A statistical distribution of quad-pol X-band sea clutter time series acquired at a grazing angle
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摘要: 尽管复Wishart分布已被广泛应用于SAR数据统计分析,然而该分布函数却很少被用来研究雷达海面掠散射回波时间序列的统计特征。本文通过分析IPIX雷达海面掠散射回波数据发现:大尺度海浪遮挡区的雷达回波能量很低,主要是雷达系统噪声,如果将该部分低能量回波数据剔除以后,真实海面的IPIX 雷达回波时间序列数据亦满足圆高斯分布,因此,IPIX 雷达海面回波的时间序列数据也必然满足复Wishart分布。在此,我们基于Wishart分布模型分别对全极化IPIX 雷达不同极化通道数据的海面回波时间序列数据进行了统计研究,并推导给出了不同通道数据协方差矩阵元素实部、虚部及相位差等参数的统计分布函数模型。通过与雷达测量数据比计较可见,推导所得理论统计模型与实际测量数据吻合很好。本文所得结论对进一步深入理解掠散射海面雷达回波的统计特征具有一定理论意义。Abstract: Although the complex Wishart distribution has been widely used to analyze the statistic properties of quad-pol SAR spatial data, the applicability of this complex distribution to the time series of sea clutter is rarely discussed. The measured data of the quad-pol X-band marine radar demonstrate that the time series of the sea echoes are also satisfied the circular Gaussian distributions if the low intensity signals, which are mainly dominated by a radar noise, in the shadow regions of the large-scale waves are removed. On the basis of this fact, the probability density functions (PDFs) of the intensity as well as the phase, the real and the imaginary parts of the sea echoes obtained by the marine radar have been derived, and the theoretical models are all expressed in closed forms. In order to validate the theoretical results, the PDFs are compared with the experimental data collected by the McMaster IPIX radar. And the comparisons show that the PDF models are in good agreement with the experimental data.
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Brusch S, Lehner S, Fritz T, et al. 2011. Ship surveillance with TerraSAR-X. IEEE Transactions on Geoscience and Remote Sensing, 49(3): 1092-1103 Chapman R D, Gotwols B L, Sterner R E. 1994. On the statistics of the phase of microwave backscatter from the ocean surface. Journal of Geophysical Research, 99(C8): 16293-16301 Conte E, De Maio A, Galdi C. 2004. Statistical analysis of real clutter at different range resolutions. IEEE Transactions on Aerospace and Electronic Systems, 40(3): 903-918 Conte E, Longo M, Lops M. 1991. Modelling and simulation of non-Rayleigh radar clutter. IEE Proceedings F-Radar and Signal Processing, 138(2): 121-130 Cui Limin, He Yijun, Shen Hui, et al. 2010. Measurements of ocean wave and current field using dual polarized X-band radar. Chinese Journal of Oceanology and Limnology, 28(5): 1021-1028 Farina A, Gini F, Greco M V, et al. 1997. High resolution sea clutter data: statistical analysis of recorded live data. IEE Proceedings-Radar, Sonar and Navigation, 144(3): 121-130 Farina A, Russo A, Studer F A. 1986. Coherent radar detection in log-normal clutter. IEE Proceedings F-Communications, Radar and Signal Processing, 133(1): 39-53 Goodman N R. 1963. Statistical analysis based on a certain multivariate complex Gaussian distribution (an introduction). The Annals of Mathematical Statistics, 34(1): 152-177 Goodman J W. 1985. Statistical Optics. New York: John Wiley & Sons Gradshteyn I S, Ryzhik I M. 2007. Table of Integrals, Series, and Products. 7th ed. London: Academic Greco M, Bordoni F, Gini F. 2004. X-band sea-clutter nonstationarity: influence of long waves. IEEE Journal of Oceanic Engineering, 29(2): 269-283 Hwang P A, Sletten M A, Toporkov J V. 2008. Breaking wave contribution to low grazing angle radar backscatter from the ocean surface. Journal of Geophysical Research, 113(C9): C09017 Johnson J T, Burkholder R J, Toporkov J V, et al. 2009. A numerical study of the retrieval of sea surface height profiles from low grazing angle radar data. IEEE Transactions on Geoscience and Remote Sensing, 47(6): 1641-1650 Kuttikkad S, Chellappa R. 1994. Non-Gaussian CFAR techniques for target detection in high resolution SAR images. In: IEEE International Conference in Image Processing. Vol. 1. Austin, TX: IEEE, 910-914 Lee P H Y, Barter J D, Beach K L, et al. 1995. X-band microwave backscattering from ocean waves. Journal of Geophysical Research, 100(C2): 2591-2611 Lee J S, Hoppel K W, Mango S A, et al. 1994a. Intensity and phase statistics of multilook polarimetric and interferometric SAR imagery. IEEE Transactions on Geoscience and Remote Sensing, 32(5): 1017-1028 Lee J S, Miller A R, Hoppel K W. 1994b. Statistics of phase difference and product magnitude of multi-look processed Gaussian signals. Waves in Random Media, 4(3): 307-319 Posner F L. 2002. Spiky sea clutter at high range resolutions and very low grazing angles. IEEE Transactions on Aerospace and Electronic Systems, 38(1): 58-73 Vachon P W, Campbell J W M, Bjerkelund C A, et al. 1997. Ship detection by the RADARSAT SAR: validation of detection model predictions. Canadian Journal of Remote Sensing, 23(1): 48-59 Wang Yunhua, Li Huimin, Zhang Yanmin, et al. 2015. The measurement of sea surface profile with X-band coherent marine radar. Acta Oceanologica Sinica, 34(9): 65-70 Yang Y, Xiao S P, Wang X S, et al. 2017. Statistical distribution of polarization ratio for radar sea clutter. Radio Science, 52(8): 981-987,, doi: 10.1002/2017RS006371 Zhu Hong, Wang Qingping, Tai Ning, et al. 2017. Statistical analysis of high-resolution coherent monopulse radar sea clutter. International Journal of Antennas and Propagation, 2017: 7471918
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