Wavelets applied to cosmic microwave background maps: a multiresolution analysis for denoising
J. L. Sanz, F. Arg\"ueso, L. Cay\'on, E. Mart\'\inez-Gonz\'alez, R. B. Barreiro, L. Toffolatti;
MNRAS, 1999, 309, 672
ABSTRACT:Analysis and denoising of cosmic microwave background (CMB) maps are performed using wavelet multiresolution techniques.
The method is tested on
12.8x12.8deg2 maps, with the resolution resembling the experimental one expected
for future high-resolution space observations.
Semi-analytic
formulae of the variance of wavelet coefficients are given for the Haar and
Mexican Hat wavelet bases.
Results are presented for the standard cold dark
matter (CDM) model.
Denoising of simulated maps is carried out by removal of
wavelet coefficients dominated by instrumental noise.
CMB maps with a
signal-to-noise ratio, SN~1, are denoised with an error improvement factor between 3
and 5.
Moreover, we have also tested how well the CMB temperature power
spectrum is recovered after denoising.
We are able to reconstruct the
Cls up to l~1500 with errors always below 20per cent in cases with
SN>=1.
CODE: sanz99