排序方式： 共有29条查询结果，搜索用时 677 毫秒
11.
基于扭矩测量的二维簧片重力梯度仪的设计 总被引：1，自引：0，他引：1
基于扭矩测量原理,设计了一个精度为1E的二维簧片重力梯度仪。它的敏感部分是一个簧片悬挂的二维Z形扭摆,用一个高灵敏度的二维电容微位移传感器来检测此摆的二维扭转情况,进而获得摆周围的重力梯度信息。该二维簧片重力梯度仪具有性能稳定、精度高等优点。 相似文献
12.
13.
14.
15.
16.
重力梯度测量的现状及复兴 总被引：19，自引：3，他引：16
评述重力梯度测量的发展史,介绍重力梯度的各种应用,预测重力梯度测量的前景.由于重力梯度值或重力高次导数具有比重力本身高的分辨率,特别适合于探测或研究局部的小地质体及其细节;由于美国海军秘密重力梯度仪技术的公开,并投入工业应用,以及多种新型重力梯度仪正在加速研究,重力梯度测量在石油、金属矿勘探和小地质体探测以及研究方面必将起更重要的作用. 相似文献
17.
Least-squares collocation may be used for the estimation of spherical harmonic coefficients and their error and error correlations
from GOCE data. Due to the extremely large number of data, this requires the use of the so-called method of Fast Spherical
Collocation (FSC) which requires that data is gridded equidistantly on each parallel and have the same uncorrelated noise
on the parallel. A consequence of this is that error-covariances will be zero except between coefficients of the same signed
order (i.e., the same order and the same coefficient type C–C or S–S). If the data distribution and the characteristics of the data noise are symmetric with respect to the equator, then, within
a given order and coefficient type, the error-covariances amongst coefficients whose degrees are of different parity also
vanish. The deviation from this “ideal” pattern has been studied using data-sets of second order radial derivatives of the
anomalous potential. A total number of points below 17,000 were used having an equi-angular or an equal area distribution
or being associated with points on a realistic GOCE orbit but close to the nodes of a grid. Also the data were considered
having a correlated or an uncorrelated noise and three different signal covariance functions. Grids including data or not
including data in the polar areas were used. Using the functionals associated with the data, error estimates of coefficients
and error-correlations between coefficients were calculated up to a maximal degree and order equal to 90. As expected, for
the data-distributions with no data in the polar areas the error-estimates were found to be larger than when the polar areas
contained data. In all cases it was found that only the error-correlations between coefficients of the same order were significantly
different from zero (up to 88%). Error-correlations were significantly larger when data had been regarded as having non-zero
error-correlations. Also the error-correlations were largest when the covariance function with the largest signal covariance
distance was used. The main finding of this study was that the correlated noise has more pronounced impact on gridded data
than on data distributed on a realistic GOCE orbit. This is useful information for methods using gridded data, such as FSC. 相似文献
18.
19.
Parametric least squares collocation was used in order to study the detection of systematic errors of satellite gradiometer
data. For this purpose, simulated data sets with a priori known systematic errors were produced using ground gravity data
in the very smooth gravity field of the Canadian plains. Experiments carried out at different satellite altitudes showed that
the recovery of bias parameters from the gradiometer “measurements” is possible with high accuracy, especially in the case
of crossing tracks. The mean value of the differences (original minus estimated bias parameters) was relatively large compared
to the standard deviation of the corresponding second-order derivative component at the corresponding height. This mean value
almost vanished when gravity data at ground level were combined with the second-order derivative data set at satellite altitude.
In the case of simultaneous estimation of bias and tilt parameters from ∂2
T/∂z
2“measurements”, the recovery of both parameters agreed very well with the collocation error estimation.
Received: 10 October 1996 / Accepted 25 May 1998 相似文献
20.
全张量重力梯度仪器测量数据中包含了大量的白噪声和有色噪声。传统的数字滤波器只能滤除某一频段外的噪声,对于混叠在重力梯度有用信号频段范围内的有色噪声不能很好的对其进行分离。为了同时滤除白噪声和有色噪声,笔者利用卡尔曼滤波器采用增广矩阵法将全张量重力梯度数据中的有色噪声进行估计,在抑制白噪声的同时将有用信号和有色噪声分离,并利用数字滤波器与卡尔曼滤波器的优点,将其结合生了更好的滤波效果,得到了更高质量的梯度信号。通过模型试验验证了本方法对噪声的滤波能力,并满足高精度重力梯度数据处理要求。 相似文献