1305.0116 (Atsushi J. Nishizawa et al.)

Reconstruction of Missing Data in the Sky using Iterative Harmonic Expansion    [PDF]

Atsushi J. Nishizawa, Kaiki Taro Inoue

Missing fluctuations in masked regions in the sky can be reconstructed from fluctuations in the surrounding unmasked regions if they are sufficiently smooth. We propose to reconstruct such missing fluctuations by iteratively applying a spherical harmonic expansion to fluctuations in the unmasked region. The accuracy of reconstruction depends on the mask geometries, the spectrum of underlying density fluctuations, and the number of iterations. For Gaussian fluctuations with the Harrison-Zel'dovich spectrum, our method provides more accurate restoration than naive methods using the brute-forth matrix inversion or the singular value decomposition.

View original: http://arxiv.org/abs/1305.0116