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11.
含油气性物化探信息双子波群灰色关联滤波提取 总被引:1,自引:0,他引:1
构建了一个考虑两个子波群,增加信息约束条件对研究区物化探信息进行滤波的新模型-双子波关联滤波模型。对模型的分析研究与应用表明,新模型对物化探油气性信息的识别、提取具有更强的能力。 相似文献
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我国9大气候区降水特性及其物理成因的研究Ⅰ——基本特性分析 总被引:2,自引:2,他引:2
首先利用旱涝Z指数对全国9大气候区的旱涝进行了评定,并给出我国9大气候区旱涝Z指数的分布图。分析结果表明,1950年代我国除新疆地区处于偏早期外,其它几个区都处于多雨量期,1960年代由多雨向少雨转变的时期,1970年代——1980年代中期我国大部分地区处于雨量偏少期;1990年之后我国各个区的雨量都有所增加。此外,还应用Morlet小波变化对我国9大气候区降水的旱涝周期变化、旱涝分型及变化趋势进行了分析。研究结果表明:在16年、32年层次变化上,各气候区在不同时间段上,8年层次上降水的变化出现了一定的规律:东北、华北在1980年之后存在1年位相差;而长江中下游、江南及华南三者之间在1951~1970年时段上依次有着2年的位相差;长江中下游、内蒙及新疆之间依次存在着3年位相差。 相似文献
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The purpose of GPS-satellite-to-satellite tracking (GPS-SST) is to determine the gravitational potential at the earth's surface from measured ranges (geometrical distances) between a low-flying satellite and the high-flying satellites of the Global Positioning System (GPS). In this paper, GPS-satellite-to-satellite tracking is reformulated as the problem of determining the gravitational potential of the earth from given gradients at satellite altitude. The uniqueness and stability of the solution are investigated. The essential tool is to split the gradient field into a normal part (i.e. the first-order radial derivative) and a tangential part (i.e. the surface gradient). Uniqueness is proved for polar, circular orbits corresponding to both types of data (first radial derivative and/or surface gradient). In both cases gravity recovery based on satellite-to-satellite tracking turns out to be an exponentially ill-posed problem. Regularization in terms of spherical wavelets is proposed as an appropriate solution method, based on the knowledge of the singular system. Finally, the extension of this method is generalized to a nonspherical earth and a non-spherical orbital surface, based on combined terrestrial and satellite data. 相似文献
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应用小波伽略金方法,对Maxwell方程进行离散化,导出了DB2-MRTD算法的探地雷达3D差分公式、数值稳定性条件.在此基础上,开发了探地雷达MRTD(multi-resolution time domain)法正演模拟程序,该程序极大地提高了运算速度,改善了三维探地雷达正演方法,并利用该自制程序,对三角形金属体模型进行了正演模拟,得到了其相应的正演合成三维剖视图及切片图,通过对这些模拟结果进行分析,可以加深对三维雷达反射特征的认识,提高探地雷达探测的可靠性、准确度,同时也说明时域多分辨率法在探地雷达三维正演模拟中的有效性. 相似文献
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Radial velocity anomalies in the lower mantle that give rise to triplications in the travel-time curve for short-periodP waves will produce arrivals havingdT/d values that differe by roughly 0.2–0.5 s/deg. The first two arrivals associated with such triplications will be separated by less than one second over a distance range of 4°–10° they may not, therefore, be separable visually on single seismograms, so that their presence can only be inferred from some measurable property that depends on their mutual interference. If there are lateral variations in the regions of anomalous velocity gradients, the interfering signals will also have different azimuths of arrival. Using two synthetic wavelets we have investigated the effect of interference on bothdT/d and azimuth measurements at the Yellowknife Array. We found that if the interfering pulses have a dominant frequencyv, there is a range of time separations (0.30/v0.55/v) over which the measureddT/d and azimuth values may fluctuate by much more than the differences indT/d and azimuth between the interfering signals. We have evaluated the following empirically defined functions for three different primary signals, and for three different relative amplitudes of the interfering signals:f
(t), the drift function, which expresses how the measured slownesses,p, and azimuths, , differ from the slownesses and azimuths of the primary wavelets; f(), the range function, which describes the behaviour of the upper and lower bounds ofp and as a function of the difference in arrival times of the signals, andf
, studied the properties of these functions, and have outlined how these properties provide criteria based on the numerical and statistical characteristics of the arrival vectors, and on the waveform of the signal that will enable small radial velocity anomalies to be more clearly delineated.Contribution No. 863 from the Earth Physics Branch. 相似文献
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Feature removal and isolation in potential field data 总被引:1,自引:0,他引:1
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根据栅格数字地图亮度高、低频分量变化大、像素值为整数等特点,提出了一种基于整数小波变换的栅格数字地图水印算法。首先将栅格数字地图进行离散整数小波变换,然后分别将水印嵌入到低频分量和高频细节分量。低频分量部分依据其亮度自适应嵌入周期性扩展水印,细节分量部分根据人类视觉系统特性在感知重要系数中嵌入水印信息。实验表明,该算法对于诸如JPEG压缩、剪裁、锐化、扭曲变形等各种常见的恶意攻击具有良好的鲁棒性。 相似文献