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Meeting notes

7 Aug 2014

Research Plan

1. Investigate optimal filtering in some specific telescope configurations:

Let's adopt the following configurations:

• JVLA 1.4 GHz (try placing the passband at the first or second null)

• MeerKAT 700 MHz (passband at first null)

• LOFAR HBA 150 MHz (passband at first null)

• VLBI/EVN -- check with Roger Deane for a realistic scenario. Here, the primary beam will be a lot bigger than the FoV, so what we actually want to aim for is less source suppression (bigger FoV) at the same data rate.

Use NVSS or SKADS (S^3) to make a realistic sky model for the first three.

In each case the following needs to be worked out:

• What's the critical sampling rate of each telescope (i.e. the time it takes the longest baseline to traverse 1/2 dish size in the uv-plane)

• What is the best passband/source suppression we can achieve at that sampling rate, using e.g. 50 MHz frequency channels, with what WF. Produce plots of the source suppression as a function of radius, out to 20-30deg.

• what is the compression ratio, with and without baseline-dependent averaging

• what is the corresponding sensitivity penalty (noise ratio)

2. Investigate PSF behaviour

Look for ways to approximate the position-variable PSF with some kind of analytic correction function. I.e. PSF(l,m;l0,m0) = PSF0(dl,dm)*F(dl,dm,l0,m0). Here, PSF0(l,m) is the nominal PSF, PSF(l,m;l0,m0) is the PSF at position l0,m0, and F is the correction function.