Aiming at the problem of low recognition accuracy due to the increasing complexity of aircraft flight movements in air combat， this paper proposes an air combat flight situation recognition method based on enhanced support vector regression. The sparrow search algorithm is improved by using pinhole imaging and chaos initialization. The improved sparrow algorithm is used to optimize the support vector regression algorithm， which is specifically represented by the optimisation of the parameters of the Gaussian kernel function in the support vector regression algorithm. The optimized support vector regression algorithm is used to identify aircraft movements.Five basic flight actions and complex flight actions are used to verify the recognition accuracy of the method. Simulation shows that the optimised support vector regression algorithm improves the average recognition rate of basic flight manoeuvres by at least 2.2%， and the average recognition rate of complex flight action by at least 3.7%， compared with the traditional support vector regression algorithm， fuzzy support vector machine algorithm， traditional clustering algorithm， and neural network algorithm.

With the continuous development and evolution of the concept of navigation warfare， the United States continues to promote the construction of navigation countermeasure systems and the transformation of command systems， seeking asymmetric advantages of positioning， navigation， and timing （PNT） information. The development of the U.S. navigation countermeasure system is studied from the aspects of command function system construction， navigation countermeasure ability improvement， exercise and training foundation construction， and actual navigation countermeasure combat. The offensive and defensive countermeasure capabilities based on the satellite navigation system are analyzed. While accelerating the construction of the GPS-based PNT system， the United States has continuously combined serial exercises and actual combat operations to enhance the offensive and defensive capabilities of navigation warfare， which should arouse great attention of China.

As one of the missile thrust vector substitution control schemes， the gas rudder operates in a very complex high-temperature gas environment. It is difficult to accurately predict the surface force and thermal load of the gas rudder and predict its ablation. At home and abroad， relevant researches have been carried out on the aerodynamic characteristics and related thermal environment of gas rudders through experiments and numerical calculations， which proves the feasibility and accuracy of predicting and simulating gas rudder ablation by numerical method， and provides strong support for the subsequent design and optimization of gas rudder in engineering practice.