Abstract: The present invention describes a method and device to use radar to measure vibrations of a target object. The invention employs a radar system in which a signal equivalent to an echo from the object when it is not vibrating is subtracted from the actual returning echo signal before that echo signal is detected by the system's receiver so that the signal then actually received by the receiver consists only of that very much smaller component of the echo which is due to the displacements of the vibrating object from its rest position. This echo component is then amplified, and displacements of the object are determined from the amplified signal. The present invention utilizes long wavelength radar signals that can penetrate the ground to buried pipes and objects and permits detection of the effects of vibration on the reflected signals that are unmeasurable by known means. The present invention allows detection of vibrations of an object without making physical contact with it.