Patent ID: 7612707

Claim:
A detection system comprising: a sensor including a receiver for obtaining over a predetermined period of time a plurality of scene signals representing a scene viewed by the sensor; a memory communicatively coupled to the sensor, the memory configured to store a predetermined number of the scene signals; and a signal processor communicatively coupled to at least one selected from the group consisting of the sensor and the memory, the signal processor including: a signal characteristics module configured to determine a plurality of signal characteristics for each scene signal stored in the memory, each signal characteristic defining an aspect of the respective scene signal; a compilation module configured to determine a representative value of each signal characteristic based on the signal characteristics of the scene signals stored in the memory; and an assessment module configured to obtain a first scene signal from the sensor and to compare each of a plurality of signal characteristics of the first scene signal to the representative value of the respective signal characteristic to determine whether each signal characteristic has changed.