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WMAP: A Radiological Analysis

Pierre-Marie Robitaille
Year: 2007
In this work, results obtained by the WMAP satellite are analyzed by invoking established practices for signal acquisition and processing in nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI). Dynamic range, image reconstruction, signal to noise, resolution, contrast, and reproducibility are specifically discussed. WMAP images do not meet accepted standards in medical imaging research. WMAP images are obtained by attempting to remove a galactic foreground contamination which is 1,000 times more intense than the desired signal. Unlike water suppression in biological NMR, this is accomplished without the ability to affect the signal at the source and without a priori knowledge. Resulting WMAP images have an exceedingly low signal to noise (maximum 1?2) and are heavily governed by data processing. Final WMAP internal linear combination (ILC) images are made from 12 section images. Each of these, in turn, is processed using a separate linear combination of data. The WMAP team extracts cosmological implications from their data, while ignoring that the ILC coefficients do not remain constant from year to year. In contrast to standard practices in medicine, difference images utilized to test reproducibility are presented at substantially reduced resolution. ILC images are not presented for year two and three. Rather, year-1 data is signal averaged in a combined 3-year data set. Proper tests of reproducibility require viewing separate yearly ILC images. Fluctua- tions in the WMAP images arise from the inability to remove the galactic foreground, and in the significant yearly variations in the foreground itself. Variations in the map outside the galactic plane are significant, preventing any cosmological analysis due to yearly changes. This occurs despite the masking of more than 300 image locations. It will be advanced that any ?signal? observed by WMAP is the result of foreground effects, not only from our galaxy, but indeed yearly variations from every galaxy in the Universe. Contrary to published analysis, the argument suggests there are only questionable findings in the anisotropy images, other than those related to image processing, yearly galactic variability, and point sources. Concerns are also raised relative to the validity of assigning brightness temperatures in this setting.