US 12,282,082 B2
Method and apparatus for detecting breathing radar targets
John C. Dougherty, Liverpool, NY (US)
Assigned to SRC, Inc., North Syracuse, NY (US)
Filed by SRC, Inc., North Syracuse, NY (US)
Filed on Jan. 10, 2022, as Appl. No. 17/571,698.
Prior Publication US 2023/0221426 A1, Jul. 13, 2023
Int. Cl. G01S 13/56 (2006.01); G01S 7/41 (2006.01)
CPC G01S 13/56 (2013.01) [G01S 7/418 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A computer-implemented method comprising:
separating an electric signal generated by Doppler processors of a radar into alternating current (AC) magnitudes with Doppler frequencies corresponding to absolute values between 0.1 and 4 Hz and direct current (DC) magnitudes with no Doppler frequency;
generating an AC line by calculating a sum of the AC magnitudes across Doppler cells for one or more range cells and by running constant false alarm rate (CFAR) detector algorithm for the sum of the AC magnitudes;
generating a DC line by calculating a sum of the DC magnitudes across the Doppler cells for each range cell and by running CFAR detector algorithm for the sum of the DC magnitudes;
comparing an energy level difference between an energy spike in the AC line and another energy spike in the DC line with a threshold set for detecting a breathing target that is stationary; and
based on ascertaining that the energy level difference between the energy spikes respective to the AC line and the DC line is greater than the threshold, detecting the breathing target that is stationary and generating an output that informs a user operator of the radar on the breathing target with a range value of the breathing target from the radar.