Quasi-Static Magnetic-Field Technique for Determining Position And Orientation

Multiaxis generation and sensing of magnetic-dipole fields is used to determine both position and orientation. The effect of conducting ground upon the fields is kept to an acceptably low level by using extremely low-frequency source-excitation signals. This technique can therefore be used in through-the-earth position-finding for applications such as drill guidance and mine rescue. The theory of operation, system-design procedures, and simulated performance data are given.