  The Off-plane Grating Rocket Experiment (OGRE) is a soft X-ray grating
spectrometer to be flown on a suborbital rocket. The payload is designed to
obtain the highest-resolution soft X-ray spectrum of Capella to date with a
resolution goal of $R(\lambda/\Delta\lambda)>2000$ at select wavelengths in its
10--55 Angstrom bandpass of interest. The optical design of the spectrometer
realizes a theoretical maximum resolution of $R\approx5000$, but this
performance does not consider the finite performance of the individual
spectrometer components, misalignments between components, and in-flight
pointing errors. These errors all degrade the performance of the spectrometer
from its theoretical maximum. A comprehensive line-spread function (LSF) error
budget has been constructed for the OGRE spectrometer to identify contributions
to the LSF, to determine how each of these affects the LSF, and to inform
performance requirements and alignment tolerances for the spectrometer. In this
document, the comprehensive LSF error budget for the OGRE spectrometer is
presented, the resulting errors are validated via raytrace simulations, and the
implications of these results are discussed.
