geoscience.net logo
+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

An empirical approach to inversion of an unconventional helicopter electromagnetic dataset


, : An empirical approach to inversion of an unconventional helicopter electromagnetic dataset. Journal of Applied Geophysics 53(1): 49-61

A helicopter electromagnetic (HEM) survey acquired at the U.S. Idaho National Engineering and Environmental Laboratory (INEEL) used a modification of a traditional mining airborne method flown at low levels for detailed characterization of shallow waste sites. The low sensor height, used to increase resolution, invalidates standard assumptions used in processing HEM data. Although the survey design strategy was sound, traditional interpretation techniques, routinely used in industry, proved ineffective. Processed data and apparent resistivity maps were severely distorted, and hence unusable, due to low flight height effects, high magnetic permeability of the basalt host, and the conductive, three-dimensional nature of the waste site targets. To accommodate these interpretation challenges, we modified a one-dimensional inversion routine to include a linear term in the objective function that allows for the magnetic and three-dimensional electromagnetic responses in the in-phase data. Although somewhat ad hoc, the use of this term in the inverse routine, referred to as the shift factor, was successful in defining the waste sites and reducing noise due to the low flight height and magnetic characteristics of the host rock. Many inversion scenarios were applied to the data and careful analysis was necessary to determine the parameters appropriate for interpretation, hence the approach was empirical. Data from three areas were processed with this scheme to highlight different interpretational aspects of the method. Wastes sites were delineated with the shift terms in two of the areas, allowing for separation of the anthropomorphic targets from the natural one-dimensional host. In the third area, the estimated resistivity and the shift factor were used for geological mapping. The high magnetic content of the native soil enabled the mapping of disturbed soil with the shift term.

US$19.90

DOI: 10.1016/s0926-9851(03)00011-9


Other references

Kummerova M.; Zatezalo S.; Stankovic Z.S., 1989: Acid phosphatase activity of three wheat cultivars depending on phosphate nutrition. Acid phosphatase activity was measured in dry grain, water imbibed grain, root and above ground plant tissues of 10, 17, 24 and 28 days-old plants of three wheat cultivars (Triticum aestivum L., cvs Zitnica, Jugoslavija and Novosadska rana 2) grow...

Wolman, S.R.; Craven, M.L.; Grill, S.P.; Domin, B.A.; Cheng, Y.C., 1983: Quantitative correlation of homogeneously stained regions on chromosome 10 with dihydrofolate reductase enzyme in human cells. Gene amplification may be visualized within a chromosome as a homogeneously stained region (HSR) and HSRs have rarely been reported in human tumor cells with identification of the amplified gene. A parental line and seven clones derived from KB ce...

Saini; Law; Pudney; Garg; Menovsky; Franse, 1995: Evidence of redistribution of the itinerant holes below Tc in Ba2Sr2CaCu2O8 superconductors: A polarized x-ray-absorption study. Physical Review. B, Condensed Matter 52(9): 6219-6222

McGuinness, M.C.; Zhang, H.P.; Smith, K.D., 2001: Evaluation of pharmacological induction of fatty acid beta-oxidation in X-linked adrenoleukodystrophy. X-linked adrenoleukodystrophy (X-ALD) is an inherited neurometabolic disorder associated with elevated levels of saturated unbranched very-long-chain fatty acids (VLCFA; C > 22:0) in plasma and tissues, and reduced VLCFA beta-oxidation in fibro...

Arai, K.; Iiai, T.; Nakayama, M.; Hasegawa, K.; Sato, K.; Ohtsuka, K.; Watanabe, H.; Hanyu, T.; Takahashi, H.E.; Abo, T., 1995: Adhesion molecules on intermediate TCR cells. I. Unique expression of adhesion molecules, CD44+ L-selectin-, on intermediate TCR cells in the liver and the modulation of their adhesion by hyaluronic acid. In addition to thymus-derived T cells, it was demonstrated recently that extrathymically differentiated T cells exist in the liver and other immune organs of mice. Since such extrathymic T cells have T-cell receptors (TCR) of intermediate intensit...

Schubert, K.D.; Schubert-Lehnhardt, V., 1991: Physician's practice is concrete philosophy. Zeitschrift für Arztliche Fortbildung 85(18): 889-892

Gillespie, A.M.; Lidbury, E.A.; Tidy, J.A.; Hancock, B.W., 2004: The clinical presentation, treatment, and outcome of patients diagnosed with possible ectopic molar gestation. The objective of this study was to determine the clinical presentation, treatment, and outcome of patients diagnosed with possible ectopic molar gestation registered with the Trophoblastic Disease Screening and Treatment Centre, Weston Park Hospit...

Sanchez-Villagra, M., R.; Brinkmann, W.; Lozsan, R., 2008: The Paleozoic and Mesozoic vertebrate record of Venezuela An overview, summary of previous discoveries and report of a mosasaur from the La Luna Formation Cretaceous. Most reports of Paleozoic and Mesozoic vertebrates from Venezuela are anecdotical, with few detailed descriptions of mostly 'fish' groups. Synapsids (e.g., mammals) are totally unknown, and dinosaurs are only reported from the La Quinta...

Stevens, GR., 1984: Late Jurassic belemnites from northern Great Barrier Island. New Zealand Geological Survey Record, 41-46 No. 3

Briggs, L.E.; Kakarla, J.; Wessels, A., 2012: The pathogenesis of atrial and atrioventricular septal defects with special emphasis on the role of the dorsal mesenchymal protrusion. Partitioning of the four-chambered heart requires the proper formation, interaction and fusion of several mesenchymal tissues derived from different precursor populations that together form the atrioventricular mesenchymal complex. This includes t...