Development and modeling of algorithms for calculating target angle in the coordinate system of the onboard radar

The article is devoted to the development of algorithms for calculating the target angle in the coordinate system of an onboard radar and modeling their operation. To construct an algorithm for calculating the target angle, a fixed terrestrial coordinate system and a moving coordinate system of an onboard radar are used. Expressions are presented for recalculating the Cartesian coordinates of an object from the earth coordinate system to the on-board radar coordinate system. The concept of azimuth and elevation planes is introduced for the coordinate system of an onboard radar. Algorithms for calculating target angles in the azimuthal and elevation planes are presented. It is shown that the algorithm for calculating the target angle in the elevation plane has a different form depending on the sign of the target elevation angle. In addition, the type of the mentioned algorithm depends on whether the target is approaching or moving away from the onboard radar. The resulting algorithms for calculating the target angle use information about the coordinates of the target speed in the coordinate system of the onboard radar. Since the coordinates of the velocity vector in the onboard radar cannot be measured, they are estimated from two contacts with the target during the review period. Modeling of the developed algorithms has been carried out.