Squinted multi-channel SAR phase error estimation method based on subspace orthogonality

Abstract

The application discloses a squint multi-channel SAR phase error estimation method based on a subspace, and comprises the following steps: data recombination is performed on squint multi-channel SAR echo data; azimuth fast Fourier transform is performed on echo data of each channel, and signals are transformed from two-dimensional time domain to a range Doppler domain; in the range Doppler domain, the covariance matrix of each channel data at each Doppler frequency point is calculated; the covariance matrix is subjected to eigenvalue decomposition, and the obtained eigenvalues are sorted from large to small; a signal subspace, a noise subspace, a steering vector, and a subspace formed by the steering vector are calculated; the inter-channel phase error at each Doppler frequency unit is estimated; and the Doppler frequency unit corresponding to an effective phase error estimation result is selected. The application can effectively estimate the phase error of squint multi-channel SAR.

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