Sökning: id:"swepub:oai:DiVA.org:kth-61381" >
Generation of verti...
Generation of vertical–horizontal and horizontal–horizontal gravity gradients using stochastically modified integral estimators
-
- Eshagh, Mehdi (författare)
- KTH,Geodesi och geoinformatik,Royal Institute of Technology (KTH), Division of Geodesy and Geoinformatics,
-
- Romeshkani, Mohsen, 1984- (författare)
- Department of Geodesy, KNToosi Uni. Tech.,Department of Geodesy, K.N. Toosi University of Technology, 470 Mirdamad Ave. West, Box 15875-4416, 19697 Tehran, Iran
-
(creator_code:org_t)
- The netherlands : Elsevier, 2011
- 2011
- Engelska.
-
Ingår i: Advances in Space Research. - The netherlands : Elsevier. - 0273-1177 .- 1879-1948. ; 48:8, s. 1341-1358
- Relaterad länk:
-
http://www.sciencedi...
-
visa fler...
-
https://urn.kb.se/re...
-
https://doi.org/10.1...
-
https://urn.kb.se/re...
-
visa färre...
Abstract
Ämnesord
Stäng
- The Earth’s gravity field modelling is an ill-posed problem having a sensitive solution to the error of data. Satellite gravity gradiometry (SGG) is a space technique to measure the second-order derivatives of geopotential for modelling this field, but the measurements should be validated prior to use. The existing terrestrial gravity anomalies and Earth gravity models can be used for this purpose. In this paper, the second-order vertical–horizontal (VH) and horizontal–horizontal (HH) derivatives of the extended Stokes formula in the local north-oriented frame are modified using biased, unbiased and optimum types of least-squares modification. These modified integral estimators are used to generate the VH and HH gradients at 250 km level for validation purpose of the SGG data. It is shown that, unlike the integral estimator for generating the second-order radial derivative of geopotential, the system of equations from which the modification parameters are obtained is unstable for all types of modification, with large cap size and high degree, and regularization is strongly required for solving the system. Numerical studies in Fennoscandia show that the SGG data can be estimated with an accuracy of 1 mE using an integral estimator modified by a biased type least-squares modification. In this case an integration cap size of 2.5° and a degree of modification of 100 for integrating 30′ × 30′ gravity anomalies are required.
Ämnesord
- NATURVETENSKAP -- Geovetenskap och miljövetenskap -- Multidisciplinär geovetenskap (hsv//swe)
- NATURAL SCIENCES -- Earth and Related Environmental Sciences -- Geosciences, Multidisciplinary (hsv//eng)
- NATURVETENSKAP -- Geovetenskap och miljövetenskap -- Geofysik (hsv//swe)
- NATURAL SCIENCES -- Earth and Related Environmental Sciences -- Geophysics (hsv//eng)
Nyckelord
- * First- and second-order Paul’s coefficients; * Global root mean square error; * Horizontal–horizontal gradients; * Truncation coefficients; * Vertical–horizontal gradients
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
Hitta via bibliotek
Till lärosätets databas