Synoptic interplanetary scintillation IPS observations were taken during the summer of 1976 and autumn of 1977 on the University of Iowa COCOA-Cross radio telescope 34.3 MHz, with supplementary observations from the University of Maryland TPT array 38 MHz. A new high sampling rate 10 times per second digital system made it possible to reconstruct the IPS powerspectrum between 0.1-3.0 Hz. The observations, combined with earlier 1974 measurements of integrated IPS power scintillation index, have lead to the conclusion based on theoretical modelling that prediction of activity and associated variations in energetic solar particle events is feasible with a lead time of about 24 hours. The technique depends on the observed broadening of the IPS power spectrum as solar wind density enhancements approach the earth. This effect has been documented for both co-rotating and solar flare-associated plasma disturbances.