| 摘要 |
<p>A system for detecting a change in position of at least one object within an at least partially enclosed space, the system including at least one transmitter repeatedly producing at least two mutually distinguishable standing waves in the at least partially enclosed space at mutually exclusive and mutually alternating times, at least one receiver receiving reflected energy of the at least two mutually distinguishable standing waves, the reflected energy from the at least two mutually distinguishable standing waves having mutually different amplitudes which have a difference therebetween, and a computerized processor receiving outputs from the at least one receiver and calculating changes in the difference between the mutually different amplitudes, which changes indicate the change in position of the at least one object.</p> |
