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重力辅助惯性导航是真正的无源导航,它已成为21世纪无源导航定位技术的主要研究方向之一.本文在进行了一般性的尺度概念及多尺度系统理论概述之后,结合重力场的固有特性,分别从重力场的模型尺度特性、空间尺度特性以及时间尺度特性详细介绍了地球重力场固有的多尺度特性.另外,根据重力辅助惯性导航系统中重力场数据的作用,从利用重力场实... 相似文献
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低轨重力卫星轨道的精确确定是获得精密地球重力场模型的前提, 而精密重力场模型又是获得高精度定轨结果的保证.本文简述了利用卫星重力方法恢复地球重力场及简化动力学方法确定低轨卫星轨道的数学模型,并简单分析和比较现有的几种重力场模型.用CHAMP实测数据,结合现有的重力场模型,系统分析、研究了不同阶次、不同重力场模型对低轨卫星定轨精度的影响;研究了不同间隔的随机速度脉冲在简化动力学方法中对模型误差的吸收、调节作用.计算结果表明,在定轨中,选择合理阶数的、较精确的重力场模型及合理间隔的随机脉冲参数,不但可以提高计算效率,更能提高定轨精度. 相似文献
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利用2011年8月11日新疆伽师MS5.8地震前喀什—伽师流动重力网2009年4月至2011年7月的重力复测数据,绘制区域重力场差分和累计动态变化图像。分析表明:(1)地震发生在断裂带重力变化正、负异常密集区的零等值线附近和重力场的反向恢复变化过程中;地震发生前一年出现"闭锁"的重力变化特征;(2)区域重力场差分变化反映出震前伽师—西克尔地区地壳物质运动信息;区域重力场的"平静—活跃"过程,反映出伽师—西克尔区域重力场短期局部构造运动;区域重力场累计动态变化反映出地壳运动的背景特征;(3)地震震前重力变化等值线平行于断层分布,临震时重力变化等值线近垂直于断层,是一个显著的重力特征。 相似文献
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月球重力场制约着近月外空间物体的运动,同时环月飞行器的运动也反映了月球重力场的作用. 本文结合我国嫦娥一号探月工程,探讨了利用月球卫星的地面跟踪资料,求定月球重力场的基本理论和方法,分析了环月卫星的轨道高度、地面跟踪采样时间间隔和跟踪精度等对求定月球重力场的影响. 若单独利用我国嫦娥一号探月工程的地面跟踪数据,恢复30阶次左右的月球重力场模型是一个比较实际的目标. 地面跟踪最好能以75s的时间间隔进行采样,数据连续提供时间应不少于30个昼夜,月球卫星星下点的月面轨迹间距不大于110km. 相似文献
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利用GRACE卫星重力场模型和地表流动重力观测资料,计算2008年汶川MS 8.0地震发生前6年的重力变化,对卫星和流动重力段差结果与卫星重力反映的重力场动态变化特征进行研究,结果表明:①GRACE卫星重力段差受滤波半径影响显著,与地表流动重力观测结果相比,在重力变化数值上差异较大,在变化率上较为一致;②在汶川地震孕育阶段,川滇地区重力等值线呈“增大—减速增大—减小”的特征,震前2年形成近似垂直于龙门山断裂带的重力变化梯度带。 相似文献
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The inversion of density structure by graphic processing unit (GPU) and identification of igneous rocks in Xisha area
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Organic reefs, the targets of deep-water petroleum exploration, developed widely in Xisha area. However, there are concealed igneous rocks undersea, to which organic rocks have nearly equal wave impedance. So the igneous rocks have become interference for future exploration by having similar seismic reflection characteristics. Yet, the density and magnetism of organic reefs are very different from igneous rocks. It has obvious advantages to identify organic reefs and igneous rocks by gravity and magnetic data. At first, frequency decomposition was applied to the free-air gravity anomaly in Xisha area to obtain the 2D subdivision of the gravity anomaly and magnetic anomaly in the vertical direction. Thus, the distribution of igneous rocks in the horizontal direction can be acquired according to high-frequency field, low-frequency field, and its physical properties. Then, 3D forward modeling of gravitational field was carried out to establish the density model of this area by reference to physical properties of rocks based on former researches. Furthermore, 3D inversion of gravity anomaly by genetic algorithm method of the graphic processing unit (GPU) parallel processing in Xisha target area was applied, and 3D density structure of this area was obtained. By this way, we can confine the igneous rocks to the certain depth according to the density of the igneous rocks. The frequency decomposition and 3D inversion of gravity anomaly by genetic algorithm method of the GPU parallel processing proved to be a useful method for recognizing igneous rocks to its 3D geological position. So organic reefs and igneous rocks can be identified, which provide a prescient information for further exploration. 相似文献
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The inversion of density structure by graphic processing unit (GPU) and identification of igneous rocks in Xisha area 总被引:1,自引:0,他引:1
Organic reefs, the targets of deep-water petroleum exploration, developed widely in Xisha area. However, there are concealed igneous rocks undersea, to which organic rocks have nearly equal wave impedance. So the igneous rocks have become interference for future exploration by having similar seismic reflection characteristics. Yet, the density and magnetism of organic reefs are very different from igneous rocks. It has obvious advantages to identify organic reefs and igneous rocks by gravity and magnetic data. At first, frequency decomposition was applied to the free-air gravity anomaly in Xisha area to obtain the 2D subdivision of the gravity anomaly and magnetic anomaly in the vertical direction. Thus, the distribution of igneous rocks in the horizontal direction can be acquired according to high-frequency field, low-frequency field, and its physical properties. Then, 3D forward modeling of gravitational field was carried out to establish the density model of this area by reference to physical properties of rocks based on former researches. Furthermore, 3D inversion of gravity anomaly by genetic algorithm method of the graphic processing unit(GPU) parallel processing in Xisha target area was applied, and 3D density structure of this area was obtained. By this way, we can confine the igneous rocks to the certain depth according to the density of the igneous rocks. The frequency decomposition and 3D inversion of gravity anomaly by genetic algorithm method of the GPU parallel processing proved to be a useful method for recognizing igneous rocks to its 3D geological position. So organic reefs and igneous rocks can be identified, which provide a prescient information for further exploration. 相似文献
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Summary The effect of an additional homogeneous magnetic field with an intensity of 0–4.5 Oe on the Worden quartz gravity meter No. 961 and on Sharpe quartz gravity meters Nos 173 and 174 was tested. Whereas no effect was observed with the Worden gravity meter, the magnetic field had a measurable effect on both the Sharpe gravity meters. The largest deviation of the reading beam is caused by the horizontal component of the magnetic field which acts in the plane of oscillation of the gravity-meter arm. The Sharpe gravity meter No. 173 is considerably sensitive; a field of 0.2 Oe intensity, corresponding to the magnitude of the horizontal component of the geomagnetic field in mid-latitudes, causes an error in the measurement of gravity of as much as 0.08 mGal. With a view to the different behaviours of the individual quartz gravity meters of the same type in a magnetic field, it should prove expedient to carry out check measurements with all gravity meters and, with regard to the sensitivity of the gravity meter to the magnetic field and the required accuracy of the gravity determination, take into account this perturbing factor in field measurements, as well as laboratory tests of gravity meters. 相似文献
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高精度金星重力场的获取,是金星探测的重要内容.本文利用最新的金星地形和重力模型,通过高通滤波后的残差地形(RTM)并在考虑均衡改正的情况下改进了重力的短波成分,最终提出了一个新的金星重力模型VGM2013,该模型赤道分辨率达10 km量级,大大高于现有的金星重力场模型,最终结果是金星表面重力加速度和重力扰动.研究中同时发现金星在Airy-Heiskanen均衡模型下的全球最优补偿深度为30 km,金星地壳的密度可能小于当前认为的2700~2900 kg·m-3.VGM2013模型的结果可为将来的金星探测器定轨和着陆导航提供参考,作为重力计算的先验模型.但由于该模型没有包含短波重力观测信息,不建议直接用于更小尺度的地质和地球物理解释. 相似文献
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地球重力学是研究重力场时空分布及其物理机制的一门学科.地球重力场的空间分布通常可用于三个方面:一是空间科学和大地测量学,主要是利用地表的重力观测对在其上测得的几何量加以归算,以及给出重力场的高空赋值以修正卫星和近地飞行器的轨道;二是反演地球内部结构,主要是三维密度的不均匀分布,并对诸如地慢对流等作约束;三是勘探在时间变化方面,最主要影响来自固体潮,当然还有许多内部力源导致动力学效应.本文着重对我国大地重力研究和固体潮研究的进展作一回顾. 相似文献
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利用成都地区1996~2008年绝对重力和相对重力观测资料获得区域重力场时空动态变化结果,系统分析了龙门山断裂带重力场变化特征及其与汶川8.0级地震的关系.①重力变化与龙门山断裂构造活动存在密切空间联系,重力测量较好地反映了伴随活动断层的物质迁移和构造变形引起的地表重力变化效应.②成都地区重力场动态图像较完整地反映了2008年5月12日汶川8.0级地震孕育、发生过程中出现的流动重力前兆信息.③映秀及北川重力点值时序变化累积量达120×10-8m·s-2,较好地反映了汶川地震前映秀和北川两个极震区附近的重力测点随时间的剧烈波动性上升变化.④汶川地震前,龙门山断裂带东侧的四川盆地相对稳定,而较显著的重力变化发生在龙门山断裂带西侧的川西高原上. 相似文献