Ramgen Power Systems, Inc. (RPS) is developing a family of high performance supersonic compressors that combine many of the aspects of shock compression systems commonly used in supersonic flight inlet design with turbo-machinery design practices employed in conventional axial and centrifugal compressor design. The result is a high efficiency compressor that is capable of single stage pressure ratios in excess of those available in existing axial or centrifugal compressors. A variety of design configurations for land-based compressors utilizing this system have been explored. A proof-of-concept system has been designed to demonstrate the basic operational characteristics of this family of compressors when operating on air. The test unit was designed to process ~1.43 kg/s and produce a pressure ratio across the supersonic rotor of 2.25:1. The theory of operation of this system will be reviewed along with selected results from initial performance tests.