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Estimability of geodetic parameters from space VLBI observablesThe feasibility of space very long base interferometry (VLBI) observables for geodesy and geodynamics is investigated. A brief review of space VLBI systems from the point of view of potential geodetic application is given. A selected notational convention is used to jointly treat the VLBI observables of different types of baselines within a combined ground/space VLBI network. The basic equations of the space VLBI observables appropriate for convariance analysis are derived and included. The corresponding equations for the ground-to-ground baseline VLBI observables are also given for a comparison. The simplified expression of the mathematical models for both space VLBI observables (time delay and delay rate) include the ground station coordinates, the satellite orbital elements, the earth rotation parameters, the radio source coordinates, and clock parameters. The observation equations with these parameters were examined in order to determine which of them are separable or nonseparable. Singularity problems arising from coordinate system definition and critical configuration are studied. Linear dependencies between partials are analytically derived. The mathematical models for ground-space baseline VLBI observables were tested with simulation data in the frame of some numerical experiments. Singularity due to datum defect is confirmed.
Document ID
19910005323
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Adam, Jozsef
(Ohio State Univ. Columbus, OH, United States)
Date Acquired
September 6, 2013
Publication Date
July 1, 1990
Subject Category
Earth Resources And Remote Sensing
Report/Patent Number
NASA-CR-187413
NAS 1.26:187413
OSU-406
Accession Number
91N14636
Funding Number(s)
CONTRACT_GRANT: NSG-5265
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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