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dc.creatorKo, Ung Dai, 1970-
dc.date.accessioned2012-09-24T18:10:45Z
dc.date.available2012-09-24T18:10:45Z
dc.date.created2008-05
dc.date.issued2012-09-24
dc.identifier.urihttp://hdl.handle.net/2152/17977
dc.descriptiontext
dc.description.abstractThe motivation for this research was an improvement of the quality of the Earth’s gravity solutions from the GRACE mission data through an instrument-level study. The objective was a better understanding of the characteristics and sources of the highfrequency noise in the range of (0.02 ~ 0.1 Hz) in the dual one-way ranging (DOWR) and its effect on the gravity solution. For this purpose, the mathematical model of the DOWR observation was derived and the Allan variance was computed to establish an upper bound on the level of frequency instability of the ultra-stable oscillators (USO) to determine their contribution to the high-frequency noise. Because they are dominated by the high-frequency noise, the postfit residuals of the time derivative of the DOWR ranges were also examined to evaluate the contributions of various other factors such as system noise from the microwave signal receiver, external influences, and internal influences. The results indicate that the system noise is the dominant source of the excessive highfrequency noise. As one method of mitigation, a tighter bandwidth filter was applied to the DOWR processing, resulting in modest improvements in gravity solutions.en_US
dc.format.mediumelectronic
dc.language.isoengen_US
dc.rightsCopyright is held by the author. Presentation of this material on the Libraries' web site by University Libraries, The University of Texas at Austin was made possible under a limited license grant from the author who has retained all copyrights in the works.
dc.subject.lcshGRACE (Artificial satellites)
dc.subject.lcshGravitation
dc.subject.lcshRange-finding
dc.titleAnalysis of the characteristics of grace dual one-way ranging systemen_US
dc.description.departmentAerospace Engineeringen_US
thesis.degree.departmentAerospace Engineeringen_US
thesis.degree.disciplineAerospace Engineeringen_US
thesis.degree.grantorThe University of Texas at Austin
thesis.degree.levelDoctoralen_US
thesis.degree.nameDoctor of Philosophyen_US


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