The Cornell University Portable Radar Interferometer (CUPRI) is a 50 MHz system that has provided a wealth of data for the study of ionospheric plasma turbulence. The CUPRI data sets now include a variety of auroral and mid-latitude-E-region observations, F_region chemical release experiments, and polar mesosphere measurements. Most of our observations have been coordinated with other instrumentation to provide as full a characterization of the media being probed as possible in support of several segments of the CEDAR initiative. The proposed three year renewal will fund the continuing analysis and interpretation of these extensive data sets, the completion of an upgrade of the CUPRI digitizing sub-system to improve resolution, and the acquisition and study of three new data sets. The first new data set will be obtained from northern Scandinavia for multi-frequency study of polar mesospheric summer echoes. CUPRI will set up next to the EISCAT antennas and will provide the 3 meter component of this study. Although several papers have been recently published on PSME, it is clear that more data is needed, particularly of the type that CUPRI and EISCAT can jointly obtain. The second new data set is to be of mid-latitude E-region instabilities which are not at all understood as yet. The third set will try to reproduce the remarkable mid-latitude F-region coherent echoes seen by the MU Radar. If this latter effort is successful, then we would plan to add the power of the Arecibo incoherent scatter radar in an attempt to understand these intense turbulence upwelling regions. We plan to continue to involve students in CUPRI operations, data analysis, and data interpretation: graduate students as part of their thesis research and undergraduates as part of elective courses or project regions. *** //