Patents
An equipment which can detect a person buried under rubble or behind a barrier is described. The equipment has been built on the principle of backscattering of electromagnetic waves by the body of an animate subject, which when illuminated by a radio beam of suitable frequency, a part of the electromagnetic energy is backscattered and it travels up the rubble where it is picked up by the antenna at the top of the rubble. The signal so picked up carries the Doppler modulation in phase and amplitude due to the movement of the chest region/body movement. The signal is processed by a receiver. The receiver displays either the periodic breathing cycles and/or sudden changes in steady level of signal as the case may be, to indicate the presence of the trapped animate subject under the rubble.