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An improved error assessment for the GEM-T1 gravitational modelSeveral tests have been designed to estimate the correct error variances for the GEM-T1 gravitational solution that was derived exclusively from satellite tracking data. The basic method uses both independent and dependent subset data solutions and produces a coefficient-by-coefficient estimate of the model uncertainties. The GEM-T1 errors have been further analyzed using a method based on eigenvalue-eigenvector analysis, which calibrates the entire covariance matrix. Dependent satellite data sets and independent altimetric, resonant satellite, and surface gravity data sets all confirm essentially the same error assessment. The calibration test results yield very stable calibration factors, which vary only by approximately 10 percent over the range of tests performed. Based on these calibrated error estimates, GEM-T1 is a significantly improved solution, which to degree and order 8 is twice as accurate as earlier satellite derived models like GEM-L2. Also, by being complete to degree and order 36, GEM-T1 is more complete and has significantly reduced aliasing effects that were present in previous models.
Document ID
19920032048
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Lerch, F. J.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Marsh, J. G.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Klosko, S. M.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Patel, G. B.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Chinn, D. S.
(ST Systems Corp. Lanham, MD, United States)
Pavlis, E. C.
(Maryland, University College Park, United States)
Wagner, C. A.
(NOAA, National Geodetic Survey, Rockville MD, United States)
Date Acquired
August 15, 2013
Publication Date
November 10, 1991
Publication Information
Publication: Journal of Geophysical Research
Volume: 96
ISSN: 0148-0227
Subject Category
Geophysics
Accession Number
92A14672
Distribution Limits
Public
Copyright
Other

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