Radio interferometric observations of scattering phenomena in the outer solar corona

The Very Large Array was used to observe a number of background radio sources through the solar wind at lambda = 3.6, 6, and 20 cm. The range of source elongations was between approximate to 1.7 - 6.5 R-circle dot and source position angles corresponded to both equatorial and polar regions. The angular broadening and scintillation properties of the sources have been used to constrain the spatial power spectrum of electron density inhomogeneities in the outer solar corona. The main results are: 1) the spatial spectrum is consistent with a power law Phi(n)(K) proportional to K-alpha-2; 2) Phi(n)(K) is significantly flatter than "Kolmogorov" with alpha approximate to 1 over spatial scales up to several tens of km; 3) The scattering measure is significantly higher in the equatorial regions than in polar regions; 4) Phi(n)(K) is highly anisotropic, the inhomogeneities being elongated in a roughly radial direction; 5) the enhanced variance observed in visibility measurements on intermediate time scales - refractive scintillation - is consistent with the spectral constraints deduced from the angular broadening observations.