Single bad visibility out of N diluted by factor 1/N

Obviously single integs more important for snapshots!

uv tracks E-W at transit -> linear corrugations

Long duration errors (ring) -> Bessel function ripples

Additive errors add to true visiblity

RFI, crosstalk, receiver noise, atmospheric emission are additive

Multiplicative errors muliply the true visibility

Atmospheric absorption and path delays, receiver gain fluctuations are multiplicative

Multiplicative errors in the Image Plane will correspond to a convolution in the Fourier domain

Optics distortions (eg. primary beam!), pointing errors, shadowing, smearing are convolutions