Cornell University has a portable 50 Mhz. pulsed Radar Interferometer system which it uses to study details of the turbulence in the ionosphere. The system (CUPRI) has been used in the past at various locations around the world to study the auroral and mid-latitude ionosphere as well as in conjunction with various rocket programs and chemical release experiments. This proposal requests support for the continuation of the observational program with campaigns in Scandanavia, cooperative programs with other rocket, radar and optical programs and analysis of past data and model development.