METHOD OF HELICOPTERS DETECTION BY ONBOARD RADAR STATION Russian patent published in 2019 - IPC G01S13/52 

FIELD: radar ranging and radio navigation.

SUBSTANCE: invention relates to radar ranging and can be used in aircraft onboard radar stations (ORS) to detect a flying or hovering helicopter on the background of an underlying surface. Technical result is achieved due to the fact that during scanning in a given viewing sector with a beam of the antenna radiation pattern (ARP), a pulsed signal is coherently emitted, receiving a pulse signal reflected from the earth's surface by two independent ARP beams at azimuth spaced apart, signals received on each ARP beam are strobed along the range, performing their analogue-to-digital conversion, coherently accumulating in the entire field of view, forming two arrays of signal readings, determining the steepness of frequency modulation of accumulated signals, determining and compensating for time delay between signals received for each independent beam reflected from the same portion of the earth's surface simultaneously with eliminating frequency modulation of signals, by heterodyning, converting compensated signal arrays into a frequency domain, determining phase difference between frequency-converted signal arrays for all frequencies and range strobe, calculating a phase difference threshold across all readings of signal arrays, comparing phase difference values for all frequencies and range gates with a threshold value, when the phase difference of the threshold value is exceeded, recording the presence of the moving target in the signal reading at the corresponding frequency and in the corresponding range strobe, when a group moving target is detected in one strobe with the same frequency pitch between separate moving targets, the frequency pitch value is recorded, the above operations of N cycles are repeated, where N is an integer greater than one, upon detecting a group moving target in one range strobe and matching the step size by frequency between separate moving targets in all N cycles, the detected group moving target is considered to be a helicopter.

EFFECT: high probability of detecting helicopters on background of underlying surface.

5 cl, 5 dwg