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CORRELATOR BOARDS

There are four independent correlator boards available in the correlator spectrometer. Each board can be assigned any available bandwidth, center frequency, sampling level, polarization, and number of channels. Note though that for purposes of Doppler correction the boards can only be configured to work as four independent boards or as one joined system. That is, two boards cannot be overlapped and centered on one frequency while the other two are set to another frequency (Figure 2).


The top two images show the possible configurations of the correlator boards -- acting as four independent boards and acting together, respectively, while the bottom panel exemplifies an observing strategy not allowed with the current system.

The options are detailed below:


Table 3: Possible Correlator Configurations
Sampling Max BW Pol/sbc lags/sbc Resolution
  per sbc     at 1420MHz
9-level 25MHz 1 2048 2.6 km/s
9-level 25MHz 2 1024 5.2 km/s
3-level 25MHz 2 2048 2.6 km/s
3-level interleaved 50MHz 1 4096 2.6 km/s
3-level interleaved 50MHz 2 2048 5.2 km/s
3-level Stokes 25MHz - 2048 2.6 km/s


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Next: INTEGRATION TIME (per Data Up: Spectral-Line Observing at AO Previous: Calibration Scans on Continuum
koneil@naic.edu