1. MWR: Microwave Radiometer for the Juno Mission to Jupiter
- Author
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J. G. Kempenaar, R. Williamson, M. S. Zawadski, J. K. Arballo, Neil Chamberlain, Behrouz Khayatian, T. C. Owen, B. R. Franklin, Paul G. Steffes, R. C. Hughes, M. A. Janssen, Sushil K. Atreya, Amadeo Bellotti, Jonathan I. Lunine, Richard Hodges, C. C. Wang, Scott Bolton, Sidharth Misra, Steven Levin, Andrew P. Ingersoll, Samuel Gulkis, Liming Li, K. A. Lee, Glenn S. Orton, E. Sarkissian, A. Ulloa-Severino, V. Vorperion, A. S. Sahakian, J. C. Chen, L. A. Jewell, P. J. Pingree, Henry A. Conley, Daniel Santos-Costa, D. Gautier, Michael Allison, Shannon Brown, Fabiano Oyafuso, M. S. Loo, Cheng Li, Douglas Dawson, F. Maiwald, J. E. Oswald, Damon Russell, William Hatch, E. T. Sunada, Virgil Adumitroaie, Richard Redick, A. S. Mazer, G. Bedrosian, and Amarit Kitiyakara
- Subjects
Physics ,010504 meteorology & atmospheric sciences ,Microwave radiometer ,Atmosphere of Jupiter ,Astronomy and Astrophysics ,01 natural sciences ,Jovian ,Jupiter ,Atmosphere ,Exploration of Jupiter ,Space and Planetary Science ,Brightness temperature ,Physics::Space Physics ,0103 physical sciences ,Astrophysics::Earth and Planetary Astrophysics ,Orbit insertion ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences ,Remote sensing - Abstract
The Juno Microwave Radiometer (MWR) is a six-frequency scientific instrument designed and built to investigate the deep atmosphere of Jupiter. It is one of a suite of instruments on NASA’s New Frontiers Mission Juno launched to Jupiter on August 5, 2011. The focus of this paper is the description of the scientific objectives of the MWR investigation along with the experimental design, observational approach, and calibration that will achieve these objectives, based on the Juno mission plan up to Jupiter orbit insertion on July 4, 2016. With frequencies distributed approximately by octave from 600 MHz to 22 GHz, the MWR will sample the atmospheric thermal radiation from depths extending from the ammonia cloud region at around 1 bar to pressure levels as deep as 1000 bars. The primary scientific objectives of the MWR investigation are to determine the presently unknown dynamical properties of Jupiter’s subcloud atmosphere and to determine the global abundance of oxygen and nitrogen, present in the atmosphere as water and ammonia deep below their respective cloud decks. The MWR experiment is designed to measure both the thermal radiation from Jupiter and its emission-angle dependence at each frequency relative to the atmospheric local normal with high accuracy. The antennas at the four highest frequencies (21.9, 10.0, 5.2, and 2.6 GHz) have ∼12° beamwidths and will achieve a spatial resolution approaching 600 km near perijove. The antennas at the lowest frequencies (0.6 and 1.25 GHz) are constrained by physical size limitations and have 20° beamwidths, enabling a spatial resolution of as high as 1000 km to be obtained. The MWR will obtain Jupiter’s brightness temperature and its emission-angle dependence at each point along the subspacecraft track, over angles up to 60° from the normal over most latitudes, during at least six perijove passes after orbit insertion. The emission-angle dependence will be obtained for all frequencies to an accuracy of better than one part in 10^3, sufficient to detect small variations in atmospheric temperature and absorber concentration profiles that distinguish dynamical and compositional properties of the deep Jovian atmosphere.
- Published
- 2017