1. A method of measuring a magnetic dipole by using spatial geometry characterization, the method comprising: determining position data (of point O) and orientation of the magnetic dipole, comprising removing background magnetic field in a target area; placing an object having a permanent magnetic dipole in the target area; sensing a magnetic field of the object using a plurality of magnetic sensors distributed on two sensor planes, wherein a first sensor plane is opposite to a second sensor plane, and the first and the second sensor planes are parallel to each other; identifying position points (A and B) of a maximum magnetic field of the object on the two sensor planes; and deriving a position of the object by solving Equation 6 (Eq.6) and Equation 7 (Eq.7): OA OB = B A_AB // B B_AB // 3 = B A_AB ⊥ ⁢ B B_AB ⊥ 3 ( Eq. ⁢ 6 ) tan ⁢ ⁢ θ = B A_AB ⊥ 2 ⁢ B A_AB // = B B_AB ⊥ 2 ⁢ B B_AB // ( Eq. ⁢ 7 ) wherein OA is a distance from point O to point A; OB is a distance from point O to point B; B A — AB∥ is a dipole generated magnetic field component at point A, and said component is in a direction parallel to a line connecting point A to point B; B B — AB∥ is a dipole generated magnetic field component at point B, and said component is in the direction parallel to the line connecting point A to point B; B A — AB⊥ is a dipole generated magnetic field component at point A, and said component is in a direction perpendicular to the line connecting point A to point B; B B — AB⊥ is a dipole generated magnetic field component at point B, and said component is in the direction perpendicular to the line connecting point A to point B; and θ is an angle between a position vector of a field measurement at point O and the line connecting point A to point B.