Patent ID: 8072325

Claim:
A trespass detection system comprising: an electronic-wave trespass detection sensor which is provided near a boundary of a trespass surveillance area and which has a transmitting-side leakage transmission line and a receiving-side leakage transmission line arranged parallel to each other at a predetermined space from each other; and a detection device body including a change quantity storing unit which stores a quantity of change in electric field intensity when an electronic wave leaked from the transmitting-side leakage transmission line is received on the receiving-side leakage transmission line over a predetermined period for each detection zone from a plurality of preset detection zones along a direction of extension of the electronic-wave trespass detection sensor; a change rate calculating unit calculating a rate of change per unit time of the quantity of change for each detection zone from the plurality stored in the change quantity storing unit; a statistical processing unit which statistically processes each quantity of change stored in the change quantity storing unit, a threshold value setting unit which corrects a preset threshold value for each detection zone on the basis of the result of processing by the statistical processing unit and sets a new threshold value, and a trespass detection determining unit which determines that there is trespassing by an object into a trespass surveillance area in the case where the quantity of change in electric field intensity is larger than a corrected threshold value set by the threshold value setting unit.