Navigation Error Analysis of Atom Interferometer Inertial Sensor

The recent development of the atom interferometer and its demonstration as an inertial sensor of acceleration and rotation rate augur a new generation of inertial navigation systems that would rival today's satellite navigation accuracy at the few-meter level. This paper reviews the principles of inertial measurement using the atom interferometer from a rudimentary viewpoint to illustrate the fundamentals and to highlight some of the potential shortcomings with a particular type, the cold-atom interferometer. One of these shortcomings is the fact that this interferometer requires a finite period of time during which the atoms are prepared (cooled) before they enter the interferometer and respond to its dynamics relative to an inertial frame. This lapse in the measurement duty cycle could be supplemented with very precise conventional inertial measurement units (IMUs), or eliminated with multiple, interleaved atom interferometers. Error analyses show that cold-atom interferometric IMUs that capture 50 percent of the dynamics must be coupled with conventional IMUs that are 50 times more accurate than typical navigation-grade units to sustain a horizontal position error of under 5 m (root mean square) after 1 h.