Radio Interferometer Telescope

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Subject classification: this is an astronomy resource.
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Introduction[edit | edit source]

This project deals with making a astronomical interferometer (a type of a radio telescope) based on the techniques of aperture synthesis. This telescope is designed to work at a radio frequency of 74 MHz.

The basic idea is to measure complex cross-correlation coefficients between voltage signals from two antennas separated by a distance, . This technique, called interferometry, is used to obtain higher angular resolution, which may not be attainable due to modest sizes of individual antenna (or dishes) involved in observations.

Methodology[edit | edit source]

We plan to use half-wave dipole antennas to sense electromagnetic waves from astronomical sources at MHz. This signal will be down-converted to MHz using a mixer, after necessary amplification. A small band around 73.9 MHz, of about MHz will be recorded using a direct-voltage recorder system. This raw, 2-bit quantized data will be stored on a PC for a later processing by customized computer programs.

These programs have been termed as `software correlator'. Our code for cross-correlation is based on lookup-table approach, details of which will be available on a separate page titled BITS Correlator.