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| Titel |
Height biases and scale variations in VLBI networks due to antenna gravitational deformations |
| VerfasserIn |
Claudio Abbondanza, Pierguido Sarti, Leonid Petrov, Monia Negusini |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250039611
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| Zusammenfassung |
| The impact of signal path variations (SPVs) caused by antenna gravity deformations on
geodetic VLBI results is evaluated for the first time. Elevation-dependent models of
SPV for Medicina and Noto (Italy) telescopes were derived from a combination of
terrestrial surveying methods to account for gravitational deformations. After applying
these models, estimates of the antenna reference point (ARP) positions are shifted
upward by 8.9Â mm and 6.7Â mm, respectively. The impact on other parameters is
negligible. To infer the impact of antenna gravity deformations on the entire VLBI
network, lacking measurements for other telescopes, we rescaled the SPV models of
Medicina and Noto for other antennas according to their size. The effects are changes
in VLBI heights in the range [-3,73]Â mm and a significant net scale increase of
0.3 - 0.8Â ppb. This demonstrates the need to include SPV models in routine VLBI data
analysis. |
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