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dc.contributor.authorFeatherstone, Will
dc.contributor.authorKirby, Jonathan
dc.identifier.citationFeatherstone, W. E. and Kirby, J. F. 2000. The reduction of aliasing in gravity anomalies and geoid heights using digital terrain data. Geophysical Journal International 141: pp. 204-212.

Observations of gravity can be aliased by virtue of the logistics involved in collecting these data in the field. For instance, gravity measurements are often made in more accessible lowland areas where there are roads and tracks, thus omitting areas of higher relief in between. The gravimetric determination of the geoid requires mean terrain-corrected free-air anomalies; however, anomalies based only on the observations in lowland regions are not necessarily representative of the true mean value over the topography. A five-stage approach is taken that uses a digital elevation model, which provides a more accurate representation of the topography than the gravity observation elevations, to reduce the unrepresentative sampling in the gravity observations. When using this approach with the Australian digital elevation model, the terrain-corrected free-air anomalies generated from the Australian gravity data base change by between 77.075 and -84.335 mgal (-0.193 mgal mean and 2.687 mgal standard deviation). Subsequent gravimetric geoid computations are used to illustrate the effect of aliasing in the Australian gravity data upon the geoid. The difference between 'aliased' and 'non-aliased' gravimetric geoid solutions varies by between 0.732 and -1.816 m (-0.058 m mean and 0.122 m standard deviation). Based on these conceptual arguments and numerical results, it is recommended that supplementary digital elevation information be included during the estimation of mean gravity anomalies prior to the computation of a gravimetric geoid model.

dc.publisherBlackwell Publishing Ltd
dc.subjectdigital terrain models
dc.titleThe reduction of aliasing in gravity anomalies and geoid heights using digital terrain data
dc.typeJournal Article
dcterms.source.titleGeophysical Journal International

Copyright © 2000 John Wiley & Sons, Ltd.

curtin.accessStatusOpen access via publisher
curtin.facultyDepartment of Spatial Sciences
curtin.facultyFaculty of Science and Engineering
curtin.facultyWA School of Mines

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