Motion detection is a process of confirming a change in position of an object relative to its surroundings or the change in the surroundings relative to an object. This detection can be achieved by both mechanical and electronic methods. In addition to discrete, on or off motion detection, it can also consist of magnitude detection that can measure and quantify the strength or speed of this motion or the object that created it.
When motion detection is accomplished by natural organisms, it is called motion perception.
Motion can be detected by: sound (acoustic sensors), opacity (optical and infrared sensors and video image processors), geomagnetism (magnetic sensors, magnetometers), reflection of transmitted energy (infrared laser radar, ultrasonic sensors, and microwave radar sensors), electromagnetic induction (inductive-loop detectors), and vibration (triboelectric, seismic, and inertia-switch sensors). Acoustic sensors are based on: electret effect, inductive coupling, capacitive coupling, triboelectric effect, piezoelectric effect, and fiber optic transmission. Radar intrusion sensors have the lowest rate of false alarms.
iWatchU can perform the same with one or ten and even more cameras. Theoretically can control unlimited number of cameras connected to your computer via USB or Firewire interface. The application is clever enough to auto configure itself from the first time you run it. Also it is the only application for mac computers that includes an ambient light sensor meter that boosts motion detection. iWatchU informs you about intrusion events either by emailing a picture, by recording video or by internet video streaming technology. Video streaming allows you to watch the intrusion event videos through almost all web browsers, from any computer connected to the internet.