Related Experiment Video
Updated: May 28, 2026

Time Multiplexing Super Resolving Technique for Imaging from a Moving Platform
Published on: February 12, 2014
Two applications of time reversal mirrors: seismic radio and seismic radar
Sherif M Hanafy1, Gerard T Schuster
1King Abdullah University of Science and Technology (KAUST), Thuwal, Jeddah 23955, Saudi Arabia. sherif.geo@gmail.com
Abstract:
Two seismic applications of time reversal mirrors (TRMs) are introduced and tested with field experiments. The first one is sending, receiving, and decoding coded messages similar to a radio except seismic waves are used. The second one is, similar to radar surveillance, detecting and tracking a moving object(s) in a remote area, including the determination of the objects speed of movement. Both applications require the prior recording of calibration Green's functions in the area of interest. This reference Green's function will be used as a codebook to decrypt the coded message in the first application and as a moving sensor for the second application. Field tests show that seismic radar can detect the moving coordinates (x(t), y(t), z(t)) of a person running through a calibration site. This information also allows for a calculation of his velocity as a function of location. Results with the seismic radio are successful in seismically detecting and decoding coded pulses produced by a hammer. Both seismic radio and radar are highly robust to signals in high noise environments due to the super-stacking property of TRMs.
More Related Videos
Related Concept Videos
Basic Operations on Signals
Time Reversal mirrors a continuous-time signal about the vertical axis at t=0. This is achieved by substituting t with −t. For example, if a signal x(t) is considered, the time-reversed signal is x(−t). This operation can be graphically represented, showing the mirrored signal.
Doppler Effect - II
Echo
Imagine the sound is reflected back to the ears. Assuming that the source is very close to the human, the difference between hearing the two sounds—the emitted sound and the reflected sound—may be more than the minimum time for perceiving distinct sounds. If this is the case, then the...
Properties of Fourier series I
Properties of Fourier Transform I
In radio broadcasting, multiple audio signals often need to be transmitted simultaneously. The Fourier...
Field Application of Global Positioning System

