Calculation trajectories of stealthy movement of aircraft to a specified point in detection zone of onboard Doppler radar

An onboard radar operating in the impulse–Doppler mode has the characteristic features of the detection zone. The feature lies in the fact that at every point of the detection zone an aircraft has a sector of directions such as the onboard Doppler radar will not detect it as long as it moves in these directions. This sector is called the sector of invisible motion directions of the aircraft. Because of these features, there are such trajectories that aircraft flying along them are not detected by an onboard Doppler radar, such as an AWACS radar. The article proposes a method for planning stealthy trajectories between two given points in the Doppler radar coverage area. Trajectories are selected from a parametric family of elliptical stealthy trajectories, which are ellipses in the AWACS-associated moving coordinate system. An equation is found for the characteristic parameter of the ellipse, the solution of which allows us to uniquely identify the stealthy trajectory between two given points. The conditions for the existence of stealthy trajectories passing through specified points are investigated.