Mono-static systems are “transceivers”. The same unit acts as transmitter and receiver, similar to military radars. The system sends a electromagnetic pulse that bounces back from the moving object in the detection field. The system senses moving bodies (mass) in the detection field, hence the name “volumetric detection”. The detection field has the form of a “tear”.
The detection technology of these sensors is based on the physics of the Doppler Effect.
The wavelenght of a signal reflected from a moving object is different than the wavelenght of the original signal.
The change – longer or shorter – in the wavelenght depends on the direction and speed of the moving object.
Some manufacturers base their technology on basic Doppler Effect calculations with one or two signals being emitted. This has its advantages and disadvantages, for example:
While a moving object can easily be detected in the field,it is impossible to get information on the distance from the sensor to the object. Without information about the distance from the sensor to the object it is hard to differentiate between the strenght of a signal generated by a small body (a little bird) closed to the sensor and a large object farther away from the sensor.
Our technology is based on Linear Frequency Modulation: the frequency of the emitted signal is changed in a predetermined range of steps. By comparing the characteristics of the bounced signals more information can be obtained about the range and velocity of the moving object making the detection in the field more accurate, thus making it possible to discriminate alarms generated by small or very large objects.
Advantages of Linear Frequency Modulation
Requirements and Tips for a successful installation: