Device and method for containing and tracking a subject using satellite positioning data

A device to be disposed on a subject for determining whether the subject is inside or outside of a containment zone defined by a containment perimeter, the containment perimeter intersecting a portion of a structure, the device comprising:

• A positioning unit for generating position data corresponding to the position of the subject;
• the position data comprising satellite positioning data, including a carrier to noise ratio;
• and
• A processor unit, in communication with the positioning unit, configured to:
• Determine from the position data if the carrier to noise ratio is greater than a first predetermined threshold indicating that the subject is not under the structure or less than a second predetermined threshold indicating that the subject is under the structure,
• If the carrier to noise ratio is greater than the first predetermined threshold, determine from the position data if the subject is inside the containment zone or if the subject has exited the containment zone;
• and
• If the carrier to noise ratio is less than the second predetermined threshold, assign the subject to a virtual position in the containment zone different from the actual position of the subject based on the position data.