The design of a two-element correlation interferometer operating at L-band

[摘要] ENGLISH ABSTRACT: This thesis describes the design and construction of a two-element digital correlation interferometeroperating at 1.42 GHz. This instrument consists of two 92cm off set-parabolic reflectorsarranged in an east-west baseline, with a maximum length of 24m. The reflectors are out-fi tted with helical beam antennas as primary feeds, and are further equipped with low-noise front-ends. A wideband dual-conversion superheterodyne receiver processes the astronomicalsignals before digitisation. The receiver is implemented as far as possible using a ffordable off -the-shelf technologies. The cross-correlation between the two antenna signals is measured usinga 256MHz bandwidth digital FX correlator, and is implemented on a Reconfi gurable Open Architecturefor Computing Hardware (ROACH) board. The preliminary observations made withthis interferometer, suggests that it is possible to detect the sun, and some other much weakersources such as Taurus A.The design of an interferometer in general is presented, from the formulation of the underlyinginstrumental requirements, to making meridian drift scan observations. The interferometerdeveloped may serve as a demonstrator for other engineering students to gain a working knowledgeof radio interferometry, which should prove invaluable when addressing the challenges theSquare Kilometre Array (SKA) is faced with.

[发布机构] Stellenbosch University