A surface wave radar system including a receive antenna array (20, 22) for generating receive signals, and a data processing system (24) for processing received data representing the receive signals to mitigate ionospheric clutter. The received data is range and Doppler processed, and a spatial adap
A surface wave radar system including a receive antenna array (20, 22) for generating receive signals, and a data processing system (24) for processing received data representing the receive signals to mitigate ionospheric clutter. The received data is range and Doppler processed, and a spatial adaptive filter (52) is trained using training data selected from the processed data. The training data includes ionospheric clutter data and excludes cells which contain target data and substantial sea clutter. The processed data is filtered using the filter (52), which may be based on loaded sample matrix inversion. The antenna array (20,22) may be two-dimensional having an L or T shape.
대표청구항▼
The invention claimed is: 1. A surface wave radar system including: a receive antenna array for generating receive signals; and a data processing system for processing received data representing said receive signals to mitigate ionospheric clutter, wherein the ionospheric clutter is generated by ba
The invention claimed is: 1. A surface wave radar system including: a receive antenna array for generating receive signals; and a data processing system for processing received data representing said receive signals to mitigate ionospheric clutter, wherein the ionospheric clutter is generated by backscattering of transmit signals transmitted by the system. 2. A surface wave radar system as claimed in claim 1, wherein the processing of said data processing system includes filtering said received data on the basis of ionospheric clutter data generated from said received data. 3. A surface wave radar system as claimed in claim 2, wherein said data processing system includes an adaptive filter to perform said filtering, said filter being trained on the basis of said ionospheric clutter data generated by determining clutter estimates for selected cells of said received data. 4. A surface wave radar system as claimed in claim 3, wherein said data processing system includes a range and Doppler processor, a beamformer and detector for generating cells of processed radar data from said received data and generating said ionospheric clutter data, noise power data and probable target data for said cells, said ionospheric clutter data representing ionospheric clutter power, and said adaptive filter is trained using data of said cells having ionospheric clutter power above a noise threshold determined by said ionospheric clutter data and said noise power data, excluding data of cells identified by said probable target data and cells representing sea clutter. 5. A surface wave radar system as claimed in claim 4, wherein the processed radar data filtered by said adaptive filter is processed by said detector to generate probable target data. 6. A surface wave radar system as claimed in claim 5, wherein said filter is based on loaded sample matrix inversion. 7. A surface wave radar system as claimed in claim 6, wherein said filter executes where Yjl is a complex vector of said received data range-Doppler processed, Ω represents the training data, H denotes complex conjugation and transposition, j is a range bin number, l is a Doppler bin number, α is a loading factor, I is a diagonal unity matrix, and S(θ) is a steering vector corresponding to geometry of said array and a steering direction θ. 8. A surface wave radar system as claimed in claim 7, wherein said loaded sample matrix inversion is and a filter Wmj(θ) is shared by m consecutive range bins. 9. A surface wave radar system as claimed in claim 1, wherein said receive antenna array is a one-dimensional receive antenna array. 10. A surface wave radar system as claimed in claim 9, wherein said array includes a one dimensional broadside array of vertically polarised doublets, said broadside array being substantially perpendicular to a receiving direction of said antenna, and each of said doublets being substantially parallel to said receiving direction. 11. A surface wave radar system as claimed in claim 1, wherein said receive antenna array is a two-dimensional receiving antenna array. 12. A surface wave radar system as claimed in claim 11, wherein said array includes a one dimensional broadside array of vertically polarized doublets, said broadside array being substantially perpendicular to a receiving direction of said antenna, and each of said doublets being substantially parallel to said receiving direction, and an endfire array of vertically polarized antennas substantially perpendicular and adjacent to said broadside array. 13. A surface wave radar system as claimed in claim 12, wherein said array forms an L shape. 14. A surface wave radar system as claimed in claim 12, wherein said array forms a T shape. 15. A surface wave radar system as claimed in claim 12, wherein said endfire array includes one of monopoles and doublets, each of said doublets being substantially parallel to said receiving direction. 16. A method for processing range and Doppler processed data in a surface wave radar receiver, including, for each range, the steps of: training a spatial adaptive filter using training data of said processed data, said training data including ionospheric clutter data and excluding target data; and filtering said processed data using said filter. 17. A method as claimed in claim 16, including beamforming said processed data, and identifying said ionospheric clutter data and said target data by comparing the beamformed data with at least one threshold value. 18. A method as claimed in claim 17, wherein said training data excludes cells which contain substantial sea clutter. 19. A method as claimed in claim 18, wherein said filter is based on loaded sample matrix inversion. 20. A method as claimed in claim 19, wherein said filter executes where Yjl is a complex vector of said received data range-Doppler processed, Ω represents the training data, H denotes complex conjugation and transposition, j is a range bin number, l is a Doppler bin number, α is a loading factor, I is a diagonal unity matrix, and S(θ) is a steering vector corresponding to geometry of said array and a steering direction θ. 21. A method as claimed in claim 20, wherein said loaded sample matrix inversion is and a filter Wmj(θ) is shared by m consecutive range bins. 22. A surface wave radar system comprising: a transmitter operable to transmit high frequency signals; a receive antenna array operable to receive reflected versions of the transmitted high frequency signals and generate receive signals; and a data processing system operable to process the receive signals, wherein the processed receive signals are operable to remove ionospheric clutter received as part of the reflected versions of the transmitted high frequency signals.
Sishtla, Venkata A.; Robertson, Roy E.; Dana, Roger A.; Kronfeld, Kevin M.; Koenigs, Gregory J.; Finley, Jeffery A., Weather radar system and method for detecting a high altitude crystal cloud condition.
Dana, Roger A.; West, James B.; Kronfeld, Kevin M.; Koenigs, Gregory J.; Finley, Jeffery A.; Woodell, Daniel L., Weather radar system and method for detecting a high altitude crystal condition using two or more types of radar signals.
Breiholz, Arlen E.; Kronfeld, Kevin M.; Walling, Karen L.; McCabe, Robert J., Weather radar system and method with fusion of multiple weather information sources.
Breiholz, Arlen E.; Kronfeld, Kevin M.; Walling, Karen L., Weather radar system and method with latency compensation for data link weather information.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.