Virtual noise radar waveform for reduced radar detectability
First Claim
1. Apparatus for generating a radar waveform comprising:
- generation means for generating a series of pulses in a pseudo-random pattern and for combining said pulses to produce an offset frequency signal;
carrier means for generating a carrier wave having a frequency within a predetermined band of frequencies;
means for modulating said carrier wave with said offset frequency signal;
means for suppressing the characteristics of the resulting modulated waveform; and
,propagation means for transmitting said resulting waveform and for receiving a return waveform, said transmitted waveform having no discernible attributes by which said waveform, if received and analyzed by a detection means other than said propagation means, would convey any intelligence as to the presence of the transmitted waveform or the source thereof.
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Accused Products
Abstract
Apparatus (10) for generating a radar waveform (W). A noise generator (20) generates a series of pulses in a pseudo-random pattern, and a frequency generator (16) generates a carrier wave having a frequency within a predetermined band of frequencies. The carrier wave is modulated with the pseudo-random pattern of pulses, and the resulting modulated carrier wave passed through both a filter (30) and an attenuator (32) to suppress any discernible feature or signal characteristics of the resulting waveform. The modulated carrier is transmitted by an antenna (42) and a received return signal is processed by a signal processor (100) to obtain pertinent information about a target. The transmitted waveform has no discernible attributes by which the waveform, if processed and analyzed by someone else'"'"'s radar detector (E) would convey any intelligence as to the presence or source of the transmitted waveform.
41 Citations
32 Claims
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1. Apparatus for generating a radar waveform comprising:
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generation means for generating a series of pulses in a pseudo-random pattern and for combining said pulses to produce an offset frequency signal; carrier means for generating a carrier wave having a frequency within a predetermined band of frequencies; means for modulating said carrier wave with said offset frequency signal; means for suppressing the characteristics of the resulting modulated waveform; and
,propagation means for transmitting said resulting waveform and for receiving a return waveform, said transmitted waveform having no discernible attributes by which said waveform, if received and analyzed by a detection means other than said propagation means, would convey any intelligence as to the presence of the transmitted waveform or the source thereof. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. Apparatus for generating a virtual noise waveform comprising:
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generation means for generating a series of coded digital electrical pulses in a pseudo-random pattern; means for modulating a carrier wave with the pulses to produce a modulated waveform; means filtering the resulting modulated waveform for an output waveform from the filter to fall within a null portion of the filter for the waveform energy of the output from the filter to be at a minimum level, the bandwidth of the filtered waveform being sufficient to enable the waveform to obtain desired information when directed at an area of interest; and
,attenuation means attenuating the filtered waveform to sufficiently suppress any remaining features of the waveform so to produce a virtual noise waveform which will appear as a random noise signal having no discernible attributes and conveying no information about the waveform or its source. - View Dependent Claims (16, 17, 18, 19, 20)
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21. A method of generating a virtual noise waveform comprising:
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generating a first and a second series of digital pulses in a pseudo-random pattern; combining said respective series of pulses to produce an offset frequency; modulating a carrier wave with the offset frequency to produce a modulated waveform; and
, suppressing the characteristics of the resulting modulated waveform for the waveform to have no discernible attributes which would convey any information about the existence of the waveform or its source. - View Dependent Claims (22, 23, 24, 25, 26, 27)
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28. A method of generating a radar waveform comprising:
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generating an in-phase series and a quadrature-phase series of coded pulse sequences in a pseudo-random pattern; combining the two series of coded pulse sequences into an offset frequency; generating a carrier wave having a frequency within a predetermined frequency band; modulating said carrier wave with said offset frequency; filtering the modulated waveform so the waveform energy is concentrated within a narrow bandwidth corresponding to the bandwidth required for information gathering, the energy of the resulting filtered waveform being substantially less than that of the unfiltered modulated waveform; attenuating the filtered waveform to suppress any features therein and to eliminate any discernible features of the filtered waveform; and
,transmitting the resulting waveform and receiving a return waveform, said transmitted waveform, if received and analyzed by a detection means other than that associated with the source of the waveform, appearing as a random noise signal having no discernible attributes and conveying no information about the waveform or its source. - View Dependent Claims (29, 30, 31, 32)
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Specification