METHOD OF FORMING RADAR IMAGES Russian patent published in 2016 - IPC G01S13/00 

FIELD: radio engineering, communication.

SUBSTANCE: method of forming a radar image comprises compensating for linear spatial distortion of images at the ascending and descending portion of variation of a chirp signal and additional image focusing, which takes into account the broadband properties of linear frequency modulation. To this end, after the procedure of receiving and recording into memory echo signals reflected from all objects in the coverage area of synthetic-aperture radar, data containing echo signal readings on the ascending and descending portions of variation of frequency of the probing chirp signal are divided. Parallel compression of said data on range and calculation of a phase distortion error estimate during autofocusing is then performed. At the step of compressing data on the azimuth, a pair of radar images is formed, wherein reference functions differing from each other by carrier frequencies for the ascending and descending portions of variation of frequency of the chirp signal are formed. The next step includes consecutive calculation of the cross-correlation coefficient of said radar images at different values of the linear sampling error of echo signals according to a "golden section" algorithm. Based on the calculated estimate of said error, additional focusing is performed for each image, and after geometric correction of the pair of radar images in order to bring said images to a single scale, incoherent summation of said images is performed.

EFFECT: high probability of correct recognition of small-size and distributed objects on an area.

1 dwg