39results about How to "Achieve precise focus" patented technology

The invention discloses an imaging processing method for a coprime sampling satellite borne SAR, which belongs to the field of signal processing. The imaging processing method comprises the followingsteps: after obtaining imaging parameters, echo data and a coprime sampling matrix, firstly carrying out the range-wise pulse compression on a coprime sampling SAR echo signal, then starting from a first range gate, calculating the number of range gates spanned by the range gate echo signal according to Doppler parameters of each range gate, constructing a corresponding sparse dictionary, and intercepting a two-dimensional observation signal on the basis of the range gate echo signal, and finally reconstructing the two-dimensional observation signal by using an improved sparse reconstruction algorithm adaptive to the sparsity of the two-dimensional observation signal, thereby obtaining backscatter information of a scene target. By adopting the imaging processing method for the coprime sampling satellite borne SAR, the influence of the change of the imaging parameters along with the range door for the sparsity reconstruction can be compensated, the full-scene accurate focusing can be realized, the imaging processing under a coprime sampling working mode can be realized, the imaging accuracy is high, and the practicability is high.

The invention discloses a high squint SAR curvilinear path wavenumber domain imaging method based on a slope distance model, comprising: building a high squint SAR (Synthetic Aperture Radar) geometric model on a curvilinear path, selecting any point target Q, successively calculating an instantaneous slant distance R (ta) from an SAR aircraft to the point target Q, and a hyperbola instantaneous slant distance Re(ta) from the SAR aircraft to the point target Q, furthermore calculating the instantaneous slant distance R (X) from a high squint SAR aircraft on a curvilinear path to a point target, calculating distance frequency domain orientation time domain echo signals S (Kr, X) of a high squint SAR on a curvilinear path, furthermore successively calculating orientation time domain echo signals S<^> (Kr, X) of a high squint SAR on a curvilinear path after distance pulse pressure, and orientation time domain echo signals S (Kr, Kx) of a high squint SAR on a curvilinear path after fast fourier transform (FFT), setting an orientation resampling coefficient Kx-new, calculating orientation time domain echo signals S (Kr, Kx-new) of a high squint SAR on a curvilinear path after orientation resampling, furthermore calculating echo signals of a high squint SAR on a curvilinear path under a two-dimensional beam spectrum, successively performing range direction IFFT and azimuth IFFT, and obtaining high squint SAR imaging under a slope distance model.