对uDA和ucA的影响,并讨论了其在海浪波谱仪上的应用。
利用降雨雷达与浮标匹配数据,研究了Ku波段HH极化0。与海面风、浪参数(风速、风向、波高、波长、波周期、波陡、波龄)的相关性。建立了不同入射角下0。分别与海面风速(U0)、有效波高(H)、波陡(&。)和积分波龄(Ba)的经验关系。对从单个0。直接反演各个风、浪参数的可行性进行了全面的分析,包括灵敏度分析、最佳的雷达入射角和海况,最佳的辅助信息等。
建立了海浪波谱仪多入射角数据获取海面风速的新方法。该方法考虑了海浪斜率对NRcs与风速之间关系的影响,并且不需要波高、波龄等辅助信息。新的风速反演方法均方根误差为1.36 m/s,提高了以往降雨雷达的风速反演精度。
The instrument SWIM (Surface Waves Investigation and Monitoring) is the first ever space radar concept that mainly dedicated to the measurement of ocean waves directional spectra through multi-azimuth and multi-incidence observations. SWIM is real aperture radar in Ku-band pointing sequentially at six different incidences (from 0 to 10 ). Nadir beam works like satellite altimeter. SWIM instrument will provide global long time observation of three kinds of measurements: the from nadir to 10 , the wave directional spectra, the significant wave height and wind speed. This thesis focuses on SWIM ocean wave remote sensing technology and its application basic research on other information retrieval.
At low incidence, the sea surface scattering mechanism and ocean wave remote sensing technique is different from previous active microwave radars. We developed the forward transfer function from directional wave spectrum to radar NRCS based on Kirchhoff approximation and two-scale method. Precipitation radar (PR) on the Tropical Rainfall Mapping Mission (TRMM) provides radar backscattering cross section near nadir. The model is tested using measurement from PR.
Based on the scattering mechanism, the thesis presents the algorithm of inversion ocean wave directional spectra from SWIM signal. Radar preferences and output resolution and accuracy are analyzed. Then end-to-end simulations are performed to assess the performances of the system in terms of different radar preferences, sea states and incidence angles. The end-to-end SWIM simulator is developed, which includes radar parameters setup panel, sea states setup panel, radar signal display panel, inversion results display panel and err display panel. NRCS is proportional to the probability density function (PDF) of surface wave slopes at low incidence angles. Two methods are proposed to retrieve filtered slope variance under Gaussian slope PDF assumptions. The relationships between filtered slope variance and surface conditions (wind and waves) are investigated.
Due to a lack of SWIM data, PR measurements are used to present the first results from a study of upwind/downwind asymmetry (UDA) and upwind/crosswind anisotropy (UCA) of the low incidence microwave backscattering from satellite observations. Incidence angle and wind speed dependence were a particular focus. The UDA is explained by the use of non-Gaussian statistics of the sea surface slope. Sensitivities to sea state are also analyzed. The application to SWIM wind vector retrieval is also discussed.
The potential utility of this new radar for direct wind and wave measurement is of great interest. By using nine years of collocated PR and buoy data, the relationships between Ku-band NRCS and integrated wind and wave parameters (e.g., wave period, significant wave height, wave steepness, wave age) at low incidence angles are analyzed for different sea states. Empirical tabular functions relating to sea surface wind speed above 10 m (U10), significant wave height (Hs), wave steepness ( a) and integral wave age ( a), respectively, are developed for incidence angles from 0 (nadir) to 18 . Besides, the potential for inverting these parameters directly from a single is investigated. Those investigations can serve to design directly models relating SWIM NRCS to ocean wind and wave measurements.
The above analyses clearly demonstrate that radar backscattering correlates with both the near-surface wind speed and the sea surface wave slope at low incidence angles. Multi-incidence angles PR data are used to retrieve sea surface wave slope parameter and normalized nadir backscattering. After that, an empirical wind speed model was developed based on those two parameters that attenuates the surface tilting effect. The inversion is defined using a multilayer perceptron neural network with radar-derived backscatter and surface wave slope parameter as inputs. Results show the root mean square err (RMSE) between wind speeds retrieved and in situ buoy observations is 1.36 m/s, bias is nearly zero, revealing good agreements in wind speed estimations. The method can be directly applied to SWIM.
引文
[1] Amiot, T., C. Tison, V. Enjolras, et al., Directional wave spectrum estimation by SWIM instrument on CFOSAT, 2009 IEEE International Geoscience and Remote Sensing Symposium, vol. 1-5, 2009.
[2] Aouf, L., J. M. Lefevre, and D. Hauser, Assimilation of directional wave spectra in the wave model WAM: An impact study from synthetic observations in preparation for the SWIMSAT satellite mission, Journal of Atmospheric and Oceanic Technology, vol. 23, no. 3, pp. 448-463, 2006.
[3] Bao, M., A nonlinear integral transform between ocean wave spectra and phase image spectra of a cross-track interferometric SAR, 1999 International Geoscience and Remote Sensing Symposium, vol. 5, pp. 2619-2621, 1999.
[4] Bao, M. Q., W. Alpers, and C. Bruning, A new nonlinear integral transform relating ocean wave spectra to phase image spectra of an along-track interferometric synthetic aperture radar, IEEE Transactions on Geoscience and Remote Sensing, vol. 37, no. 1, pp. 461-466, 1999.
[5] Barrick, D. E., Rough surface scattering based on specular point theory, IEEE Transactions on Antennas and Propagation, vol. Ap16, no. 4, pp. 449-454, 1968.
[6] Bauer, E., S. Hasselmann, and C. Bruning, Application of wave spectra retrieved from ERS-1 SAR wave mode spectra in a wind- and wave-data assimilation system, 1995 International Geoscience and Remote Sensing Symposium, Vols 1-3, pp. 1643-1645, 1995.
[7] Breivik, L. A., M. Reistad, H. Schyberg, et al., Assimilation of ERS SAR wave spectra in an operational wave model, Journal of Geophysical Research-Oceans, vol. 103, no. C4, pp. 7887-7900, 1998.
[8] Breon, F. M., and N. Henriot, Spaceborne observations of ocean glint reflectance and modeling of wave slope distributions, Journal of Geophysical Research-Oceans, vol. 111, no. C6, 2006.
[9] Caires, S., A. Sterl, and C. P. Gommenginger, Global ocean mean wave period data: Validation and description, Journal of Geophysical Research-Oceans, vol. 110, no. C2, 2005.
[10] Calvary, P., and L. Phalippou, Preliminary design of the SWIMSAT radar for the measurement of ocean wave spectra, Geoscience and Remote Sensing Symposium, vol. 2, pp. 777-779, 2002.
[11] Caudal, G., E. Dinnat, and J. Boutin, Absolute calibration of radar altimeters:Consistency with electromagnetic modeling, Journal of Atmospheric and Oceanic Technology, vol. 22, no. 6, pp. 771-781, 2005.
[12] Center, E. O., TRMM data users handbook, NASDA, ed., Earth observation center, National space development agency of Japan, 2001.
[13] Chapron, B., D. Vandemark, and F. C. Jackson, Airborne measurements of the oceans Ku-band radar cross-section at low Incidence angles, Atmosphere-Ocean, vol. 32, no. 1, pp. 179-193, 1994.
[14] Chen, G., and H. Lin, Impacts of collocation window on the accuracy of altimeter/buoy wind-speed comparison - a simulation study, International Journal of Remote Sensing, vol. 22, no. 1, pp. 35-44, 2001.
[15] Chen, G., B. Chapron, R. Ezraty, et al., A global view of swell and wind sea climate in the ocean by satellite altimeter and scatterometer, Journal of Atmospheric and Oceanic Technology, vol. 19, no. 11, pp. 1849-1859, 2002a.
[16] Chen, G., B. Chapron, R. Ezraty, et al., A dual-frequency approach for retrieving sea surface wind speed from TOPEX altimetry, Journal of Geophysical Research-Oceans, vol. 107, no. C12, pp. -, 2002b.
[17] Cheng, Y. C., Q. Xu, Y. G. Liu, et al., An analytical algorithm with a wave age factor for altimeter wind speed retrieval, International Journal of Remote Sensing, vol. 29, no. 19, pp. 5699-5716, 2008.
[18] Cox, C., and W. Munk, Measurement of the Roughness of the Sea Surface from Photographs of the Suns Glitter, Journal of the Optical Society of America, vol. 44, no. 11, pp. 838-850, 1954a.
[19] Cox, C., and W. Munk, Statistics of the sea surface derived from sun glitter, Journal of Marine Research, vol. 13, no. 2, pp. 198-227, 1954b.
[20] Cox, C., and W. Munk, Slopes of the sea surface deduced from photographs of sun glitter, Bulletin of the Scripps Institution of Oceanography, vol. 6, no. 9, pp. 401-488, 1956.
[21] Danièle, H., T. Podvin, M. Dechambre, et al., Polarimetric measurements over the sea-surface with the airborne STORM radar in the context of the geophysical validation of the ENVISAT ASAR, Proceedings of the Workshop on POLinSAR - Applications of SAR Polarimetry and Polarimetric Interferometry (ESA SP-529), pp. 63-71, 2003.
[22] Delasheras, M. M., G. Burgers, and P. A. E. M. Janssen, Variational wave data assimilation in a 3rd-generation wave model, Journal of Atmospheric and Oceanic Technology, vol. 11, no. 5, pp. 1350-1369, 1994.
[23] Donelan, M. A., and W. J. Pierson, Radar scattering and equilibrium rangesin wind-generated waves with application to scatterometry, Journal of Geophysical Research-Oceans, vol. 92, no. C5, pp. 4971-5029, 1987.
[24] Durden, S. L., and J. F. Vesecky, A physical radar cross-section model for a wind-driven sea with swell, IEEE Journal of Oceanic Engineering, vol. 10, no. 4, pp. 445-451, 1985.
[25] Elfouhaily, T., B. Chapron, K. Katsaros, et al., A unified directional spectrum for long and short wind-driven waves, Journal of Geophysical Research-Oceans, vol. 102, no. C7, pp. 15781-15796, 1997.
[26] Enjolras, V., E. Caubet, J. Richard, et al., SWIM: a multi-incidence beams Ku-band real aperture radar for the observation of the ocean wave field spectra. pp. 236-239.
[27] Enjolras, V., L. Rey, L. Cros, et al., SWIM: a state of the art multi-incidence beams ku-band waves scatterometer to go beyond current radar systems, 2009 IEEE International Geoscience and Remote Sensing Symposium, vol. 1-5, pp. 3741-3744, 2009a.
[28] Enjolras, V., L. Rey, L. Cros, et al., SWIM, a state of the art multi-incidence beams ku-band waves scatterometer to go beyond current radar systems, in 2009 IEEE International Geoscience and Remote Sensing Symposium, Capetown, South Africa, 2009b.
[29] Freilich, M. H., and B. A. Vanhoff, The relationship between winds, surface roughness, and radar backscatter at low incidence angles from TRMM precipitation radar measurements, Journal of Atmospheric and Oceanic Technology, vol. 20, no. 4, pp. 549-562, 2003.
[30] Glazman, R. E., and A. Greysukh, Satellite altimeter measurements of surface wind, Journal of Geophysical Research-Oceans, vol. 98, no. C2, pp. 2475-2483, 1993.
[31] Gommenginger, C. P., M. A. Srokosz, P. G. Challenor, et al., Development and validation of altimeter wind speed algorithms using an extended collocated buoy/Topex dataset, IEEE Transactions on Geoscience and Remote Sensing, vol. 40, no. 2, pp. 251-260, 2002.
[32] Gommenginger, C. P., M. A. Srokosz, P. G. Challenor, et al., Measuring ocean wave period with satellite altimeters: A simple empirical model, Geophysical Research Letters, vol. 30, no. 22, 2003.
[33] Gourrion, J., D. Vandemark, S. Bailey, et al., A two-parameter wind speed algorithm for Ku-band altimeters, Journal of Atmospheric and Oceanic Technology, vol. 19, no. 12, pp. 2030-2048, 2002.
[34] Guo, J., Y. J. He, W. Perrie, et al., A new model to estimate significant waveheights with ERS-1/2 scatterometer data, Chinese Journal of Oceanology and Limnology, vol. 27, no. 1, pp. 112-116, 2009a.
[35] Guo, J., Y. J. He, X. Q. Chu, et al., Wave parameters retrieved from QuikSCAT data, Canadian Journal of Remote Sensing, vol. 35, no. 4, pp. 345-351, 2009b.
[36] Hasselmann, D. E., M. Dunckel, and J. A. Ewing, Directional wave spectra observed during Jonswap 1973, Journal of Physical Oceanography, vol. 10, no. 8, pp. 1264-1280, 1980.
[37] Hasselmann, K., and S. Hasselmann, On the Nonlinear Mapping of an Ocean Wave Spectrum into a Synthetic Aperture Radar Image Spectrum and Its Inversion, Journal of Geophysical Research-Oceans, vol. 96, no. C6, pp. 10713-10729, 1991.
[38] Hasselmann, K., T. Barnett, E. Bouws, et al., Measurements of wind-wave growth and swell decay during the Joint North Sea Wave Project (JONSWAP), Dtsch. Hydrogr. Z. Suppl. A, vol. 8, no. 12, pp. 289-300, 1973.
[39] Hasselmann, S., C. Bruning, K. Hasselmann, et al., An improved algorithm for the retrieval of ocean wave spectra from synthetic aperture radar image spectra, Journal of Geophysical Research-Oceans, vol. 101, no. C7, pp. 16615-16629, 1996.
[40] Hauser, D., VAGSAT - a proposal for a small satellite mission for the measurement of ocean wave spectra with a real-aperture radar, 1994 IEEE International Geoscience and Remote Sensing Symposium, vol. 1-4, pp. 1516-1518, 1994.
[41] Hauser, D., G. Caudal, and G.-J. Rijckeneierg, Measurements of ocean wave spectra with the RESSAC airborne radar, IEEE Geoscience and Remote Sensing Letters, vol. 4, pp. 2021-2024, 1991a.
[42] Hauser, D., G. Caudal, and G. J. Rijckenberg, Measurements of ocean wave spectra with the RESSAC airborne radar, IGARSS 91 - Remote Sensing : Global Monitoring for Earth Management, Vols 1-4, pp. 2021-2024, 1991b.
[43] Hauser, D., G. Caudal, and L. K. Shay, Behavior of the ocean radar cross-section at low incidence, observed in the vicinity of the Gulf-stream, IEEE Transactions on Geoscience and Remote Sensing, vol. 33, no. 1, pp. 162-171, 1995.
[44] Hauser, D., E. Soussi, E. Thouvenot, et al., SWIMSAT: A real-aperture radar to measure directional spectra of ocean waves from space - Main characteristics and performance simulation, Journal of Atmospheric and Oceanic Technology, vol. 18, no. 3, pp. 421-437, 2001.
[45] Hauser, D., G. Caudal, S. Guimbard, et al., A study of the slope probability density function of the ocean waves from radar observations, Journal of Geophysical Research-Oceans, vol. 113, no. C2, 2008.
[46] Hauser, D., G. Caudal, S. Guimbard, et al., Reply to comment by Paul A. Hwang on "A study of the slope probability density function of the ocean waves from radar observations'' by D. Hauser et al., Journal of Geophysical Research-Oceans, vol. 114, 2009.
[47] Hauser, D., G. Caudal, G. J. Rijckenberg, et al., RESSAC: a new airborne FM/CW radar ocean wave spectrometer, IEEE Transactions on Geoscience and Remote Sensing, vol. 30, no. 5, pp. 981-995, 1992.
[48] Hauser, D., T. Podvin, M. Dechambre, et al., STORM: A new airborne polarimetric real-aperture radar for earth observations, Applications of SAR Polarimetry and Polarimetric Interferometry.
[49] He, Y. J., A parametric method of retrieving ocean wave spectra from synthetic aperture radar images, Chinese Science Bulletin, vol. 44, no. 13, pp. 1218-1224, 1999.
[50] He, Y. J., and W. Alpers, On the nonlinear integral transform of an ocean wave spectrum into an along-track interferometric synthetic aperture radar image spectrum, Journal of Geophysical Research-Oceans, vol. 108, no. C6, 2003.
[51] He, Y. J., H. Shen, and W. Perrie, Remote sensing of ocean waves by polarimetric SAR, Journal of Atmospheric and Oceanic Technology, vol. 23, no. 12, pp. 1768-1773, 2006.
[52] Hersbach, H., A. Stoffelen, and S. de Haan, An improved C-band scatterometer ocean geophysical model function: CMOD5, Journal of Geophysical Research-Oceans, vol. 112, no. C3, pp. 1-18, 2007.
[53] Hesany, V., W. J. Plant, and W. C. Keller, The normalized radar cross section of the sea at 10 incidence, IEEE Transactions on Geoscience and Remote Sensing, vol. 38, no. 1, pp. 64-72, 2000.
[54] Hwang, P. A., Comment on "A study of the slope probability density function of the ocean waves from radar observations'' by D. Hauser et al., Journal of Geophysical Research-Oceans, vol. 114, 2009.
[55] Hwang, P. A., W. J. Teague, G. A. Jacobs, et al., A statistical comparison of wind speed, wave height, and wave period derived from satellite altimeters and ocean buoys in the Gulf of Mexico region, Journal of Geophysical Research-Oceans, vol. 103, no. C5, pp. 10451-10468, 1998.
[56] Isoguchi, O., and M. Shimada, An L-band ocean geophysical model functionderived from PALSAR, IEEE Transactions on Geoscience and Remote Sensing, vol. 47, no. 7, pp. 1925-1936, 2009.
[57] Jackson, F., W. Walton, and C. Peng, A comparison of in situ and airborne radar observations of ocean wave directionality, Journal of Geophysical Research, vol. 90, no. C1, pp. 1005-1018, 1985a.
[58] Jackson, F. C., An analysis of short pulse and dual frequency radar techniques for measuring ocean wave spectra from satellites, Radio Science, vol. 16, no. 6, pp. 1385-1400, 1981.
[59] Jackson, F. C., The physical basis for estimating wave-energy spectra with the radar ocean-wave spectrometer, Johns Hopkins Apl Technical Digest, vol. 8, no. 1, pp. 70-73, 1987a.
[60] Jackson, F. C., The radar ocean-wave spectrometer, Johns Hopkins Apl Technical Digest, vol. 8, no. 1, pp. 116-127, 1987b.
[61] Jackson, F. C., Directional spectra from the radar ocean wave spectrometer during LEWEX, Directional Ocean Wave Spectra, pp. 91-97, 1991.
[62] Jackson, F. C., and C. Y. Peng, Imaging radar observations of directional properties of ocean waves - comment, Journal of Geophysical Research-Oceans, vol. 90, no. Nc4, pp. 7367-7370, 1985.
[63] Jackson, F. C., W. T. Walton, and P. L. Baker, Aircraft and satellite measurement of ocean wave directional spectra using scanning-beam microwave radars, Journal of Geophysical Research-Oceans, vol. 90, no. Nc1, pp. 987-1004, 1985b.
[64] Kanevsky, M. B., Radar imaging of the ocean waves: Elsevier Science, 2008.
[65] Karaev, V., M. Kanevsky, and E. Meshkov, The effect of sea surface slicks on the Doppler spectrum width of a backscattered microwave signal, Sensors, vol. 8, no. 6, pp. 3780-3801, 2008a.
[66] Karaev, V., M. Kanevsky, E. Meshkov, et al., Measurement of wind wave slope variance with the radar having a knife-like antenna pattern, Sixth Int Kharkov Symposium on Physics and Engineering of Microwaves, Millimeter and Submillimeter Waves/Workshop on Terahertz Technologies, Vols 1 and 2, pp. 424-426, 2007.
[67] Karaev, V. Y., M. B. Kanevsky, P. D. Cotton, et al., Is it possible to measure ocean surface slopes with a microwave radar at nadir probing?, International Journal of Remote Sensing, vol. 23, no. 16, pp. 3251-3262, 2002a.
[68] Karaev, V. Y., M. B. Kanevsky, E. M. Meshkov, et al., Measurement of thevariance of water surface slopes by a radar: verification of algorithms, Radiophysics and Quantum Electronics, vol. 51, no. 5, pp. 360-371, 2008b.
[69] Karaev, V. Y., M. B. Kanevsky, G. N. Balandina, et al., A Doppler knife-beam radar altimeter concept for novel sea state parameters, 2003 International Geoscience and Remote Sensing Symposium, Vols I - Vii, Proceedings, vol. I - Vii, pp. 4323-4325, 2003.
[70] Karaev, V. Y., M. B. Kanevsky, G. N. Balandina, et al., The concept of a microwave radar with an asymmetric knife-like beam for the remote sensing of ocean waves, Journal of Atmospheric and Oceanic Technology, vol. 22, no. 11, pp. 1809-1820, 2005.
[71] Karaev, V. Y., M. B. Kanevsky, G. N. Balandina, et al., On the problem of the near ocean surface wind speed retrieval by radar altimeter: a two-parameter algorithm, International Journal of Remote Sensing, vol. 23, no. 16, pp. 3263-3283, 2002b.
[72] Karaev, V. Y., M. B. Kanevsky, G. N. Balandina, et al., A rotating knife-beam altimeter for wide-swath remote sensing of ocean: Wind and waves, Sensors, vol. 6, no. 6, pp. 620-642, 2006.
[73] Klein, L. A., and C. T. Swift, Improved model for dielectric-constant of sea-water at microwave-frequencies, IEEE Transactions on Antennas and Propagation, vol. 25, no. 1, pp. 104-111, 1977.
[74] Kshatriya, J., A. Sarkar, and R. Kumar, Determination of ocean wave period from altimeter data using wave-age concept Marine Geodesy, vol. 28, no. 1, pp. 71-79, 2005.
[75] Kudryavtsev, V., D. Hauser, G. Caudal, et al., A semiempirical model of the normalized radar cross-section of the sea surface - 1. Background model, Journal of Geophysical Research-Oceans, vol. 108, no. C1, 2003.
[76] Kummerow, C., W. Barnes, T. Kozu, et al., The Tropical Rainfall Measuring Mission (TRMM) sensor package, Journal of Atmospheric and Oceanic Technology, vol. 15, no. 3, pp. 809-817, 1998.
[77] Kummerow, C., J. Simpson, O. Thiele, et al., The status of the Tropical Rainfall Measuring Mission (TRMM) after two years in orbit, Journal of Applied Meteorology, vol. 39, no. 12, pp. 1965-1982, 2000.
[78] Lefevre, J. M., J. Barckicke, and Y. Menard, A significant wave height dependent function for TOPEX/POSEIDON wind-speed retrieval, Journal of Geophysical Research-Oceans, vol. 99, no. C12, pp. 25035-25049, 1994.
[79] Li, L., E. Im, L. N. Connor, et al., Retrieving ocean surface wind speed from the TRMM precipitation radar measurements, IEEE Transactions onGeoscience and Remote Sensing, vol. 42, no. 6, pp. 1271-1282, 2004.
[80] Li, X., S. Lehner, and T. Bruns, Ocean wave integral parameter measurements using ENVISAT ASAR wave mode data, IEEE Transactions on Geoscience and Remote Sensing, no. 99, pp. 1-20, 2010.
[81] Liao, L., and R. Meneghini, Validation of TRMM precipitation radar through comparison of its multiyear measurements with ground-based radar, Journal of Applied Meteorology and Climatology, vol. 48, no. 4, pp. 804-817, 2009a.
[82] Liao, L., and R. Meneghini, Changes in the TRMM version-5 and version-6 precipitation radar products due to orbit boost, Journal of the Meteorological Society of Japan, vol. 87, pp. 93-107, 2009b.
[83] Lin, W. M., X. L. Dong, Y. Zhou, et al., Simulation and optimization of the performance of space-borne radar ocean wave spectrometer, 2009 IEEE International Geoscience and Remote Sensing Symposium, Vols 1-5, pp. 2095-2098, 2009.
[84] Lorenzo, J., F. Demeestere, J. Brossier, et al., Next generation of multi beam rotating antenna on SWIM scatterometer, 2010 IEEE International Geoscience and Remote Sensing Symposium, pp. 3478-3481, 2010.
[85] Mackay, E. B. L., C. H. Retzler, P. G. Challenor, et al., A parametric model for ocean wave period from K-u band altimeter data, Journal of Geophysical Research-Oceans, vol. 113, no. C3, pp. 16, 2008.
[86] Mastenbroek, C., and C. F. De Valk, A semiparametric algorithm to retrieve ocean wave spectra from synthetic aperture radar, Journal of Geophysical Research-Oceans, vol. 105, no. C2, pp. 3497-3516, 2000.
[87] Miller, L. S., The application of near-altimetry and oceanographic remote sensing, IEEE Transactions on Geoscience and Remote Sensing, vol. 21, no. 1, pp. 16-24 1983.
[88] Mitsuyasu, H., F. Tasai, T. Suhara, et al., Observations of the directional spectrum of ocean waves using a cloverleaf buoy, Journal of Physical Oceanography, vol. 5, no. 4, pp. 750-760, 1975.
[89] Mouche, A., D. Hauser, G. Caudal, et al., Use of Dual Polarization Radar Measurements to understand the azimuth behavior of the sea surface backscattered signal, 2006 IEEE International Geoscience and Remote Sensing Symposium, Vols 1-8, pp. 1867-1870, 2006a.
[90] Mouche, A. A., D. Hauser, and V. Kudryavtsev, Radar scattering of the ocean surface and sea-roughness properties: A combined analysis from dual-polarizations airborne radar observations and models in C band, Journal of Geophysical Research-Oceans, vol. 111, no. C9, 2006b.
[91] Mouche, A. A., D. Hauser, J. F. Daloze, et al., Dual-polarization measurements at C-band over the ocean: Results from airborne radar observations and comparison with ENVISAT ASAR data, IEEE Transactions on Geoscience and Remote Sensing, vol. 43, no. 4, pp. 753-769, 2005.
[92] Mouche, A. A., B. Chapron, N. Reul, et al., Importance of the sea surface curvature to interpret the normalized radar cross section, Journal of Geophysical Research-Oceans, vol. 112, no. C10, pp. 1-12, 2007.
[93] Munk, W., An inconvenient sea truth: spread, steepness, and skewness of surface slopes, Annual Review of Marine Science, vol. 1, pp. 377-415, 2009.
[94] Pettersson, H., H. C. Graber, D. Hauser, et al., Directional wave measurements from three wave sensors during the FETCH experiment, Journal of Geophysical Research-Oceans, vol. 108, no. C3, 2003.
[95] Pierson, W. J., and L. Moskowitz, A proposed spectral form for fully developed wind seas based on the similarity theory of S. A. Kitaigorodsk, Journal of Geophysical Research, vol. 69, no. 24, pp. 5181-5190, 1964.
[96] Plant, W. J., A 2-scale model of short wind-generated waves and scatterometry, Journal of Geophysical Research-Oceans, vol. 91, no. C9, pp. 735-749, 1986.
[97] Quilfen, Y., J. Tournadre, and B. Chapron, Altimeter dual-frequency observations of surface winds, waves, and rain rate in tropical cyclone Isabel, Journal of Geophysical Research-Oceans, vol. 111, no. C1, 2006.
[98] Quilfen, Y., B. Chapron, F. Collard, et al., Relationship between ERS scatterometer measurement and integrated wind and wave parameters, Journal of Atmospheric and Oceanic Technology, vol. 21, no. 2, pp. 368-373, 2004a.
[99] Quilfen, Y., B. Chapron, F. Collard, et al., Calibration/validation of an altimeter wave period model and application to TOPEX/Poseidon and Jason-1 Altimeters, Marine Geodesy, vol. 27, no. 3, pp. 535-549, 2004b.
[100] Quilfen, Y., B. Chapron, A. Bentamy, et al., Global ERS 1 and 2 and NSCAT observations: Upwind/crosswind and upwind/downwind measurements, Journal of Geophysical Research-Oceans, vol. 104, no. C5, pp. 11459-11469, 1999.
[101] Qun, S., and S. Jinbao, Comparison of retrieving methods of ocean wave periods from satellite altimeter with buoy measurements, Chinese Journal of Oceanology and Limnology, vol. 24, no. 1, pp. 6-11, 2006.
[102] Ren, L., Z. H. Mao, H. Q. Huang, et al., Satellite-based RAR performance simulation for measuring directional ocean wave spectrum based on SARinversion spectrum, Acta Oceanologica Sinica, vol. 29, no. 4, pp. 13-20, 2010.
[103] Rijckenberg, G. J., R. Bernard, and G. Caudal, Radar measurement of directional ocean wave spectra at low incidence angles, International Journal of Remote Sensing, vol. 13, no. 16, pp. 2961-2974, 1992.
[104] Sarkar, A., R. Kumar, and M. Mohan, Estimation of ocean wave periods by spaceborne altimeters, Indian Journal of Marine Sciences, vol. 27, no. 1, pp. 43-45, 1998.
[105] Schulz-Stellenfleth, J., and S. Lehner, Ocean wave imaging using an airborne single pass across-track interferometric SAR, IEEE Transactions on Geoscience and Remote Sensing, vol. 39, no. 1, pp. 38-45, 2001.
[106] Schulz-Stellenfleth, J., T. Konig, and S. Lehner, An empirical approach for the retrieval of integral ocean wave parameters from synthetic aperture radar data, Journal of Geophysical Research-Oceans, vol. 112, no. C3, pp. 1-14, 2007.
[107] Schulz-Stellenfleth, J., J. Horstmann, S. Lehner, et al., Sea surface imaging with an across-track interferometric synthetic aperture radar: The SINEWAVE experiment, IEEE Transactions on Geoscience and Remote Sensing, vol. 39, no. 9, pp. 2017-2028, 2001.
[108] Soussi, E., and D. Hauser, Numerical simulation of the radar signal modulation due to the long ocean waves: Preparation of the VAGSAT mission, Oceans '96 MTS/IEEE, Conference Proceedings, Vols 1-3, Supplementary Proceedings, pp. 1516-1520, 1996.
[109] Stephen, H., S. Ahmad, T. C. Piechota, et al., Relating surface backscatter response from TRMM precipitation radar to soil moisture: results over a semi-arid region, Hydrology and Earth System Sciences, vol. 14, no. 2, pp. 193-204, 2010.
[110] Sun, J., and C. Guan, Parameterized first-guess spectrum method for retrieving directional spectrum of swell-dominated waves and huge waves from SAR images, Chinese Journal of Oceanology and Limnology, vol. 24, no. 1, pp. 12-20, 2006.
[111] Tison, C., G. Carayon, J. Lambin, et al., A spaceborne radar for directional wave spectrum estimation: first performance simulations, in IEEE International Geoscience and Remote Sensing Symposium, 2008. IGARSS 2008., Boston, MA,, 2008, pp. 247-350.
[112] Tison, C., T. Amiot, D. Hauser, et al., Directional wave spectrum estimation by SWIM instrument on CFOSAT, in 2009 IEEE International Geoscienceand Remote Sensing Symposium, Capetown, South Africa, 2009.
[113] Tison, C., T. Amiot, V. Enjolras, et al., Performance status of the wave scatterometer SWIM, 2010 IEEE International Geoscience and Remote Sensing Symposium, pp. 4170-4173, 2010.
[114] Tran, N., and B. Chapron, Combined wind vector and sea state impact on ocean nadir-viewing Ku- and C-band radar cross-sections, Sensors, vol. 6, no. 3, pp. 193-207, 2006.
[115] Tran, N., B. Chapron, and D. Vandemark, Effect of long waves on Ku-band ocean radar backscatter at low incidence angles using TRMM and altimeter data, IEEE Geoscience and Remote Sensing Letters, vol. 4, no. 4, pp. 542-546, 2007.
[116] Tran, N., O. Z. Zanife, B. Chapron, et al., Absolute calibration of Jason-1 and Envisat altimeter Ku-band radar cross sections from cross comparison with TRMM precipitation radar measurements, Journal of Atmospheric and Oceanic Technology, vol. 22, no. 9, pp. 1389-1402, 2005.
[117] Valenzuela, G., Theories for the interaction of electromagnetic and ocean wave-a review, Boundary Layer Meteorology, vol. 13, pp. 61-85, 1978.
[118] Vandemark, D., F. C. Jackson, E. J. Walsh, et al., Airborne radar measurements of ocean wave spectra and wind-speed during the grand-banks ERS-1 SAR wave experiment, Atmosphere-Ocean, vol. 32, no. 1, pp. 143-178, 1994.
[119] Walsh, E., D. Vandemark, C. Friehe, et al., Measuring sea surface mean square slope with a 36-GHz scanning radar altimeter, Journal of Geophysical Research-Oceans, vol. 103, no. C6, pp. 12587-12601, 1998.
[120] Walsh, E. J., Surface contour radar directional wave spectra measurements during Lewex, Directional Ocean Wave Spectra, 1991, pp. 86-90.
[121] Walsh, E. J., D. W. Hancock, D. E. Hines, et al., Directional wave spectra measured with the surface contour radar, Journal of Physical Oceanography, vol. 15, no. 5, pp. 566-592, 1985.
[122] Wentz, F. J., and D. K. Smith, A model function for the ocean-normalized radar cross section at 14 GHz derived from NSCAT observations, Journal of Geophysical Research-Oceans, vol. 104, no. C5, pp. 11499-11514, 1999.
[123] Wright, C., E. Walsh, D. Vandemark, et al., Hurricane directional wave spectrum spatial variation in the open ocean, Journal of Physical Oceanography, vol. 31, no. 8, pp. 2472-2488, 2001.
[124] Wright, J. W., Backscattering from capillary waves with application to sea clutter, IEEE Transactions on Antennas and Propagation, vol. Ap14, no. 6,pp. 749-754, 1966.
[125] Yueh, S. H., R. West, F. K. Li, et al., Dual-polarized Ku-band backscatter signatures of hurricane ocean winds, IEEE Transactions on Geoscience and Remote Sensing, vol. 38, no. 1, pp. 73-88, 2000.
[126] Zapevalov, A. S., Bragg scattering of centimeter electromagnetic radiation from the sea surface: The effect of waves longer than Bragg components, Izvestiya Atmospheric and Oceanic Physics, vol. 45, no. 2, pp. 253-261, 2009.
[127] Zhang, B. A., W. Perrie, and Y. H. He, Remote sensing of ocean waves by along-track interferometric synthetic aperture radar, Journal of Geophysical Research-Oceans, vol. 114, 2009.
[128] Zieger, S., J. Vinoth, and I. R. Young, Joint calibration of multiplatform altimeter measurements of wind speed and wave height over the past 20 years, Journal of Atmospheric and Oceanic Technology, vol. 26, no. 12, pp. 2549-2564, 2009.