Three-Dimensional Impact-Angle Control with Biased Proportional Navigation

An impact-angle guidance law for three-dimensional engagements is presented in this paper. The guidance law is derived without linearization, takes the cross-coupling effects into account, and does not require the time-to-go information. The approach is based on plane pursuit, which aims to bring the velocity vector of the missile into a rotating impact plane, and biased proportional navigation, in which the bias is applied only over the initial part of the engagement. The proposed guidance law is in stand-alone vector form and straightforward to implement. The performance is demonstrated with simulation runs.