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琼东南盆地深水中央峡谷地震资料不仅具有噪声多样、多次波发育、大水体特征明显、速度敏感、波场复杂等深水地震资料的一般特征,还具有强烈多次波及绕射多次波掩盖古近系烃源岩及底辟、微裂隙运移通道等信号弱、横向垂向速度变化剧烈、分段多期次重力流沉积需要高分辨率资料、多年度采集拼接难度较大等问题。针对复杂的地质特征和地球物理特征,分析一般深水地震资料处理方法的优缺点,提出基于三维去除地表相关多次波(SRME)和剩余绕射波(RDMA)方法为核心的组合多次波衰减、高精度网格速度层析反演、宽频处理、基于子波一致性的连片匹配拼接、各向异性叠前深度偏移(PSDM)等关键技术,形成了琼东南深水中央峡谷地震资料处理方法。实际资料的处理效果表明,该方法能够有效提升中央峡谷地震资料质量。 相似文献
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针对几何衰减外行波,推导了几何衰减平面波多次透射边界、几何衰减球面波多次透射边界以及2种边界的频域反射系数,与无衰波多次透射边界相比,基于几何衰减波特性的多次透射边界在透射几何衰减外行波时,反射系数最小.通过对有限元分析软件ANSYS进行二次开发,成功地将几何衰减波多次透射边界、无衰波多次透射边界以及粘弹性人工边界嵌入到有限元软件中,由3种人工边界下散射问题的有限元数值算例结果可知:考虑衰减波特性的二阶透射边界计算精度最高. 相似文献
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地震数据去噪在地震资料处理中是必不可少的步骤,随着地震勘探的日益发展与进步,对地震资料的信噪比提出了更高的要求。曲波变换作为新兴的多尺度变换方法,在地震资料去噪中拥有巨大的潜力。提出了一种基于曲波变换的面波去噪方法:首先对经过预处理的含噪信号进行多尺度分解,然后在各尺度下尽可能提取出有效信号的曲波系数,同时去除噪声的曲波系数,最后用曲波逆变换重构出地震信号,从而达到去噪目的。试验结果验证了曲波变换去噪的可行性。 相似文献
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多聚焦叠加是目前已知的最佳零偏移距叠加成像方式。对多聚焦叠加方法做改进,利用得到的波场参数来提高叠前地震资料的质量。利用多聚焦波场参数做部分多聚焦叠加,对菲涅尔带内的多个相邻CMP(共中心点)道集做倾角、曲率等校正后合并为一个道集即多聚焦超道集(部分多聚焦叠加),可以补齐缺失地震道,实现叠前数据规则化,并提高信噪比,从而使得叠前道集中的同相轴尤其是来自深层的反射轴有更好的连续性,有利于识别和追踪。提高质量后的叠前道集可用于后续的速度分析、叠加、偏移等常规处理中,效果好于原始CMP道集。模型和实际地震数据的处理结果验证了该方法的正确性和有效性,该方法在低信噪比地震资料处理中将会有广阔的应用前景。 相似文献
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为研究应力波在管道中的传播特性,了解应力波在管道传播中其能量变化与传播距离之间的关系,并验证压电陶瓷材料应用于应力波管道检测的可行性,以粘贴在管道上的压电陶瓷片作为信号激励器或接收器,通过监测不同位置处压电陶瓷接收器的输出电压,计算出各接收器输出电压的峰值。引入衰减指标这一概念作为应力波因子,并利用小波包能量法计算出应力波衰减指标,分析应力波衰减指标与传播距离之间的关系。研究结果表明,应力波在管道中传播时,距离激励器越远的接收器所接收到的应力波电压峰值越小,应力波能量衰减指标越大,说明随着应力波传播距离的增大,应力波能量不断减小,出现衰减。 相似文献
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Strong, scattered reflections beyond 8 degrees (8degrees) offset are characteristic features of all high-resolution seismic sections from the continents. The reflections identify a low-velocity zone below approximately 100 kilometers depth beneath generally stratified mantle. This zone may be caused by partial melting, globally initiated at equal depth in the continental mantle. Solid state is again attained at the Lehmann discontinuity in cold, stable areas, whereas the zone extends to near the 400-kilometer discontinuity in hot, tectonically active areas. Thus, the depth to the Lehmann discontinuity may be an indicator of the thermal state of the continental mantle. 相似文献
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Powell CA Bollinger GA Chapman MC Sibol MS Johnston AC Wheeler RL 《Science (New York, N.Y.)》1994,264(5159):686-688
Ten years of monitoring microearthquakes with a regional seismic network has revealed the presence of a well-defined, linear zone of seismic activity in eastern Tennessee. This zone produced the second highest release of seismic strain energy in the United States east of the Rocky Mountains during the last decade, when normalized by crustal area. The data indicate that seismicity produced by regional, intraplate stresses is now concentrating near the boundary between relatively strong and weak basement crustal blocks. 相似文献
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Samuël Delefortrie Timothy Saey Jan De Pue Ellen Van De Vijver Philippe De Smedt Marc Van Meirvenne 《Precision Agriculture》2016,17(3):349-364
When regarding evolutions in land-based, motorized sensor data collection it can be generalized that the speed of surveying, sampling rates, digital communications speed and survey resolutions have increased over the last years. Possibilities for accurate positioning have been following pace. However, a spatial offset between sensor and position data can be necessary to avoid interference with the instrument or can be the result of using a sensor array. It can also be due to practical considerations such as mounting possibilities. Unfortunately a severe degradation of positional accuracy is possible when performing corrections for a spatial offset and quantification of the induced error is quite difficult. As a consequence, the actual positional accuracy of sensor measurements is therefore often omitted or unknown, and a correction may be neglected during data processing. In this paper, accounting for a horizontal (spatial) offset is researched by examining the use of several correction methods. To evaluate the degree of loss of positional accuracy and validate several correction procedures, global navigation satellite system (GNSS) data (with real-time kinematic correction) have been simultaneously collected, using a GNSS receiver that was mounted on an all-terrain vehicle and two other receivers that were mounted near the front and end of an elongated sensor sled. The sled was connected to the towing vehicle using a flexible connection. Since the positioning systems’ horizontal accuracies were about 20 mm, it was possible to quantify the horizontal error of the predicted positions for the different correction procedures considered. The best approach for high-resolution surveys, which make use of a connection to a cart or sled that can rotate around a pivot on the towing vehicle, was researched. The strengths and weaknesses of the applied corrections were also evaluated, allowing selection of an appropriate correction for a given survey implementation. 相似文献
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Moho offset across the northern margin of the tibetan plateau 总被引:9,自引:0,他引:9
Anomalous double-pulse teleseismic P-wave arrivals were observed at one station near the northern margin of the Tibetan Plateau. The azimuthal dependence of the waveform distortion and its absence at nearby stations indicated that the distortion was produced by receiver-side crustal heterogeneity. Modeling of the three-component data revealed a 15- to 20-kilometer Moho offset that occurs over a narrow lateral range of less than 5 kilometers. This east-west-striking offset separates the thick Tibetan Plateau crust from the Qaidam Basin crust. Such a sharp crustal thickness change implies a weak Tibetan Plateau crust that thickens vertically in response to penetration by India from the south and to blockage caused by a strong Qaidam Basin crust to the north. 相似文献
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van der Meijde M Marone F Giardini D van der Lee S 《Science (New York, N.Y.)》2003,300(5625):1556-1558
Water in the deep upper mantle can influence the properties of seismic discontinuities in the mantle transition zone. Observations of converted seismic waves provide evidence of a 20- to 35-kilometer-thick discontinuity near a depth of 410 kilometers, most likely explained by as much as 700 parts per million of water by weight. 相似文献
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光谱预处理对近红外光谱无损检测番茄可溶性固形物含量的影响 总被引:1,自引:0,他引:1
为了探索适合近红外光谱无损检测番茄可溶性固形物含量的光谱预处理方法,比较了平均光谱和10种光谱预处理方法对偏最小二乘法建模效果的影响,常数偏移消除预处理后的光谱,所建偏最小二乘法校正模型的预测值和实测值的相关系数为0.954,校正标准差为0.321%,最能代表番茄可溶性固形物含量信息的光谱区为11998.9~5449.8cm-1和4601.3~4246.5cm-1.结果表明常数偏移消除是近红外光谱无损检测番茄可溶性同形物含量的有效预处理方法. 相似文献
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Repeating seismic events in China 总被引:7,自引:0,他引:7
About 10% of seismic events in and near China from 1985 to 2000 were repeating events not more than about 1 kilometer from each other. We cross-correlated seismograms from approximately 14,000 earthquakes and explosions and measured relative arrival times to approximately 0.01 second, enabling lateral location precision of about 100 to 300 meters. Such precision is important for seismic hazard studies, earthquake physics, and nuclear test ban verification. Recognition and measurement of repeating signals in archived data and the resulting improvement in location specificity quantifies the inaccuracy of current procedures for picking onset times and locating events. 相似文献
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讨论了一种非常规的反演方法,通过建立地震属性与测井曲线之间的统计模型——多元线性回归模型,预测各种储层参数。在模型建立过程中,用交互有效性来检验模型的可信度,并且采用逐步回归的方法来确定属性选取的优先权。应用该方法,理论上可以预测储层物性参数的分布。 相似文献
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The analysis of line-of-sight residual accelerations from Lunar Orbiters 3 and 5 does not show any evidence for large mascons near the lunar limbs. Although unfavorable geometry reduces the acceleration effect due to any mascon near the limb, simulations show that large masses at Mare Orientale and Mare Marginis would produce substantial accelerations, in complete disagreement with the actual Doppler tracking data obtained from a Lunar Orbiter experiment. 相似文献
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Kieffer HH Chase SC Martin TZ Miner ED Palluconi FD 《Science (New York, N.Y.)》1976,194(4271):1341-1344
Broadband thermal and reflectance observations of the martian north polar region in late summer yield temperatures for the residual polar cap near 205 K with albedos near 43 percent. The residual cap and several outlying smaller deposits are water ice with included dirt; there is no evidence for any permanent carbon dioxide polar cap. 相似文献