Solar Physics 265 (1/2), 245−256, 2010
Topical issue: "Remote sensing of the innner heliosphere"
© Springer Verlag
Inclusion of in-situ velocity measurements into the UCSD time-dependent
tomography to constrain and better-forecast remote-sensing observations
B.V. Jackson, P.P. Hick, M.M. Bisi, J.M. Clover and A. Buffington
Center for Astrophysics and Space Sciences, Univ. of California, San Diego, CA
Abstract
The University of California, San Diego (UCSD) time-dependent tomography
program has been used successfully for a decade to reconstruct and forecast
coronal mass ejections from interplanetary scintillation observations. More
recently, we have extended this tomography technique to use remote-sensing
data from the Solar Mass Ejection Imager (SMEI) on board the Coriolis
spacecraft; from the Ootacamund (Ooty) radio telescope in India; and from the
European Incoherent SCATter (EISCAT) radar telescopes in northern Scandinavia.
In this article we demonstrate how in-situ velocity measurements from
space-borne instrumentation are used in addition to remote-sensing data to
constrain the time-dependent tomographic solution. Adding this information not
only yields a far more accurate and better normalized three-dimensional
(3-D) remote-sensing fit to in-situ measurements over time, but it also shows
the differences between the remote-sensing observations and in-situ
measurements within the volume accessed by the spacecraft. Combining
remote-sensing observations and in-situ measurements significantly reduces
uncertainty in extending the latter measurements to global 3-D reconstructions
that are distant in time and space from the spacecraft measurements. At Earth,
this can provide a finely-tuned real-time measurement up to the latest time
for which in-situ measurements are available, and allows forecasting beyond
this more accurate than remote-sensing observations alone allow.