Method and apparatus for the detection of objects using electromagnetic wave attenuation patterns
OwnerJames L. Geerinventor
Life of this patent
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Abstract
A method for detecting an object, comprising the steps of defining expected characteristics of scattered electromagnetic radiation to be received at a receiver; attenuating at least a portion of electromagnetic radiation received at the receiver by a presence of an object within a path of electromagnetic information; and detecting the attenuation to indicate a presence of the object. The object may be a low radar profile object, such as a stealth aircraft. The electromagnetic radiation is preferably microwave, but may also be radio frequency or infrared. By using triangulation and other geometric techniques, distance and position of the object may be computed.
Claims20
A method for processing a signal, comprising:
- transmitting modulated radio frequency electromagnetic radiation propagating along at least one off axis path with respect to a receiver toward a scattering medium;
- scattering the modulated radio frequency electromagnetic radiation with the scattering medium;
- receiving the scattered modulated radio frequency electromagnetic radiation at the receiver, wherein the receiver has a plurality of receiving antennas, each receiving a respective distinct scattered modulated radio frequency electromagnetic radiation signal;
- determining a respective time delay associated with the received scattered modulated radio frequency electromagnetic radiation signals with at least one correlator;
- and
- determining expected characteristics of the respective scattered modulated radio frequency electromagnetic radiation signals at the receiver.
A method for distinguishing scattered radiation, comprising:
- transmitting at least one coherent modulated radio frequency electromagnetic radiation signal, propagating along at least one off axis path with respect to a receiver having a plurality of antennas, toward a scattering medium;
- scattering the at least one coherent modulated radio frequency electromagnetic radiation signal with the scattering medium;
- receiving a plurality of modulated scattered radio frequency electromagnetic radiation signals through the plurality of antennas, each receiving antenna receiving a distinct scattered radio frequency modulated electromagnetic radiation signal, derived from the at least one coherent modulated radio frequency electromagnetic radiation signal, at the receiver;
- correlating the plurality of received modulated scattered radio frequency electromagnetic radiation signals to determine at least one time delay associated with the received plurality of modulated scattered radio frequency electromagnetic radiation signals;
- and
- determining expected characteristics of the plurality of modulated scattered radio frequency electromagnetic radiation signals at the receiver.
A receiver for processing a signal, comprising:
- plurality of receiving antennas, each receiving antenna being configured to receive a distinct scattered modulated radio frequency electromagnetic radiation signal propagating off-axis with respect to a source of the modulated radio frequency electromagnetic radiation, from a scattering medium;
- an input configured to receive an output from each respective antenna corresponding to the distinct scattered modulated radio frequency electromagnetic radiation signals;
- and
- at least one processor configured to correlate at least two outputs from respective antennas to estimate a time delay associated with the received scattered modulated radio frequency electromagnetic radiation represented in the outputs from the respective antennas, to determine expected characteristics of the scattered modulated radio frequency electromagnetic radiation.
Dependencies are inferred from the claim text.