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Geology topics

Walter L. Anderson

Publications and source records attributed to Walter L. Anderson.

At least 19 recordsLinked to original sources
USGS1978

Interpretation of electromagnetic extra-low-frequency soundings in the Randsburg, California, Known Geothermal Resource Area

An electromagnetic (EM) controlled source survey was made during the period Nov. 30, 1977, to Dec. 13, 1977, in the Randsburg, California, Known Geothermal Resource Area (KGRA). This report summarizes the observed extra-low-frequency (ELF) data and least squares interpretation using a computer program developed by Anderson (1977). The results are given in tabular form along with observed and calculated amplitude and phase plots. In addition, one vertical electrical sounding (VES) was obtained and a graphical solution is included via a Schlumberger inversion program developed by Zohdy (1973).

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USGS1975

Improved digital filters for evaluating Fourier and Hankel transform integrals

New algorithms are described for evaluating Fourier (cosine, sine) and Hankel (J 0 ,J 1 ) transform integrals by means of digital filters. The filters have been designed with extended lengths so that a variable convolution operation can be applied to a large class of integral transforms having the same system transfer function. A f' lagged-convolution method is also presented to significantly decrease the computation time when computing a series of like-transforms over a parameter set spaced the same as the filters. Accuracy of the new filters is comparable to Gaussian integration, provided moderate parameter ranges and well-behaved kernel functions are used. A collection of Fortran IV subprograms is included for both real and complex functions for each filter type. The algorithms have been successfully used in geophysical applications containing a wide variety of integral transforms

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