Nuclear magnetic resonance gyro for inertial navigation

Since its discovery by Isidor Rabi in 1938 and his subsequent Nobel Prize in physics in 1944, scientists have been using nuclear magnetic resonance (NMR) technologies as a tool in analytic chemistry, biochemistry, and the study of atomic interactions. In 1952 General Electric proposed that a gyro could be made based on NMR technology, in particular the concept of using the intrinsic quantum property of spin was of interest, specifically the stability of a quantized angular momentum of a nucleus when subjected to a stable magnetic field. From roughly 1952 to 1980 several groups worked on the concept and development of an NMR based gyro, with some being more successful than others. While the fundamentals of the technology were understood and the concept demonstrated, the enabling technologies required to develop a compact, robust design that would operate outside of the controlled laboratory environment were not available. For the past several years Northrop Grumman has been investigating and developing a NMR-Gyro. Owing to the advancement in enabling technologies a small robust gyro package can now be produced. The current micro-NMRG design is housed in a 10 cubic centimeter package and has been tested over a limited environment. Projected size estimate for a 6 degree-of-freedom inertial measurement unit is on the order of 300 cc with a power draw of a few watts. Initial testing of the unit has shown a performance level better than any MEMS device currently available as well as approaching the performance of many fiber optic gyros. The micro-NMR-Gyro has the potential to provide the end user a high-performance device in a small robust package. Presented in this paper is a summary of the basic principles of operation and performance testing results of the hardware to date.