ASKAP PSF Simulator
Observing/Imaging Parameters	PSF Image UV Coverage ANT Positions Baselines
Array Configuration: BETA ASKAP-12 ASKAP-36 Declination: +15° 0° -15° -30° -45° -60° -75° Duration: 5m 1h 8h Weighting: Natural Wiener Robustness: -1 0 +1 +2 Tapering: None 10" 30" 90" 180"
PSF Characteristics (XX Polarisation)
Restoring Beam: N/A" x N/A", P.A.=N/A° RMS: (see notes below) N/A mJy/beam PSF Max and Location: N/A percent of peak (N/A, N/A) PSF Min and Location: N/A percent of peak (N/A, N/A) View full-resolution image of PSF Download FITS-format image of PSF

A file containing all of the available PSF characteristics is available in comma-separated (CSV) format.

The PSF images are produced by the ASKAPsoft imager. First we simulate a single-beam observation with the given array configuration of a blank field. We use a 1MHz channel at 1.4 GHz, and assume a system temperature of 50K. This measurement set is then imaged using the relevant preconditioning. This produces the correctly-weighted PSF, which is normalised to a peak of 1.0. This is the image shown in the PSF images above - the colour map runs from -0.1 (black) to 0.5 (white). The imager also produces a residual image, from which we measure the noise (see below). Running this in ASKAPsoft uses the same gridding algorithms as the ASKAP pipeline will - the simulated observation uses the AWProject gridder (taking into account the primary beam), but the imaging uses WProject, so that no primary beam correction is made.

The RMS noise is listed for XX polarisation only (σ_XX), and is measured from the residual image. The bandwidth used for all images is a single 1MHz channel. For Stokes I, σ_I=√ (σ_XX²+σ_YY²)/2=σ_XX/√ 2(for unpolarised sources) when I is defined as I=(XX+YY)/2 (as is typical for synthesis arrays). Alternatively, σ_I=√ (σ_XX²+σ_YY²)=√ 2·σ_XX(for unpolarised sources) when I is defined as I=XX+YY (as is often used for single-dish).