Abstract
We consider the problem of mapping with ultra-high angular resolution using a space—ground radio interferometer with a space antenna in a high orbit, whose apogee height exceeds the radius of the Earth by a factor of ten. In this case, a multielement interferometer essentially degenerates into a two-element interferometer. The degeneracy of the close-phase relations prevents the use of standard methods for hybrid mapping and self-calibration for the correct reconstruction of images. We propose a new phaseless mapping method based on methods for the reconstruction of images in the complete absence of phase information, using only the amplitudes of the spatial-coherence function of the source. In connection with this problem, we propose a new method for the reliable solution of the phase problem, based on optimizing information-carrying nonlinear functionals, in particular, the Shannon entropy. Results of simulations of mapping radio sources with various structures with ultra-high angular resolution in the framework of the RADIOASTRON mission are presented.
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Translated from Astronomicheski\(\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\smile}$}}{l}\) Zhurnal, Vol. 82, No. 12, 2005, pp. 1087–1098.
Original Russian Text Copyright © 2005 by Bajkova.
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Bajkova, A.T. A solution to the problem of phaseless mapping for a high-orbit space—Ground radio interferometer. Astron. Rep. 49, 973–983 (2005). https://doi.org/10.1134/1.2139813
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DOI: https://doi.org/10.1134/1.2139813