A statistical technique for processing radio interferometer data

The output of a radio interferometer is the Fourier transform of the object under investigation. Due to the limited coverage of the Fourier plane the reconstruction of the image of the source is blurred by the beam of the synthesized array. In this paper a maximum-likelihood processing technique is described that uses the statistical properties of the received noise-like signals. This technique has been used extensively in the processing of large aperture seismic arrays. This inversion method results in a synthesized beam that is more uniform, has lower sidelobes, and higher resolution than the normal Fourier transform methods. The maximum-likelihood method (MLM) algorithm was applied successfully to very long baseline (VLB) and short baseline interferometric data.