Pre-flight and In-flight Calibration and Performance of the Terminal
Tracking Cameras (TTCams) on the NASA Lucy Mission
Abstract
The Terminal Tracking Camera (TTCam) imaging system on the NASA Lucy
Discovery mission consists of a pair of cameras that will be used mainly
as a navigation and target acquisition system for the mission’s asteroid
encounters. However, a secondary science-focused function of the TTCam
system is to provide wide-angle broadband images over a large range of
phase angles around close approach during each asteroid flyby. The
scientific data acquired by TTCam can be used for shape modeling and
topographic and geologic analyses. This paper describes the pre-flight
and initial in-flight calibration and characterization of the TTCams,
including the development of a radiometric calibration pipeline to
convert raw TTCam images into radiance and radiance factor (I/F) images,
along with their uncertainties. Details are also provided here on the
specific calibration algorithms, the origin and archived location of the
required ancillary calibration files, and the archived sources of the
raw calibration and flight data used in this analysis.