α	azimuth between the helicopter and the radar station [°]
β	elevation angle between the helicopter and the radar station [°]
A b	angle between adjacent blades of the rotor [°]
A r	rotor rotation angle [°]
c	propagation speed of electromagnetic waves [m/s]
D	distance between the helicopter and the radar station [m]
t	time[s]
m h	model of the helicopter
M f	triangular facet matrix of the model
s I	illuminated area
γ	rolling angle of the helicopter [°]
θ	pitching angle of the helicopter [°]
X r2	x axis coordinate of the tail rotor rotation axis
Z r2	z axis coordinate of the tail rotor rotation axis
σ	radar cross-section [dBm2]
t b	base transit time of the rotor blade [s]
ω r	angular velocity of the rotor [rad/s]
N b	number of rotor blades
Subscript
r1	main rotor
r2	tail rotor
fus	fuselage