  We demonstrate that angle-resolved soft x-ray spectroscopy can resolve
absorption by inequivalent oxygen sites and by different orbitals belonging to
the same site in NaV2O5. By rotating the polarization direction, we see a
dramatic change in the absorption spectra at the oxygen K edge. Our theory
identifies the detailed composition of the spectra and predicts a correct
energy-ordering of the orbitals of three inequivalent oxygen atoms. Because
different orbitals dominate absorption spectra at different energies and
angles, one can excite at a specific site and ``orbital''. In contrast,
absorption at the vanadium L edge does not show large changes when varying the
polarization direction. The reason for this is that different excitation
channels (involving different initial states for the excited electron) overlap
in energy and vary in compensating ways, obscuring each channel's sensitive
polarization dependence.
