Improved north seeking gyro

Abstract

The common north-seeking gyroscope (NSG) is a free gyroscope with damped precession such that it will align itself parallel to the Earth's spin axis. The author presents an improved NSG which still uses the Earth's spin to sense north but, instead of physical displacement, the orientation to north is determined by sensing the Earth spin rate vector through scanning horizontally with an angular rate sensor and using electronic filtering with digital signal processing to then refine the accuracy. Underlying theoretical limits of accuracy and a discussion of the primary applications are presented.<>