Calibration Results for the COR-1 Coronagraph on STEREO/SECCHI

COR-1 is the inner coronagraph of the Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) instrument suite aboard the two STEREO spacecraft. COR-1 is a classic Lyot internally occulting coronagraph, observing the solar corona in broadband red light around 656 nm, from 1.35 to 4 solar radii. A linear polarizer is used to suppress scattered light, and to extract the polarized brightness signal from the solar corona. Calibration was performed in the Naval Research Laboratory vacuum tunnel facility previously used for the LASCO experiment aboard SOHO. We report on the results for scattered light, photometric calibration, resolution, and polarization. All performance requirements are met or exceeded. Based on these results, we demonstrate that COR-1 will be able to carry out its scientific mission.