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- Haas, Rüdiger, 1966, et al.
(författare)
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GLONASS-VLBI: Onsala-Wettzell test observations
- 2015
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Ingår i: Proceedings of the 22nd European VLBI Group for Geodesy and Astrometry Working Meeting. - 9789892061917 ; , s. 107-111
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 3. |
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| 4. |
- Hellerschmied, Andreas, et al.
(författare)
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Scheduling VLBI observations to satellites with VieVS
- 2017
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Ingår i: International Association of Geodesy Symposia. - Cham : Springer International Publishing. - 0939-9585. - 9783319456287 ; 146, s. 59-64
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Konferensbidrag (refereegranskat)abstract
- © Springer International Publishing Switzerland 2016.Observations of satellites with Very Long Baseline Interferometry (VLBI) radio telescopes provide a variety of new possibilities such as the integration of different geodetic techniques, which is one of the main goals of GGOS, the Global Geodetic Observing System of the IAG. Promising applications can be found, among others, in the field of inter-technique frame ties. With the standard geodetic VLBI scheduling software not being prepared to use satellites as radio sources so far, such observations were complicated due to the need to carefully prepare the required interchange files. The newly developed Satellite Scheduling Module for the Vienna VLBI Software (VieVS) offers a solution to this. It allows the user to prepare VLBI schedule files in a standardized format, providing the possibility to carry out actual satellite observations with standard geodetic antennas, e.g. of the IVS network. First successful observations of GLONASS satellites, based on schedules created with the new VieVS module, took place on the baseline Wettzell-Onsala in January 2014.
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| 5. |
- Kodet, Jan, et al.
(författare)
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Co-locations of Space Geodetic Techniques on Ground and in Space
- 2014
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Ingår i: IVS 2014 General Meeting Proceedings "VGOS: The New VLBI Network", Edited by Dirk Behrend, Karen D. Baver, and Kyla L. Armstrong, Science Press (Beijing). - 9787030429742
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 6. |
- Sun, Jing, et al.
(författare)
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VLBI observations to the APOD satellite
- 2018
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Ingår i: Advances in Space Research. - : Elsevier BV. - 1879-1948 .- 0273-1177. ; 61:3, s. 823-829
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Tidskriftsartikel (refereegranskat)abstract
- The APOD (Atmospheric density detection and Precise Orbit Determination) is the first LEO (Low Earth Orbit) satellite in orbit co-located with a dual-frequency GNSS (GPS/BD) receiver, an SLR reflector, and a VLBI X/S dual band beacon. From the overlap statistics between consecutive solution arcs and the independent validation by SLR measurements, the orbit position deviation was below 10 cm before the on-board GNSS receiver got partially operational. In this paper, the focus is on the VLBI observations to the LEO satellite from multiple geodetic VLBI radio telescopes, since this is the first implementation of a dedicated VLBI transmitter in low Earth orbit. The practical problems of tracking a fast moving spacecraft with current VLBI ground infrastructure were solved and strong interferometric fringes were obtained by cross-correlation of APOD carrier and DOR (Differential One-way Ranging) signals. The precision in X-band time delay derived from 0.1 s integration time of the correlator output is on the level of 0.1 ns. The APOD observations demonstrate encouraging prospects of co-location of multiple space geodetic techniques in space, as a first prototype.
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