Documentation for subroutine REDUC3, an algorithm for the linear filtering of gridded magnetic data
Open-File Report
77-784
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Abstract
Subroutine REDUC3 transforms a total field anomaly h1(x,y) , measured on a horizontal and rectangular grid, into a new anomaly h2(x,y). This new anomaly is produced by the same source as h1(x,y) , but (1) is observed at a different elevation, (2) has a source with a different direction of magnetization, and/or (3) has a different direction of residual field. Case 1 is tantamount to upward or downward continuation. Cases 2 and 3 are 'reduction to the pole', if the new inclinations of both the magnetization and regional field are 90 degrees. REDUC3 is a filtering operation applied in the wave-number domain. It first Fourier transforms h1(x,y) , multiplies by the appropriate filter, and inverse Fourier transforms the result to obtain h2(x,y). No assumptions are required about the shape of the source or how the intensity of magnetization varies within it.
Suggested Citation
Blakely, R.J., 1977, Documentation for subroutine REDUC3, an algorithm for the linear filtering of gridded magnetic data: U.S. Geological Survey Open-File Report 77-784, 14, [12] leaves :ill. ;27 cm.; (25 p. - PGS), https://doi.org/10.3133/ofr77784.
ISSN: 2331-1258 (online)
| Publication type | Report |
|---|---|
| Publication Subtype | USGS Numbered Series |
| Title | Documentation for subroutine REDUC3, an algorithm for the linear filtering of gridded magnetic data |
| Series title | Open-File Report |
| Series number | 77-784 |
| DOI | 10.3133/ofr77784 |
| Year Published | 1977 |
| Language | ENGLISH |
| Publisher | U.S. Geological Survey, |
| Description | 14, [12] leaves :ill. ;27 cm.; (25 p. - PGS) |