1-GHz bandwidth digital spectro-correlator system for the Nobeyama Mllimeter Aray

We have developed 1-GHz bandwidth digital spectro-correlator system for the Nobeyama Millimeter Array (NMA). It consists of 2Gsample/sec.2bit analog-t o-digital (A/D) converters and an ultra-wide band digital correlator. We de veloped two kinds of special-purpose LSI having functions of delay compensa tion and correlation, respectively. With these LSIs, the ultra-wide band di gital correlator realizes 1024-MHz bandwidth spectroscopy with 128-channel resolution for 15-correlation data. This system allows us to observe radio continuum emission with about a two-times better signal-to-noise ratio than that of the previous correlator system. We started common-use observations with this new system from 1997 March; the system has been extended in orde r to obtain 21-correlation data for a 7-element "Rainbow" (NMA + 45-m teles cope) interferometer system.