Elephant Approach Early Warning System
How does the System Work?
The system relies on animal movement [Elephants as well as other animals like Wild boar, Deer, Bear, Tiger, Leopard, etc.,] being detected by the light sensors, which get activated when a beam of laser on the perimeter is intercepted. The sensed interception is passed onto the central control unit that is programmed to act differently based on the nature of the interception such as its duration and height above ground. On detecting elephant/small animal movement a loud alarm system and high frequency tweeters are turned on for a short duration. The high frequency noise is designed to disorient and scare away the animals, while the loud alarm system is to warn humans within the test area of the approach of wildlife into their vicinity.

Detailed description

The system is designed to work between dusk and dawn. A light sensor has been calibrated to activate the circuit at sunset and deactivate on sunrise. The circuit on an average will be activated for 12 hrs per day. When the circuit is activated the lasers are powered on and the beam is directed at the light sensor continuously. 

The two key parameters are the height of the laser beam that is intercepted and the duration of the interception. Large animals such as an adult or a sub adult elephant will interrupt both the lower and upper beam of light on entering the perimeter area. The upper beam is expected to be interrupted for a set duration for the circuit to determine that the perimeter has been breached. All other smaller animals will intercept the lower beam and the duration for detection is kept at 2 seconds to avoid false triggers by falling leaves, flying birds etc.

When a small wild animal like a wild boar, leopard or bear happens to walk thru the perimeter of the fence, the lower laser beam is intercepted. The circuit waits on the interruption for 2 seconds after which it activates the ultrasound tweeter for 30 seconds. 

When a large animal like an elephant intercepts the upper beam operating at a height of 7 ft and the lower beam, the control unit waits on the interruption for 2 seconds. At the end of 2 seconds, loud alarm sirens are switched on along with beacon lights to identify the area of breach. The alarms are turned on for a full minute at the first breach. On all subsequent breaches within the next one hour, the alarm is turned on only for 30 seconds.

System is currently under field trials.