A Method for Synthesis of Frequency-Time Radio Images in Non-Radiating Radars

We propose a modification of the known method used to synthesize frequency time radio images in non-radiating radars and based on minimization of the r.m.s. deviation of the observation data vector from its linear model with an additional limitation imposed on the L1 norm of the vector of the evaluated amplitudes of two-dimensional signal distribution in the range of delays and Doppler frequencies. The essence of the modification is that instead of solving the problem of conditional minimization at a full array in the “time delay—Doppler frequency shift” coordinates, this problem is solved sequentially for the zeroth and a preset frequency shift. In combination with additional computational tricks, the proposed modification allows one to increase the computational efficiency of image formation by three orders of magnitude.