Motion detection devices and systems are described herein. One motion detection device includes an inertial measurement unit (IMU) configured to measure velocity, orientation, and gravitational forces of the motion detection device and a computing component. The computing component can be configured to determine spectrum parameters of a mobile vehicle associated with the motion detection device using measurements from the IMU, determine IMU orientation parameters using measurements from the IMU, and estimate motion of the mobile vehicle using the spectrum parameters, the IMU orientation parameters, measurements from the IMU, and a motion estimation function.