The problem that two cooperative missiles intercept a maneuvering target while imposing a desired relative geometry is investigated in the paper. Firstly, a three-dimensional (3D) estimation model for cooperative target tracking is proposed and the observability of the missile-target range measurement is analyzed. In order to enhance the estimation performance, a two-level cooperative interception guidance architecture is proposed which combines a coordination algorithm with a novel 3D fixed-time convergent guidance law considering line of sight (LOS) angle constraints, such that the desired relative geometry can be imposed quickly and steadily by a dynamic strategy. The effectiveness and superiority of the proposed guidance law is evidenced through the numerical simulations comparing with other guidance laws.

Fast and accurate threat evaluation (TE) of incoming air targets has a great influence on air defense. In this paper, two new generalized intuitionistic fuzzy soft set (GIFSS) methods are proposed for threat evaluation of air targets. Firstly, the threat evaluation index system is reasonably constructed by analyzing the relative kinematics between the targets and assets, apart from that between the targets and interceptors, which is more reasonable and practical. Secondly, after the threat indexes (TI) are properly obtained, two new aggregation operators for GIFSS are put forward based on the generalized $\lambda$-Shapley Choquet integral. The proposed operators not only depict the correlations among the evaluation index but also consider the importance of them globally. Finally, the effectiveness and superiority of the proposed methods are verified through a numerical simulation including four air targets in different index systems.

Rapid and accurate threat evaluation(TE) of incoming targets is the key part in air defense. In order to evaluate the target threat effectively, a threat evaluation index system is constructed. On this basis, an improved kernel principal component analysis method (KPCA) based on hybrid kernel function is proposed to realize dimension reduction of the index data, particle swarm optimization (PSO) is utilized to optimize the parameters. The threat of targets is evaluated and ranked by the technique for order of reference by similarity to ideal solution method (TOPSIS) with the variance contributions of kernel principal components for weighing the processed data. The proposed method can avoid the subjectivity introduced by traditional methods and make dimension reduction of evaluation index data, thus decreasing the complexity of evaluation and improving real-time performance. The numerical experiment shows that the results obtained by this method are reasonable and realistic.

The problem of integrated guidance and control for missiles against maneuvering target was studied in this paper. Integrated guidance and control model of pitch plane was established on a roll stable missile. The target maneuver was considered as unknown bounded uncertainty. An adaptive integrated guidance and control law was designed by adopting sliding mode control to deal with the uncertainty. The adaptability and robustness were achieved by choosing zero effort miss as the sliding mode surface. The simulation result demonstrates that the integrated guidance and control system can meet the accuracy requirement of hitting the maneuvering target with terminal impact angle constraint.

Aiming at the successful handover for seeker in the course of midcourse to terminal guidance handover, a model of the probability of target acquistion containing the radar error is proposed and an optimal midcourse guidance law to enhance the probability is designed. Simulation results show that the guidance law proposed can effectively reduce the velocity deflection angle and enhance the probility of target acquistion while intercepting big maneuvering target.