Auto-Correlation Spectrometer (M.Gaylard & J.Quick)

Another data acquisition task involves using an Auto-Correlation Spectrometer to determine the output of a celestial source as a function of frequency. At present it is unclear just what form the NCCS correlator will take. The current correlator is very limited in capabilities, and there are no spares for certain critical components. The original NCCS Design envisaged the building of a second correlator with an upgraded computer interface from the present pool of spares along with reworked versions of boards as and where necessary. The working correlator was to be left untouched to avoid reliability issues. The NCCS proposed to interface this new Correlation Spectrometer to a dedicated PC running Linux to be called PC-COREL. PC-COREL would operate in an analogous manner to PC-STEER, using the same Eagle PC-14B interface card to communicate with the correlator. The NCCS would interact with PC-COREL through the standard ESRF device mechanism using NFS RPC's over Ethernet.

Tasks involved would be :

COMPLETE THE CONSTRUCTION OF THE NEW CORRELATOR,

SETUP SUITABLE PC-COREL LINUX SYSTEM,

FINALISING THE INTERFACE CABLE BETWEEN PC-COREL AND CORRELATOR,

WRITE SIMPLE CORRELATOR DEVICE DRIVER BASED ON PC-STEER INTERFACE DRIVER.

WRITE CORRELATOR DEVICE SERVER TO INTERFACE TO THE DRIVER.

Recently HartRAO acquired an Australian Long Baseline Array (LBA) Data Acquistion System (DAS). Although this was acquired to support the VLBI Space Observatory Program initiative by producing 2-bit sampled data for S2 recording, it also produces direct correlator outputs suitable for the Australian LBA Multibeam Correlator. An alternative NCCS correlator solution would be to purchase a Multibeam Correlator for HartRAO. Clearly this option needs to be urgently investigated as it directly impacts on Phase 2 manpower requirements vis-a-vis the tasks outlined above.