inertial measurement unit

Apollo Inertial Measurement Unit

Apollo IMU, where Inertial Reference Integrating Gyros (IRIGs,Xg,Yg,Zg) sense attitude changes, and Pulse Integrating Pendulous Accelerometers (PIPAs,Xa,Ya,Za) sense velocity changes

An inertial measurement unit (IMU) is an electronic device that measures and reports a body's specific force, angular rate, and sometimes the orientation of the body, using a combination of accelerometers, gyroscopes, and sometimes magnetometers. IMUs are typically used to maneuver aircraft (an attitude and heading reference system), including unmanned aerial vehicles (UAVs), among many others, 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. A wireless IMU is known as a WIMU.