We report on the vibrational population of NO(2+) ions in the X2SIGMA+ and A2PI states formed by electron impact in a low-pressure ion source. The theoretical analysis includes ionization in the source as a vertical process and radiative decay of the excited A state during the flight of the resulting ion beam. The presented theoretical results allow for a consistent interpretation of high-resolution translational energy spectroscopy data of transitions between the X and A states in NO2+ during collisions with He reported previously.