Interferometric visibility of a scintillating source

I calculate the distribution of the product of complex factors drawn from a bivariate Gaussian distribution. The interferometric visibility of a scint illating point source follows this distribution. I find the distributions o f the real part, the imaginary part, and the amplitude of the product. I in vestigate effects of a small, partially resolved source on the distribution . These effects depend on whether the source is elongated, and if so, on it s orientation relative to the interferometer baseline. A single sample of i nterferometric visibility, for any source, is also the product of complex f actors drawn from a bivariate Gaussian distribution.