Physics and Chemistry of the Earth 22 (5), 441−444, 1997
© EGS, Elsevier Science

The Solar Mass Ejection Imager

B.V. Jackson, A. Buffington and P. Hick
Center for Astrophysics and Space Sciences, UCSD, La Jolla, CA 92093−0424, USA

S.W. Kahler, S.L. Keil
Phillips Laboratory/GPSG, Hanscom AFB, MA, USA

R.C. Altrock
Phillips Laboratory/GPSS, National Solar Observatory/Sacramento Peak, Sunspot, NM, USA

G.M. Simnett
School of Physics and Space Research, University of Birmingham, Birmingham, UK

D.F. Webb
ISR, Boston College, Newtown Center, MA, USA


We are designing a Solar Mass Ejection Imager (SMEI) capable of observing Thomson-scattered signals from heliospheric density features from a spacecraft situated near 1 AU. The imager is designed to trace these features, which include coronal mass ejections, corotating structures and shock waves, to elongations greater than 90 from the Sun. The instrument may be regarded as a progeny of the heliospheric imaging capability shown possible by the zodiacal light photometers of the HELIOS spacecraft. The instrument we are designing would make more effective use of in situ solar wind data from spacecraft in the vicinity of the imager by extending their observations to the surrounding environment. An imager at Earth could allow up to three days warning of the arrival of a mass ejection from the Sun. In combination with similar instruments in deep space SMEI can be used for stereoscopic imaging of heliospheric features.