Assume that a set of visibility data
)| j = 1, 2,...,N}
is given where visibility zj
observed at time j can be expressed in terms of “true visibility” defined by the brightness distribution T(x,y) and observation noise εj
)} is a given set of points in the u-v plane. It is assumed that u-v plane is gridded with the interval Δ. The dirty map obtained by
is a crude estimate of the true brightness distribution. CLEAN and MEM are two typical methods to get better estimates.