The GMRT back-end for interferometric observations is an FX-type digital correlator, which runs at 32 MHz. The block diagram in Fig.2.4 shows the various stages of the correlator.
Signals from each antenna pass through independent pipelines consisting of the Sampler, Delay/DPC, and the FFT sections. Signals from two independent pipelines are multiplied in the MAC section. The output of the MAC section is fed to the DAS card on the Host computer. The Host computer also controls the Delay/DPC, FFT and MAC hardware. The correlator produces the correlated output between any two signal channels of the same polarization and the same sideband, from two different antennas. However the MAC (Multiplier and Accumulator) section can be reconfigured to give all four stokes parameters for any one of the two sidebands. (Ref. S. K. Sirothia,"GMRT Correlator System",tech. repo.).
