Magnetic sensor system

A method of operating a magnetic sensor system suitable for sensing of local variations in an ambient magnetic field caused by a mass of ferromagnetic material the magnetic sensor system having a magnetic sensor assembly including:

• a first scalar point-sensor magnetometer, the first scalar magnetometer having a first scalar magnetometer axis;
• a second scalar point-sensor magnetometer, the second scalar magnetometer having a second scalar magnetometer axis;
• a third scalar point-sensor magnetometer, the third scalar magnetometer having a third scalar magnetometer axis;
• the first scalar magnetometer, the second scalar magnetometer, and the third scalar magnetometer being fixedly mounted with respect to one another such that (i) the position of each of the scalar magnetometer axes is invariable with respect to the other scalar magnetometer axes, and (ii) when the magnetic sensor assembly is in operation, at any particular point in time,
• the first scalar magnetometer axis forms a first angle with magnetic field lines of the ambient magnetic field at a location of the magnetic sensor assembly in a first plane defined by the first scalar magnetometer axis and the magnetic field lines,
• the second scalar magnetometer axis forms a second angle with the magnetic field lines of the ambient magnetic field at the location of the magnetic sensor assembly in a second plane defined by the second scalar magnetometer axis and the magnetic field lines, and
• the third scalar magnetometer axis forms a third angle with the magnetic field lines of the ambient magnetic field at the location of the magnetic sensor assembly in a third plane defined by the third scalar magnetometer axis and the magnetic field lines;
• the first scalar magnetometer having a first scalar magnetometer operating range defined with respect to a range of values of the first angle, the second scalar magnetometer having a second scalar magnetometer operating range defined with respect to a range of values of the second angle, the third scalar magnetometer having a third scalar magnetometer operating range defined with respect to a range of values of the third angle;
• and
• the first scalar magnetometer, the second scalar magnetometer, and the third scalar magnetometer positioned with respect to one another such that, at the particular point in time, at least one of:
• the first angle is within the first scalar magnetometer operating range, the second angle is within the second scalar magnetometer operating range, and the third angle is within the third scalar magnetometer operating range;
• the method comprising:
• receiving, by a computer processor in electronic communication with the first scalar magnetometer, a first output signal from the first scalar magnetometer;
• receiving, by the computer processor in electronic communication with the second scalar magnetometer, a second output signal from the second scalar magnetometer, the second output signal being distinct from the first output signal;
• receiving, by the computer processor in electronic communication with the third scalar magnetometer, a third output signal from third scalar magnetometer, the third output signal being distinct from both the first output signal and the second output signal;
• determining, via the computer processor, which of the first output signal, the second output signal and the third output signal to use at the particular point in time in the sensing of local variations in the ambient magnetic field.

A magnetic sensor assembly suitable for use in a magnetic sensor system for sensing local variations in an ambient magnetic field caused by a mass of ferromagnetic material, the sensor assembly comprising:

• a first scalar point-sensor magnetometer, the first scalar magnetometer having a first scalar magnetometer axis;
• a second scalar point-sensor magnetometer, the second scalar magnetometer having a second scalar magnetometer axis;
• a third scalar point-sensor magnetometer, the third scalar magnetometer having a third scalar magnetometer axis;
• the first scalar magnetometer, the second scalar magnetometer, and the third scalar magnetometer being fixedly mounted with respect to one another such that (i) the position of each of the scalar magnetometer axes is invariable with respect to the other scalar magnetometer axes, and (ii) when the magnetic sensor assembly is in operation, at any particular point in time,
• the first scalar magnetometer axis forms a first angle with magnetic field lines of the ambient magnetic field at a location of the magnetic sensor assembly in a first plane defined by the first scalar magnetometer axis and the magnetic field lines,
• the second scalar magnetometer axis forms a second angle with the magnetic field lines of the ambient magnetic field at the location of the magnetic sensor assembly in a second plane defined by the second scalar magnetometer axis and the magnetic field lines, and
• the third scalar magnetometer axis forms a third angle with the magnetic field lines of the ambient magnetic field at the location of the magnetic sensor assembly in a third plane defined by the third scalar magnetometer axis and the magnetic field lines;
• the first scalar magnetometer having a first scalar magnetometer operating range defined with respect to a range of values of the first angle, the second scalar magnetometer having a second scalar magnetometer operating range defined with respect to a range of values of the second angle, the third scalar magnetometer having a third scalar magnetometer operating range defined with respect to a range of values of the third angle;
• and
• the first scalar magnetometer, the second scalar magnetometer, and the third scalar magnetometer positioned with respect to one another such that, at the particular point in time, at least one of:
• the first angle is within the first scalar magnetometer operating range, the second angle is within the second scalar magnetometer operating range, and the third angle is within the third scalar magnetometer operating range.