Statistical inversion of the LOFAR Epoch of Reionization experiment data\n model

LOFAR is a new and innovative effort to build a radio-telescope operating at\nthe multi-meter wavelength spectral window. One of the most exciting\napplications of LOFAR will be the search for redshifted 21-cm line emission\nfrom the Epoch of Reionization (EoR). It is currently believed that the Dark\nAges, the period after recombination when the Universe turned neutral, lasted\nuntil around the Universe was 400,000 years old. During the EoR, objects\nstarted to form in the early universe and they were energetic enough to ionize\nneutral hydrogen. The precision and accuracy required to achieve this\nscientific goal, can be essentially translated into accumulating large amounts\nof data. The data model describing the response of the LOFAR telescope to the\nintensity distribution of the sky is characterized by the non-linearity of the\nparameters and the large level of noise compared to the desired cosmological\nsignal. In this poster, we present the implementation of a statistically\noptimal map-making process and its properties. The basic assumptions of this\nmethod are that the noise is Gaussian and independent between the stations and\nfrequency channels and that the dynamic range of the data can been enhanced\nsignificantly during the off-line LOFAR processing. These assumptions match our\nexpectations for the LOFAR Epoch of Reionization Experiment.\n