Answer:
A perimeter intrusion detection system (PIDS) is a device or sensor that detects the presence of an intruder attempting to breach the physical perimeter of a property, building, or other secured area.
the use of buried sensor for perimeter intrusion detection system, becomes very popular due to the advantage of been a discreet or even an invisible detection system and avoiding the need to build an above-the-ground fence to protect the perimeter due to costs or environmental reasons
Explanation:
<em>Description of 3 systems:</em>
Barrier-Mounted :Fence Intrusion Detection System
PIDS deployed on or in conjunction with a fence or other physical barrier (e.g. DAS cable or other motion sensors mounted on a fence).
Ground-based or Below-ground
:
PIDS deployed below ground (again a DAS cable can be used or pressure sensitive cable or electromagnetic field). These do not require a physical barrier.
Free-Standing
PIDS deployed above ground that do not need to be installed on or in conjunction with a physical barrier (e.g. bistatic microwave link).
Example of one PIDS system I have seen deployed in a familiar location is the ones at the prison which is a barrier mounted or some inairports that prevent small to cause harm to small animals.