Cosmic Background Explorer (COBE) Satellite Anisotropy Experiment Data Analysis Techniques

Abstract

The COBE Differential Microwave Radiometer (DMR) experiment will measure the anisotropy of the cosmic microwave background radiation (CMBR). The initial phase of data analysis uses a ‘sparse matrix’ algorithm to convert the differential temperature data into sky maps. The sky maps are then fitted to a ‘fast’ multipole expansion in spherical harmonics. Since the CMBR anisotropy is very weak, powerful techniques are used to extract the angular unevenness of the sky from the low signal-to-noise data. Instrument signature and other systematic errors are subtracted by fitting models of these effects. Test results are presented.