High-efficiency time reversal imaging method

The invention discloses a high-efficiency time reversal imaging method. An ultra-wideband antenna array collects time-domain signals scattered by a non-cooperative object, the time-domain signals are converted into frequency-domain signals via Fourier transform, a frequency-domain space-frequency multi-mode response matrix is established, and the frequency-domain space-frequency multi-mode response matrix is decomposed by singular values to obtain signal subspace and noise subspace vectors; and selective focusing imaging of the object is realized by taking one selected from a position 1) where an inner product of the signal subspace vector and a background green function vector corresponding to an infield point of a detection area is maximal and a position 2) where a conjugate inner product where the noise subspace vector and the background green function vector corresponding to the infield point of the detection area is 0 as a focusing imaging position of the object. Via the method, it is required that the a