| Autor: |
Gavazzi, B., Bertrand, L., Munschy, M., Mercier de Lépinay, J., Diraison, M., Géraud, Y. |
| Předmět: |
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| Zdroj: |
Journal of Geophysical Research. Solid Earth; May2020, Vol. 125 Issue 5, p1-15, 15p |
| Abstrakt: |
Airborne magnetic surveys are common in geosciences. High‐precision surveys are usually performed at a low altitude, draping the topography, using scalar absolute magnetometers and active compensation systems to correct the disturbances generated by the carrier. Another solution is to measure the total magnetic intensity using vector magnetometers, which allows compensation for aircraft fields to be calculated directly, without compensation systems. This study uses data of an industrial airborne survey and of a vector magnetometer survey with a small overlapping area in the Vosges (France) to compare both data sets and shows that both solutions provide results of the same overall precision. This paper also addresses the issue of combining fixed altitude and draped level data sets as well as topographic effect management by proposing an equivalent source interpolator based on a set of simple dipole sources. A synthetic case shows that the equivalent source interpolator allows to compute grids of the magnetic anomaly as well as potential field transforms from a draped data set with an error level a few orders of magnitude lower than could be obtained with minimum curvature, a classically applied interpolator. The interpolator is also tested on a case study in the Vosges massif of which geological interpretation is presented in Bertrand et al. (2020, https://doi.org/10.1029/2019JB017688). The results confirm the observations made on the synthetic case and show that the equivalent source interpolator is more tolerant to navigation errors (altitude) than minimum curvature and allows more rigorous computation of potential field transforms of draped data sets. Key Points: Total magnetic intensity surveys conducted with vector magnetometer systems offer the same data quality as with industrial scalar systemsThe use of potential field transforms on data sets that drape the topography can lead to significant errorsAn equivalent source interpolator allows merging different magnetic surveys and computes potential field transforms of draping data sets [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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