@article{95be3304056f42098e33038ef09cb5c5,
title = "The two wide-angle imaging neutral-atom spectrometers (TWINS) NASA mission-of-opportunity",
abstract = "Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS) is a NASA Explorer Mission-of-Opportunity to stereoscopically image the Earth's magnetosphere for the first time. TWINS extends our understanding of magnetospheric structure and processes by providing simultaneous Energetic Neutral Atom (ENA) imaging from two widely separated locations. TWINS observes ENAs from 1-100 keV with high angular (∼4°×4°) and time (∼1-minute) resolution. The TWINS Ly-α monitor measures the geocoronal hydrogen density to aid in ENA analysis while environmental sensors provide contemporaneous measurements of the local charged particle environments. By imaging ENAs with identical instruments from two widely spaced, high-altitude, high-inclination spacecraft, TWINS enables three-dimensional visualization of the large-scale structures and dynamics within the magnetosphere for the first time. This {"}instrument paper{"} documents the TWINS design, construction, calibration, and initial results. Finally, the appendix of this paper describes and documents the Southwest Research Institute (SwRI) instrument calibration facility; this facility was used for all TWINS instrument-level calibrations.",
keywords = "ENA, ENA instrumentation, Energetic neutral atom imaging, Geocorona, Magnetosphere, Space plasma calibration facility",
author = "McComas, {D. J.} and F. Allegrini and J. Baldonado and B. Blake and Brandt, {P. C.} and J. Burch and J. Clemmons and W. Crain and D. Delapp and R. Demajistre and D. Everett and H. Fahr and L. Friesen and H. Funsten and J. Goldstein and M. Gruntman and R. Harbaugh and R. Harper and H. Henkel and C. Holmlund and G. Lay and D. Mabry and D. Mitchell and U. Nass and C. Pollock and S. Pope and M. Reno and S. Ritzau and E. Roelof and E. Scime and M. Sivjee and R. Skoug and Sotirelis, {T. S.} and M. Thomsen and C. Urdiales and P. Valek and K. Viherkanto and S. Weidner and T. Ylikorpi and M. Young and J. Zoennchen",
note = "Funding Information: Acknowledgements The TWINS Mission-of-Opportunity is dedicated to the memory of Phil Barker, who was the original TWINS Project Manager and served in that capacity until his death in 2003. Phil was a good friend to the entire TWINS team, and his brave battle with colon cancer throughout the development of much of the TWINS mission hardware was an inspiration to the team. Figure 8 shows the plaque that was placed on the TWINS instrument (under the LAD) to commemorate his dedication to this project. We thank Eric Archuleta, Donna Avila, Steve Battel, Randy Bremmer, Kent Bress, Dana Burket, Jim Byrd, Butch Carruth, Rick Claffy, Jim Cravens, Bill Davis, Dot Delapp, Greg Dirks, Eric Dors, Karen Douglas, Reginald Eason, Gus Escobar, Brian Gupta, Mike Henderson, Brad Johnson, Roger Kraus, Mike Lampton, Glen Martin, Dave Mengers, Thomas E. Moore, A. M. Niazy, Enold Pierre-Louis, Jillian Redfern, Mark Schattenburg, Mike Van Dyke, Mike Wallace, and the numerous other dedicated men and women who contributed to the success of the TWINS program. In addition, we are particularly indebted to Wendy Mills for all of her help in assembling and editing this paper and to Colonel John D. Cunningham, USAF (Ret.) for his crucial support of the TWINS project. TWINS was funded by the National Aeronautics and Space Administration through the GSFC Explorer{\textquoteright}s Office.",
year = "2009",
month = feb,
doi = "10.1007/s11214-008-9467-4",
language = "English (US)",
volume = "142",
pages = "157--231",
journal = "Space Science Reviews",
issn = "0038-6308",
publisher = "Springer Netherlands",
number = "1-4",
}