SEST Correlator

The SEST Correlator
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As part of a Memorandum of Understanding between the ATNF and the Onsala Space Observatory of the Swedish National Facility for Radio Astronomy, the ATNF has agreed to supply a wideband digital autocorrelation spectrometer to the SEST Observatory in Chile.

Initially, this correlator will provide up to 2048 spectral channels on each of two input signals over bandwidths of up to 1GHz. The design will incorporate the option for a future upgrade of the maximum bandwidth to 2GHz. This is a significant increase in performance over existing ATNF correlators which are limited to 512 spectral channels over a maximum bandwidth of 256MHz. The wide bandwidth correlator is required at SEST particularly for extragalactic spectral line observations at millimeter wavelengths. It will replace the existing acousto-optic spectrometers. For more details see the SEST Correlator Specification.

One of the major technological challenges in this project is the design of a sampler capable of digitising the input signals at rates up to 4GSamples/sec. Initially a 1GHz bandwidth, 2GSample/sec sampler will be constructed using commercial components whilst the 2GHz bandwidth sampler will be implemented on a custom designed indium phosphide integrated circuit which will be one component of the Special Executive Project.

The ATNF also has a need for a wideband correlator, particularly in the area of pulsar astronomy, where the wide bandwidths are required to provide an incease in sensitivity. The wideband pulsar correlator will be very similar to the SEST correlator, differing only in the provision of an extra output memory bank, a facility which is peculiar to its application to pulsar measurements.

More information can be obtained from:

For the First Spectrum Images follow this link.