排序方式： 共有111条查询结果，搜索用时 15 毫秒
41.
联合GOCE卫星轨道和重力梯度数据严密求解重力场的模拟研究 总被引：1，自引：0，他引：1
论述了联合卫星轨道和重力梯度数据严密求解重力场的方法及数据处理方案,研究了GOCE重力场反演中有色噪声的AR去相关滤波、病态法方程的Kaula正则化和观测值最优加权的方差分量估计等关键问题。模拟结果表明:①极空白问题会降低法方程求解的稳定性,导致低次位系数的求解精度较低,而Kaula正则化可有效用于GOCE病态法方程的求解,并得到合理稳定的解;②重力梯度有色噪声会降低GOCE重力场求解的整体精度,特别是对低阶位系数的影响最为明显,而AR去相关滤波法可有效处理有色噪声,但解算结果仍含有低频误差;③方差分量估计可有效确定SST和SGG两类观测值的最优权比,并且有色噪声造成的低频误差经过联合求解后得到了抑制;④利用30d、5s采样的GOCE模拟数据恢复200阶次的重力场模型,其大地水准面和重力异常精度在纬度±83°范围内分别为±3.81cm和±1.056mGal。 相似文献
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卫星测高与卫星重力对洋流的研究 总被引：2，自引：0，他引：2
卫星测高与卫星重力的发展为进一步研究洋流提供了前所未有的机遇。本文从EGM 96 ,GGM0 1与未来的GOCE任务获取的高精度高分辨率海洋大地水准面的角度对洋流的研究方法与可行性进行了分析 相似文献
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卫星重力探测技术的发展 总被引：2，自引：0，他引：2
在地球物理勘探领域中,人造地球卫星的发射为重力测量提供了新的途径。与以往探测重力的手段相比,重力卫星的发射大大改善了人们对地球重力场的认识,随着CHAMP、GRACE和GOCE卫星的发射,将把现有静态中长波部分重力场的精度提高1—2个数量级,并提供长波部分重力场随时间变化的信息。卫星重力学对我国的基础测绘服务和国防建设有着重要的实用价值。 相似文献
44.
扰动重力梯度的非奇异表示 总被引：5，自引：0，他引：5
在局部指北坐标系中用地心球坐标来表示扰动重力梯度张量,当计算点趋近于两极时,由于Legendre函数的一阶和二阶导数以及分母上所含余纬的正弦函数,将导致扰动重力梯度张量的计算出现无穷大。因此,本文引入了Legendre函数的一阶和二阶导数以及 无奇异性的计算公式,并且进一步推导了 无奇异性的计算公式。在将Legendre函数的一阶和二阶导数以及 、 无奇异性的计算公式代入到扰动重力梯度张量各分量的求解中时,又充分考虑了m等于0,1,2以及其它量时的复杂情况,建立了扰动重力梯度张量各分量无奇异性的详细计算模型。通过模拟实验表明,本文所建立的详细计算模型不仅能够完全满足当前卫星重力梯度张量计算的精度要求,而且模型稳定、可靠、易于编程实现。 相似文献
45.
GOCE卫星重力探测任务 总被引：1，自引：0，他引：1
通过分析利用卫星观测技术恢复地球重力场的现状与不足,论述了实施GOCE任务———地球重力场和稳态海洋环流实验的必要性;并阐述了GOCE任务的发展历史及现状、基本特点、组成部分、重力梯度测量原理、数据处理过程、误差特性,以及该任务在固体地球物理学、大地测量学、海洋学、冰河学等地球物理相关科学领域中的应用。 相似文献
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GOCE gradiometer: estimation of biases and scale factors of all six individual accelerometers by precise orbit determination 总被引：3，自引：0，他引：3
P. N. A. M. Visser 《Journal of Geodesy》2009,83(1):69-85
A method has been implemented and tested for estimating bias and scale factor parameters for all six individual accelerometers
that will fly on-board of GOCE and together form the so-called gradiometer. The method is based on inclusion of the individual
accelerometer observations in precise orbit determinations, opposed to the baseline method where so-called common-mode accelerometer
observations are used. The method was tested using simulated data from a detailed GOCE system simulator. It was found that
the observations taken by individual accelerometers need to be corrected for (1) local satellite gravity gradient (SGG), and
(2) rotational terms caused by centrifugal and angular accelerations, due to the fact that they are not located in the satellite’s
center of mass. For these corrections, use is made of a reference gravity field model. In addition, the rotational terms are
derived from on-board star tracker observations. With a perfect a priori gravity field model and with the estimation of not
only accelerometer biases but also accelerometer drifts, scale factors can be determined with an accuracy and stability better
than 0.01 for two of the three axes of each accelerometer, the exception being the axis pointing along the long axis of the
satellite (more or less coinciding with the flight direction) for which the scale factor estimates are unreliable. This axis
coincides with the axis of drag-free control, which results in a small variance of the signal to be calibrated and thus an
inaccurate determination of its scale factor in the presence of relatively large (colored) accelerometer observation errors.
In the presence of gravity field model errors, it was found that still an accuracy and stability of about 0.015 can be obtained
for the accelerometer scale factors by simultaneously estimating empirical accelerations. 相似文献
49.
We have defined new algorithms for the data processing of a satellite geodesy mission with gradiometer (such as the next European
mission GOCE) to extract the information on the gravity field coefficients with a realistic estimate of their accuracy. The
large scale data processing can be managed by a multistage decomposition. First the spacecraft position is determined, i.e.,
a kinematic method is normally used. Second we use a new method to perform the necessary digital calibration of the gradiometer.
Third we use a multiarc approach to separately solve for the global gravity field parameters. Fourth we use an approximate
resonant decomposition, that is we partition in a new way the harmonic coefficients of the gravity field. Thus the normal
system is reduced to blocks of manageable size without neglecting significant correlations. Still the normal system is badly
conditioned because of the polar gaps in the spatial distribution of the data. We have shown that the principal components
of the uncertainty correspond to harmonic anomalies with very small signal in the region where GOCE is flying; these uncertainties
cannot be removed by any data processing method. This allows a complete simulation of the GOCE mission with affordable computer
resources. We show that it is possible to solve for the harmonic coefficients up to degree 200–220 with signal to error ratio
≥1, taking into account systematic measurement errors. Errors in the spacecraft orbit, as expected from state of the art satellite
navigation, do not degrade the solution. Gradiometer calibration is the main problem. By including a systematic error model,
we have shown that the results are sensitive to spurious gradiometer signals at frequencies close to the lower limit of the
measurement band. If these spurious effects grow as the inverse of the frequency, then the actual error is larger than the
formal error only by a factor ≃2, that is the results are not compromised. 相似文献
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