Basics on the continuous and discrete wavelet transform with two scales are
outlined. We study maps representing anisotropies in the cosmic microwave
background radiation (CMB) and the relation to the standard approach, based
on the C-l's, is established through the introduction of a wavelet spectru
m. We apply this technique to small angular scale CMB map simulations of si
ze similar or equal to 12.8 degrees x 12.8 degrees and filtered with a 4'.5
Gaussian beam. This resolution resembles the experimental one expected for
future high resolution experiments (e.g, the Planck mission), We consider
temperature fluctuations derived from standard, open and flat-Lambda CDM mo
dels, We also introduce Gaussian noise (uniform and non-uniform) at differe
nt S/N levels and results are given regarding denoising.