@article{39df8ed18e9e47c4a13e41a9c137970e,
title = "Radiometric Calibration Targets for the Mastcam-Z Camera on the Mars 2020 Rover Mission",
abstract = "The Mastcam-Z Camera is a stereoscopic, multispectral camera with zoom capability on NASA{\textquoteright}s Mars-2020 Perseverance rover. The Mastcam-Z relies on a set of two deck-mounted radiometric calibration targets to validate camera performance and to provide an instantaneous estimate of local irradiance and allow conversion of image data to units of reflectance (R∗ or I/F) on a tactical timescale. Here, we describe the heritage, design, and optical characterization of these targets and discuss their use during rover operations. The Mastcam-Z primary calibration target inherits features of camera calibration targets on the Mars Exploration Rovers, Phoenix and Mars Science Laboratory missions. This target will be regularly imaged during flight to accompany multispectral observations of the martian surface. The primary target consists of a gold-plated aluminum base, eight strong hollow-cylinder Sm2Co17 alloy permanent magnets mounted in the base, eight ceramic color and grayscale patches mounted over the magnets, four concentric, ceramic grayscale rings and a central aluminum shadow post (gnomon) painted with an IR-black paint. The magnets are expected to keep the central area of each patch relatively free of Martian aeolian dust. The Mastcam-Z secondary calibration target is a simple angled aluminum shelf carrying seven vertically mounted ceramic color and grayscale chips and seven identical, but horizontally mounted ceramic chips. The secondary target is intended to augment and validate the calibration-related information derived from the primary target. The Mastcam-Z radiometric calibration targets are critically important to achieving Mastcam-Z science objectives for spectroscopy and photometric properties.",
author = "Kinch, {K. M.} and Madsen, {M. B.} and Bell, {J. F.} and Maki, {J. N.} and Bailey, {Z. J.} and Hayes, {A. G.} and Jensen, {O. B.} and M. Merusi and Bernt, {M. H.} and S{\o}rensen, {A. N.} and M. Hilverda and E. Cloutis and D. Applin and E. Mateo-Marti and Manrique, {J. A.} and G. Lopez-Reyes and A. Bello-Arufe and Ehlmann, {B. L.} and J. Buz and A. Pommerol and N. Thomas and L. Affolter and Herkenhoff, {K. E.} and Johnson, {J. R.} and M. Rice and P. Corlies and C. Tate and Caplinger, {M. A.} and E. Jensen and T. Kubacki and E. Cisneros and K. Paris and A. Winhold",
note = "Funding Information: This project was supported by the Carlsberg Foundation grants CF16-0981, CF17-0979, and CF19-0023. The project has also benefitted enormously from the technical and financial support of the Mars 2020 Project, Payload, and Science Offices at JPL. M. Merusi is supported by the European Union{\textquoteright}s Horizon 2020 research and innovation programme under the Marie Sk{\l}odowska-Curie grant agreement No 801199. Thanks to Jesse Kuik, Alexis Parkinson, Nathalie Turenne, and Evan Stanish for their assistance with calibration target and Mastcam-Z testing at the University of Winnipeg. Calibration target testing at the University of Winnipeg was supported by the Canadian Space Agency (CSA), the Natural Sciences and Engineering Research Council of Canada (NSERC), the Canada Foundation for Innovation (CFI), the Manitoba Research Innovations Fund (MRIF), and the University of Winnipeg. Acknowledgements to FORCE Technology for providing flight acceptance vibration test for the 2nd set of flight spare target free of charge, and to DuPont Electronic Materials for providing the Kapton foils used as spacers during assembly of Primary Calibration Targets. {\textregistered} Publisher Copyright: {\textcopyright} 2020, The Author(s).",
year = "2020",
month = dec,
doi = "10.1007/s11214-020-00774-8",
language = "English (US)",
volume = "216",
journal = "Space Science Reviews",
issn = "0038-6308",
publisher = "Springer Netherlands",
number = "8",
}