With a model based on the numerical solution of the standard focused transport equation we investigated the acceleration of ∼ 1 keV interstellar pickup protons at a reverse shock with an obliquity of 45°. We found that the model reproduces the basic spectral features of more sophisticated hybrid codes. The model also explains in principle the Voyager 1 observations of large upstream anisotropies and intensity spikes near the termination shock associated with the newly discovered termination shock particle component. Magnetic mirroring of pick up ions at the shock plays a crucial role in this regard. We discuss how this approach can work at the actual nearly perpendicular termination shock.