Hey Jonathan As you say, this amounts to basically multiple copies of a smaller correlator. As long as you don't want the same antenna in two subarrays, you get this for free in the existing packetised design. You simply change the destination X engine IP addresses to assign an input to a given subarray (and you can change this at runtime). Once we get multicasting working (hopefully this year), then you can have the same antenna in multiple subarrays.
KAT will be supporting this sort of thing to allow multiple observations using subsets of the array but it's only needed for MeerKAT so I'm in no hurry to officially support it yet (my next priority is beamforming). Jason On 09 Jan 2011, at 00:28, Jonathan Landon wrote: > Has anyone created a correlator that only correlates overlapping subsets of > the antenna inputs? Suppose I have 32 inputs and want to correlate 1-16, > 8-24, 16-32. For a large phased array feed it may only be necessary to > correlate relatively near neighbors. The benefit of correlating subsets > comes if it's easier to build three 16-input correlators than one 32-input > correlator. If it's true that only subsets are needed for a large phased > array feed, then complexity and resource usage grows linearly as the number > of inputs is increased, instead of exponentially. The drawback of course is > that such an architecture could be so complicated that it just translates > computational burden into longer development time and complexity. Does > anyone have a sense if this may be a bad idea or if anyone has done it? > > Thanks, > Jonathan Landon > > >
