منابع مشابه
Space VLBI at Low Frequencies
At sufficiently low frequencies, no ground-based radio array will be able to produce high resolution images while looking through the ionosphere. A space-based array will be needed to explore the objects and processes which dominate the sky at the lowest radio frequencies. An imaging radio interferometer based on a large number of small, inexpensive satellites would be able to track solar radio...
متن کاملSpace - VLBI observations of OH masers
We report on the first space-VLBI observations of the OH masers in two main-line OH transitions at 1665 and 1667 MHz. The observations involved the space radio telescope on board the Japanese satellite HALCA and an array of ground radio telescopes. The maps of the maser region and images of individual maser spots were produced with an angular resolution of 1 mas, which is several times higher t...
متن کاملSpace Vlbi Observations of Mkn 501
We present here two epochs of Space VLBI Observations at 18 cm of the BL-Lac type object Mkn 501. Thanks to the high resolution of these new data we have found that the inner jet is centrally brightened at its beginning but becomes extended and limb brightened at ∼ 8 mas from the core. Moreover a comparison between the two epochs shows the presence of a proper motion with apparent velocity = 6....
متن کاملSpace - VLBI phase - reference mapping and astrometry
We present 5 GHz space-VLBI observations of the quasar pair B 1342+662 / B 1342+663 that demonstrate the feasibility of phase-reference techniques using an antenna in space. The space-based data were taken by the satellite HALCA, of the space-VLBI mission VSOP. From residual (referenced) phases we derive an upper bound of 10 meters to the uncertainty of the spacecraft orbit reconstruction. An a...
متن کاملThe S2 VLBI Correlator: A Correlator for Space VLBI and Geodetic Signal Processing
A unique lag-based VLBI correlator system has been developed for the purpose of supporting both S2-based Space VLBI observations in the Japanese-led VSOP mission and the Canadian Geodetic VLBI program. The system architecture has been designed so that replication of a small number of modules can be used to construct systems with a wide range of sizes. Optimized for a large correlator, the desig...
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ژورنال
عنوان ژورنال: International Astronomical Union Colloquium
سال: 1991
ISSN: 0252-9211
DOI: 10.1017/s0252921100013154