Estimation of Love numbers from VLBI observations
VLBI measures station displacements with high precision. Analysis of
all available observations allows detection of even weak tidal
signals. Historically one of the first results obtained by VLBI
was determination of Love numbers.
I was the first who determined crust displacements induced by polar tide
predicted by S. Newcomb in 1891. It was a part of my Ph.D. thesis (1995).
Since then I didn't lose interest to this problem.
Motivation:
- Whether Love numbers for long periods are as large as theory predicts?
- Are we able to to discriminate between theories of solid earth tides
by using VLBI estimates?
- Does uncertainty in computation of solid Earth tides and ocean
loading contribute to VLBI error budget?
- What is the best way to compute displacements due to solid Earth
tides and ocean loading>?
- Solid Earth tides, ocean loading, nutation, high-frequency Earth
orientation variations kinematically similar motion. Is it legitimate
to estimate them independently? How uncertainty in a priori model
of one effect may influence our parameter estimates of another
effect?
Some results.
- Petrov, L.Y. "VLBI measurements of the crustal deformations induced
by the polar motion", Izvestiya, Physics of the Solid Earth,
1998, N3, p.58-61 (In Russian),
English translation.
- Software package sotid for computing site
displacements due to the solid Earth tides using the frequency
domain approach. The algorithm is described in the paper
L. Petrov, C. Ma Study of harmonic site
position variations determined by VLBI, Journal of
Geophysical Research, vol. 108, No. B4, 2190,
doi: 10.1029/2002JB001801, 2003.
- Viewgraphs of the presentation
Determination of Love numbers H and L for long-period tides using VLBI
held at the 14-th Earth tide Symposium in Mizusawa
28-AUG-2000 -- 02-SEP-2000 (Postscript + gzip, 113Kb)
- Viewgraphs of the presentation
Combined analysis of VLBI and superconducting gravimeter data
held at the 15-th Earth tide Symposium in Ottawa on
02-AUG-2004 (Postscript + gzip, 328Kb)
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Last update: 20-SEP-2004 15:20:33