  The formalism of Wiener filtering is applied to reconstruct, in terms of
spherical harmonics, the projected $4\pi$ galaxy distribution of a mock IRAS
1.2 Jy catalog with a `Zone of Avoidance' $|b| = 15^\circ$. The Singular Value
Decomposition al gorithm is utilized as an extra-regularizer in order to
stabilize the inversion. This case sheds light on the amount of useful
information contained in the data, and also suggests a method for obtaining an
`optimal' functional basis, based on our \prior knowledge, for the purposes of
likelihood analysis and Wiener reconstruction of cosmological data sets. The
applicability of such a functional basis for redshift galaxy catalogs is also
discussed.
