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

摘要

The Air Force/NASA Solar Mass Ejection Imager (SMEI) was launched January 6, 2003, and 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 sweeps the sky every orbit by viewing 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 the heliospheric solar wind density. The tomography is capable of analyzing time-dependent phenomena such as evolving corotating heliospheric structures and more transient, discrete events such as coronal mass ejections (CMEs). This improved analysis is being applied to the SMEI data.