HELIOSPHERIC TOMOGRAPHY USING INTERPLANETARY SCINTILLATION OBSERVATIONS - 1 - COMBINED NAGOYA AND CAMBRIDGE DATA

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.