Boresight and gimbal axis alignment for the CRISM instrument

Precise knowledge of the instrument boresight was required over the gimbal range for the CRISM Instrument (Compact Reconnaissance Imaging Spectrometer for Mars), which will fly aboard the Mars Reconnaissance Orbiter. Vector metrology techniques were applied to measure both the optical axis and the axis-of-rotation of the instrument housing about its mount (gimbal axis). Boresight stability was quantified through comparison of pre-environmental and post-environmental alignment data. In addition, checks were made of the instrument internal alignment and field-of-view. Distillation of the boresight data into gimbal axis and optical axis offset knowledge allowed the calculation of the instrument boresight at all gimbal settings. Finally, alignment information was mapped into the instrument reference cube, ensuring proper instrument orientation during installation.