Patent ID: 6888353

Claim:
A magnetic anomaly homing system, comprising: a non-magnetic platform; an array of magnetic sensors coupled to said platform and arranged to define a left half of said array and a right half of said array relative to a direction of motion of said platform, said array defined by a plurality of single-axis subsystems with each one thereof having two of said magnetic sensors spaced apart from one another, said plurality of single-axis subsystems including at least first and second single-axis subsystems arranged parallel to one another in a plane such that said magnetic sensors are disposed at the vertices of a parallelogram with said first single-axis subsystem being part of said left half of said array and said second single-axis subsystem being part of said right half of said array; and processing means coupled to said magnetic sensors for generating (i) a differential total field parameter for each of said left half and said right half of said array, said differential total field parameter for said left half defined as a sum of the total magnetic field due to the presence of a magnetic anomaly at said magnetic sensors associated with said left half, and said differential total field parameter for said right half defined as a sum of the total magnetic field due to the presence of a magnetic anomaly at said magnetic sensors associated with said right half, and (ii) a gradient parameter for each of said left half and said right half of said array, said gradient parameter for said left half defined as a sum of total magnetic field gradients for said plurality of single-axis subsystems of said left half, and said gradient parameter for said right half defined as a sum of total magnetic field gradients for said plurality of single-axis subsystems of said right half, wherein at least one of (i) said differential total field parameter for said left half and said right half, and (ii) said gradient parameter for said left half and said right half, define guidance control parameters used to steer said platform to align said direction of motion with the magnetic anomaly.