Observations of large-scale structure in the inner heliosphere with Doppler scintillation measurements

A study of large-scale structure in the inner heliosphere based on unique and extensive Pioneer Venus Doppler scintillation data has been initiated. Preliminary results include the first observation of corotating stream structure inside 35 solar radii. Results on variations of the Doppler scintillations with solar cycle and heliocentric distance, and their implications in terms of solar wind structure and mass flux density, are discussed.