The use of natural signals for localization and navigation with application to centimeter sized UAVs

The vectors of the local geomagnetic field, the direction of the sun at the time, and acceleration due to gravity constitute a unique natural frame of reference at any point on earth. A combination of 3-axis magnetometer, CMOS array, and accelerometers-all in the realm of a few grams can measure these quantities. We show that measurement of these quantities at sufficient resolution uniquely identifies a location on the earth at a particular time. For night-time flying, the angle to the sun can be replaced by angles to the moon or specific stars. Point-to-point navigation can be attained through simply supplying waypoints in terms of these vectors. We calculate the accuracy of localization and orientation, as a function of sensor resolution. We find that sensor accuracy needed for localization and orientation is not far from available technology.