Bv. Jackson et al., HELIOSPHERIC TOMOGRAPHY USING INTERPLANETARY SCINTILLATION OBSERVATIONS - 1 - COMBINED NAGOYA AND CAMBRIDGE DATA, J GEO R-S P, 103(A6), 1998, pp. 12049-12067
We have produced a computer assisted tomography program that optimizes
a three-dimensional model to fit observational data. We have used thi
s program with interplanetary scintillation data from Nagoya, Japan, a
nd Cambridge, England. The program iterates to a least squares solutio
n fit of observed data using solar rotation and solar wind motion to p
rovide perspective views of each point in space accessible to the obse
rvations. We plot the optimized model as Carrington maps in velocity V
and density N-e for the two data sets with resolutions of 10 degrees
in heliographic longitude and latitude. We map the model to 1 AU and c
ompare this to in situ observations from the IMP spacecraft. From this
comparison we find Delta N-e proportional to N-e(0.3). We plot Carrin
gton maps extrapolated to the solar surface to compare with Yohkoh Sof
t X ray Telescope (SXT), Sacramento Peak green line, and Mark III K-co
ronameter observations. High velocities modeled at the solar surface f
or individual rotations trace coronal holes (including polar ones) obs
erved in SXT data. Regions of high density modeled from the Cambridge
scintillation level data generally show a high correlation with region
s of high solar activity observed as bright in Yohkoh SXT and green li
ne observations. There is also a general correspondence of the regions
of high density and the areas which are bright in K-coronameter obser
vations.