We report intermediate scale plasma irregularities in the polar ionosphere inferred from high-resolution radio occultation (RO) measurements using GPS (Global Positioning System) to CASSIOPE (CAScade Smallsat and IOnospheric Polar Explorer) satellite radio links. The high inclination of CASSIOPE and the high rate of signal reception by the GAP (GPS Attitude, Positioning and Profiling) RO receiver on CASSIOPE enable a high resolution investigation of the dynamics of the polar ionosphere with unprecedented detail. Intermediate scale, scintillation-producing irregularities, which correspond to 1 to 40 km scales, were inferred by applying multi-scale spectral analysis on the RO phase measurements. Using our multi-scale spectral analysis approach and satellite data (Polar Operational Environmental Satellites [POES] and Defense Meteorological Satellite Program [DMSP]), we discovered that the irregularity scales and phase scintillations have distinct features in the auroral oval and polar cap. We found that large length scales and more intense phase scintillations are prevalent in the auroral oval compared to the polar cap implying that the irregularity scales and phase scintillation characteristics are a function of the solar wind and magnetospheric forcings.