Proc. SPIE 5171, 1−5, 2004
Telescopes and Instrumentation for Solar Astrophysics,
S. Fineschi, M.A. Gummin (eds.)
© SPIE − The International Society for Optical Engineering

SMEI: Design and Development of an Earth-Orbiting All-Sky Coronagraph

B.V. Jackson, P.P. Hick and A. Buffington
Center for Astrophysics and Space Sciences, University of California San Diego

R. Gold
Johns Hopkins University/Applied Physics Laboratory

G.M. Simnett, C.J. Eyles, M.P. Cooke
School of Physics and Space Research, University of Birmingham, UK

N.R. Waltham
Space Science Department, Rutherford-Appleton Laboratory, Chilton, UK


The Air Force/NASA Solar Mass Ejection Imager (SMEI) launched January 6, 2003 is now recording whole sky data on each 100-minute orbit. Precise photometric sky maps of the heliosphere around Earth are expected from these data. The SMEI instrument extends the heritage of the HELIOS spacecraft photometer systems that have recorded CMEs and other heliospheric structures from close to the Sun into the anti-solar hemisphere. SMEI rotates once per orbit and views the sky away from Earth using CCD camera technology. To optimize the information derived from this and similar instruments, a tomographic technique has been developed for analyzing remote sensing observations of the heliosphere as observed in Thomson scattering. The technique provides 3-dimensional reconstructions of heliospheric density. The tomography program has been refined to analyze time-dependent phenomena such as evolving corotating heliospheric structures and more discrete events such as coronal mass ejections (CMEs), and this improved analysis is being applied to the SMEI data.