Stardust–NExT NAVCAM calibration and performance

Abstract

NASA’s Stardust–NExT mission used the Stardust spacecraft to deliver a scientific payload, including a panchromatic visible camera designated NAVCAM, to a close flyby of Comet 9P/Tempel 1 in February 2011. Proper interpretation of the NAVCAM images depends on accurate calibration of the camera performance. While the NAVCAM had been calibrated during the primary Stardust mission to Comet 81P/Wild 2 in 2004, that calibration was incomplete and somewhat lacking in fidelity. Substantial improvements in the NAVCAM calibration were achieved during Stardust–NExT in the areas of geometric correction, spatial resolution, and radiometric calibration (in particular, zero-exposure signal levels, shutter time offsets, absolute radiometric response, noise, and scattered light characterization). These improvements will allow upgrades to the calibration of images returned from the Stardust primary mission as well as high-quality calibration of the Stardust–NExT images. The upgraded calibration results have been incorporated into the Stardust–NExT image processing pipeline via new routines and updated constants and files in preparation for archiving calibrated images in the NASA Planetary Data System.