Maximum Likelihood Mapmaking is a method of creation of
maps covering a region of the sky from data
contaminated by noisy signal. The technique is
used in processing data to map the Cosmic Microwave Background,
e.g., that has multiple observations of each "pixel"
of a region of the sky, each observation
Maximum Likelihood Estimation (MLE) is used to determine
the presumed value of each pixel,
or, to make the problem tractable,
method designed to approximate it.