Interferometers with Complete Coverage of Symmetrized Domains in the U, V -Plane
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The configurations of a square interferometer suggested in Chapter 2, though provide a complete uniform coverage of the corresponding u, v -domains, are non-optimal, in the sense that they provide a different resolution in various directions; particularly, the resolution in the diagonal direction of the square is \(\sqrt 2 \) times higher than in the axial ones. It is desirable to have equal resolution in all the directions, which would take place only for a ring interferometer, when arranging k aerials uniformly around a circumference of a radius r and so covering a disk u, v -domain of the double radius. However, is this case the spacings would arrange rather non-uniformly (see Fig. 3.1). In the vicinity of the centre of the disk, the angular intervals between these are small whereas nearby the disk edge small are the radial intervals. Due to this, “holes” in the u, v -plane appear, resulting in large sidelobes far from the main one. Although the number of baselines is N id = k(k − 1) / 2, one should introduce a certain effective number of baselines N ef to take account of the mentioned irregularity of covering the u, v -plane.
KeywordsMain Beam Hexagonal System Sidelobe Level Regular Coverage Ring Interferometer
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- 4.Christiansen, W. N.and Högbom, J. A. Radiotelescopes. CUP, 1972.Google Scholar