# US 9,435,882 B2 · Method and apparatus for cognitive nonlinear radar > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,435,882 B2 - Document ID: US9435882B2 - Status: Granted - Kind: B2 - Application number: 14/010,580 - Filed: 2013-08-27 - Published: 2016-02-04 - Granted: 2016-09-06 - Earliest claimed: 2012-09-11 - Assignees: The United States of America as represented by the Secretary of the Army - Applicants: U.S. Army Research Laboratory ATTN: RDRL-LOC-I - Inventors: Anthony F. Martone; David M. McNamara; Gregory J. Mazzaro; Abigail S. Hedden - Web page: https://patentgrep.com/patent/US9435882B2 ## CPC - G01S 13/04: Systems determining presence of a target (based on relative movement of target G01S13/56) - G01S 7/021: {Auxiliary means for detecting or identifying radar signals or the like, e.g. radar jamming signals} - G01S 7/023: {Interference mitigation, e.g. reducing or avoiding non-intentional interference with other HF-transmitters, base station transmitters for mobile communication or other radar systems, e.g. using electro-magnetic interference [EMI] reduction techniques (auxiliary means for detecting or identifying radar signals or the like G01S7/021; means for anti-jamming G01S7/36)} - G01S 7/0232: {Avoidance by frequency multiplex} - G01S 7/0233: {Avoidance by phase multiplex} - G01S 7/28: Details of pulse systems - G01S 7/412: {based on a comparison between measured values and known or stored values} - G01S 7/414: {Discriminating targets with respect to background clutter} - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES ## Abstract A method and apparatus for cognitive non-linear radar processing comprising identifying one or more frequency bands of interest, passively scanning, using a non-linear radar (NR), the one or more frequency bands of interest to determine whether interference signals are occupying the one or more bands, transmitting radar waveforms and receiving radar waveform responses at one or more frequency bands determined to be free of interference, determining a likelihood of a target being present or not based on whether the received waveform responses match stored waveform responses for non-linear targets, and modifying waveform parameters of the transmitted radar waveform when the received waveform responses match the stored waveform responses, so as to transmit a modified radar waveform. ## Claims ### Claim 1 A method for cognitive non-linear radar processing comprising: identifying one or more frequency bands of interest; passively scanning, using a non-linear radar (NR), the one or more frequency bands of interest to determine whether interference signals are occupying the one or more bands; transmitting radar waveforms and receiving radar waveform responses in one or more frequency bands determined to be free of interference; determining a likelihood of a target being present or not based on whether the received waveform responses match stored waveform responses for non-linear targets; and modifying waveform parameters of the transmitted radar waveform when the received waveform responses match the stored waveform responses, so as to transmit a modified radar waveform. ### Claim 2 (depends on 1) The method of claim 1 further comprising: repeating passively scanning the one or more frequency bands of interest and transmitting modified radar waveforms until received waveforms do not match responses for non-linear targets. ### Claim 3 (depends on 1) The method of claim 1 wherein modifying the waveform parameters comprise: modifying one or more of frequency, amplitude, and phase of the transmitted radar waveform. ### Claim 4 (depends on 1) The method of claim 1 further comprising: receiving harmonic responses in response to the transmitted radar waveforms identifying non-linear targets. ### Claim 5 (depends on 1) The method of claim 1 further comprising: receiving intermodulation distortion product responses in response to the transmitted radar waveforms identifying non-linear targets. ### Claim 6 (depends on 1) The method of claim 1 wherein determining whether the received waveform responses match the stored waveform responses further comprises: measuring the likelihood that a target is present and determining that a target is present or not present based on a comparison between the likelihood and a predetermined threshold value. ### Claim 7 (depends on 6) The method of claim 6 further comprising: determining a signal to noise ratio (SNR) estimate for each of the received waveform responses; and determining the likelihood of detection for each feature of the SNR estimates. ### Claim 8 (depends on 7) The method of claim 7 further comprising:; classifying the each feature to identify a target type based on wave pattern templates. ### Claim 9 (depends on 8) The method of claim 8, wherein classifying further comprises: applying one or more of Bayesian discrimination functions, nearest neighbor classifying, support vector machines, neural networks, tree based algorithms and unsupervised learning methods. ### Claim 10 (depends on 9) The method of claim 9 further comprising: assigning a cost to a frequency associated with the classified feature; modifying the waveform parameters of the transmitted modified radar waveform based on the assigned cost; and transmitting the modified radar waveform at frequencies based on least cost to highest cost. ### Claim 11 (depends on 1) The method of claim 1 further comprising processing signals received by passively scanning, the processing further comprising: estimating signal to noise ratio of the received signals; and detecting potential communication targets and other RF signals. ### Claim 12 An apparatus for cognitive non-linear radar processing comprising: one or more passive receivers to scan one or more frequency bands of interest to determine whether interference signals are occupying the one or more bands of interest; a radar transmitter to transmit radar waveforms and receiving radar waveform responses in one or more frequency bands determined to be free of interference; and a cognitive processing module that determines the likelihood of a target being present or not based on whether the received waveform responses match stored waveform responses for non-linear targets and modifies waveform parameters of the transmitted radar waveform when the received waveform responses match the stored waveform responses, so as to transmit a modified waveform. ### Claim 13 (depends on 12) The apparatus of claim 12 further comprising: wherein the cognitive processing module reiterates passively scanning the one or more frequency bands of interest until received waveforms do not match responses for non-linear targets, identifying frequency sub-bands of interest which do not contain one or more of pre-existing signals and interference. ### Claim 14 (depends on 12) The apparatus of claim 12 wherein modifying the cognitive processing module further comprises a waveform module, wherein the waveform module modified the waveform parameters, and wherein the waveform parameters comprise one or more of frequency, amplitude, and phase of the transmitted waveform. ### Claim 15 (depends on 12) The apparatus of claim 12 wherein the apparatus receives harmonic responses in response to the transmitted radar waveforms identifying non-linear targets. ### Claim 16 (depends on 12) The apparatus of claim 12 wherein the apparatus receives intermodulation distortion product responses in response to the transmitted radar waveforms identifying non-linear targets. ### Claim 17 (depends on 12) The apparatus of claim 12 further wherein the cognitive processing module further comprises a classification module that determines whether the received waveform responses match the stored waveform responses further comprises: measuring the likelihood that a target is present and determining that a target is present or not present based on a comparison between the likelihood and a predetermined threshold value. ### Claim 18 (depends on 17) The apparatus of claim 17, wherein the cognitive processing module further comprises a signal to noise ratio module that estimates a signal to noise ratio (SNR) for each of the received waveform responses; and wherein the classification module further determines the likelihood of detection for each feature of the SNR estimates. ### Claim 19 (depends on 18) The apparatus of claim 18 further comprising wherein the classification module classifies the each feature to identify a target type based on wave pattern templates. ### Claim 20 (depends on 19) The apparatus of claim 19, wherein the classification module applies one or more of Bayesian discrimination functions, nearest neighbor classifying, support vector machines, neural networks, tree based algorithms and unsupervised learning methods to perform the classification. ### Claim 21 (depends on 20) The apparatus of claim 20 wherein the classification module further assigns a cost to a frequency associated with the classified feature, modifies the waveform parameters of the transmitted waveform based on the assigned cost; and transmits the modified radar waveform at frequencies based on least cost to highest cost. ### Claim 22 (depends on 12) The apparatus of claim 12 wherein the cognitive processing module further comprises a signal to noise ratio (SNR) module that estimates signal to noise ratio of the received signals and the one or more passive receivers detects potential communication targets and other RF signals.