Journal ArticleDOI
Reduction Of Unevenly Spaced Potential Field Data To A Horizontal Plane By Means Of Finite Harmonic Series
TLDR
In this article, a method is developed for reducing to a common level gravity or magnetic anomaly data observed at unevenly spaced stations at various elevations above a reference plane, effected by means of finite harmonic series approximations in which the coefficients are determined by matrix methods and least squares.Abstract:
Conventional reductions of gravity and magnetic data do not lead to values that are effectively on the same horizontal plane, although it is common practice to regard them so. In regions of high topographic relief, failure to take into account local differences in vertical gradients can result in appreciable error. In this study a method is developed for reducing to a common level gravity or magnetic anomaly data observed at unevenly spaced stations at various elevations above a reference plane. The reduction is effected by means of finite harmonic series approximations in which the coefficients are determined by matrix methods and least squares. Traditional Fourier methods are not applicable because uneven station spacing and relative vertical displacement of stations preclude the use of the orthogonality properties of the trigonometric functions. The number of terms required to represent the data adequately is discussed in terms of “cutoff” wavenumbers empirically determined from residual variance estim...read more
Citations
More filters
Journal ArticleDOI
Interpretation Theory in Applied Geophysics Grant (McGraw-Hill, 140s.)
TL;DR: Interpretation theory in applied geophysics: Grant, F S as mentioned in this paper, Unknown Binding, January 1, 1965 5.0 out of 5 stars 1 rating. Read it now.
Journal ArticleDOI
The terrain effect on terrestrial heat flow
TL;DR: In this article, a new approach to the topographic correction for terrestrial heat flow measurements is presented, which features calculation of a Fourier series fit to the surface temperature-surface elevation data where the surface temperatures are based on a model that includes surface temperature variations due to microclimate variations.
Book ChapterDOI
Continental Heat-Flow Density
TL;DR: In this paper, the authors consider the thermal regime of the Earth to be quasi-steady state over times of the order of the thermal time constant for the crust, that is a few hundred thousand to a few million years.
Journal ArticleDOI
Standardization in gravity reduction
TL;DR: In this paper, a field example from British Columbia illustrates both the variations in vertical gravity gradients which can be encountered and the conclusion that the classical approach to data reduction is practically always suitable to account for the observed effects.
Journal ArticleDOI
Gravity anomaly separation by wiener filtering
R. S. Pawlowski,R. O. Hansen +1 more
TL;DR: In this article, a gravity anomaly separation method based on frequency-domain Wiener filtering is proposed. But the method is not suitable for terrestrial applications, as it requires a more objective estimate of the signal power spectrum required for defining the transfer function of the filter.
References
More filters
Journal ArticleDOI
Interpretation Theory in Applied Geophysics Grant (McGraw-Hill, 140s.)
TL;DR: Interpretation theory in applied geophysics: Grant, F S as mentioned in this paper, Unknown Binding, January 1, 1965 5.0 out of 5 stars 1 rating. Read it now.
Journal ArticleDOI
The equivalent source technique
TL;DR: In this article, the authors synthesize an equivalent source of discrete point masses on a plane of arbitrary depth below the surface by keeping the depth of the plane within certain limits relative to the station spacing, and then the synthesized field closely approximates the true gravity field in the region close to and above the terrain.
Journal ArticleDOI
Two‐dimensional harmonic analysis as a tool for magnetic interpretation
TL;DR: In this paper, a double Fourier series expansion of the anomalous total magnetic field was used to calculate the magnetic pole and its second derivative, free from the effect of the inclination of the earth's main geomagnetic field and the polarization vector at all magnetic latitudes and directions of polarization.
Journal ArticleDOI
Investigation of the vertical gradient of gravity
TL;DR: The vertical gradient of gravity was first calculated by Helmert about 1910 as mentioned in this paper, and the current value of −0.3086 mg (milligal) per meter has been established by several observers who noted the change in weight of a mass with height.
Related Papers (5)
Reduction of magnetic and gravity data on an arbitrary surface acquired in a region of high topographic relief
B. K. Bhattacharyya,K. C. Chan +1 more