Long-wavelength Discrepancies Between the Australian Gravity Field and EIGEN-2 CHAMP Data

Long-wavelength differences (in the ~1,100 km to ~6,500 km waveband) are evident between Australian free-air gravity anomalies and those implied by EIGEN-2 to degree 32, which is derived purely from CHAMP data. They reach ~11 mGal for the Australian land gravity anomalies and over ~15 mGal for the [...

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Main Author: Featherstone, Will
Other Authors: Fernando Sanso
Format: Conference Paper
Published: Springer 2005
Subjects:
Online Access:http://hdl.handle.net/20.500.11937/4678
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author Featherstone, Will
author2 Fernando Sanso
author_facet Fernando Sanso
Featherstone, Will
author_sort Featherstone, Will
building Curtin Institutional Repository
collection Online Access
description Long-wavelength differences (in the ~1,100 km to ~6,500 km waveband) are evident between Australian free-air gravity anomalies and those implied by EIGEN-2 to degree 32, which is derived purely from CHAMP data. They reach ~11 mGal for the Australian land gravity anomalies and over ~15 mGal for the [unadjusted] ship-track grav-ity anomalies. These long-wavelength differences are used to quantify the effect on the gravimetric geoid model. Using an unmodified Stokes kernel and no limit on the cap radius (i.e., all terrestrial gravity in the region), the resulting effect on the geoid is between -0.72m and 0.13m, though the large negative value is attributed to a lack of gravity data to the north of Australia. Using a modified Stokes kernel and a one-degree cap radius as a high-pass filter, the resulting effect on the geoid is between -0.28m and 0.10m. Applying the latter and EIGEN-2 to degree 32 as corrections to AUS-Geoid98 yields a small, but insignificant, improvement in the fit to nation-wide GPS-levelling data.
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spelling curtin-20.500.11937-46782017-10-02T02:27:28Z Long-wavelength Discrepancies Between the Australian Gravity Field and EIGEN-2 CHAMP Data Featherstone, Will Fernando Sanso long-wavelength gravity anomaly errors CHAMP geoid dedicated satellite gravimetry Long-wavelength differences (in the ~1,100 km to ~6,500 km waveband) are evident between Australian free-air gravity anomalies and those implied by EIGEN-2 to degree 32, which is derived purely from CHAMP data. They reach ~11 mGal for the Australian land gravity anomalies and over ~15 mGal for the [unadjusted] ship-track grav-ity anomalies. These long-wavelength differences are used to quantify the effect on the gravimetric geoid model. Using an unmodified Stokes kernel and no limit on the cap radius (i.e., all terrestrial gravity in the region), the resulting effect on the geoid is between -0.72m and 0.13m, though the large negative value is attributed to a lack of gravity data to the north of Australia. Using a modified Stokes kernel and a one-degree cap radius as a high-pass filter, the resulting effect on the geoid is between -0.28m and 0.10m. Applying the latter and EIGEN-2 to degree 32 as corrections to AUS-Geoid98 yields a small, but insignificant, improvement in the fit to nation-wide GPS-levelling data. 2005 Conference Paper http://hdl.handle.net/20.500.11937/4678 Springer restricted
spellingShingle long-wavelength gravity anomaly errors
CHAMP
geoid
dedicated satellite gravimetry
Featherstone, Will
Long-wavelength Discrepancies Between the Australian Gravity Field and EIGEN-2 CHAMP Data
title Long-wavelength Discrepancies Between the Australian Gravity Field and EIGEN-2 CHAMP Data
title_full Long-wavelength Discrepancies Between the Australian Gravity Field and EIGEN-2 CHAMP Data
title_fullStr Long-wavelength Discrepancies Between the Australian Gravity Field and EIGEN-2 CHAMP Data
title_full_unstemmed Long-wavelength Discrepancies Between the Australian Gravity Field and EIGEN-2 CHAMP Data
title_short Long-wavelength Discrepancies Between the Australian Gravity Field and EIGEN-2 CHAMP Data
title_sort long-wavelength discrepancies between the australian gravity field and eigen-2 champ data
topic long-wavelength gravity anomaly errors
CHAMP
geoid
dedicated satellite gravimetry
url http://hdl.handle.net/20.500.11937/4678