| 摘要 |
A corner reflector lined with resonant frequency determining hollow gas-filled spheres is interrogated with a plurality of frequencies, including the resonant frequency and the acoustic return is substantially only the resonant frequency. A four-quadrant device is provided and each quadrant of the device is lined with different sized spheres for four different resonant frequencies, and installed according to predetermined geographical coordinates and orientation. With the combination of resonant frequencies, the interrogating vessel can obtain directional as well as identifying information with respect to the device.
|
