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Correlator Configuration

This panel is only visible on the BL and ACA Instrument Setup form, i.e. when the Baseline correlator or the Atacama Compact Array correlator has been chosen.

The BL correlator configuration validator has four options for BL correlator restrictions: 4 quadrants, 2 quadrants, 1 quadrant and 2 antennas. The default is 4 quadrant i.e. the full ALMA correlator. You can change this in Select BL Correlator Type section of the Preferences $\rightarrow$ Telescope menu. As the choice is saved in the user preference file, you don't need to do so every time. The 2-antenna option was mainly used for the ALMA Test Facility two-antenna interferometer and is unlikely to be needed.

In the panel Correlator Configuration , the fields Integration Duration and Channel Average Duration are visible. Integration Duration determines the number of Dump Durations that can be specified in the special field (16 ms for cross correlations, and 1, 2, 4, 8, or 16 ms for auto-correlations) to be executed before sending data off for the spectral windows to be accumulated. The Integration Duration will be longer than the Channel Average Duration (see below) and is often a multiple of it, but it doesn't need to be. Further the Atmospheric Phase Correction Data To Save option can be chosen. To help the user to get these numbers right, the ADJUST buttons can be used.

Also visible in the Correlator Configuration panel are the drop down lists to select thr Correlator Accumulation and Local Oscillator modes and the check boxes to select the 90 or 180 degrees Walsh function to be applied. Please check the Reference Manual for further details.

Below the Correlator Configuration panel, the BaseBand Configurations specifications can be filled in. The following paragraph describes how this is done.


next up previous contents index
Next: BaseBand Configurations Up: Instrument Setup Previous: Square Law Setup   Contents   Index
The ALMA OT Team, 2011 May 20