An inertial measurement unit (IMU) is an electronic device that measures and reports a body's specific force, angular rate, and sometimes the magnetic field surrounding the body, using a combination of accelerometers and gyroscopes, and sometimes, magnetometers. IMUs are typically used to maneuver aircraft, including UAVs, and spacecraft, including satellites and landers.
Recent developments allow for the production of IMU-enabled GPS devices. An IMU allows a GPS receiver to work when GPS-signals are unavailable, such as in tunnels, inside buildings, or when electronic interference is present.
Stanford and SCPNT Professor Mark Kasevich heads one of the world’s leading research labs studying cold atom, interferometry-based IMUs. Cold atom interferometry IMUs could be used as highly accurate gyroscopes for scientific and military purposes. Atomic interferometer gyroscopes (AIG's) and atomic spin gyroscopes (ASG's) are both used to sense rotation. Both devices are compact in size, with the possibility of being manufactured at chip scale and very high precision. One potential scientific use of AIGs and/or ASGs is to measure gravitational waves in space as predicted by Einstein.
For more information, view the Widipedia article: Inertial Measurement Unit
View Presentation: Navigation, Gravitation and Cosmology with Cold Atom Sensors, by Mark Kasevich, Atom Interferometry Group and the Stanford Center for Position, Navigation and Time, 2014.
View Presentation: Precision Navigation Sensors based on Atom Interferometry by Mark Kasevich, Atom Interferometry Group and the Stanford Center for Position, Navigation and Time, 2012.