The airborne synthetic aperture radar（SAR） system realizes the large azimuth width by scanning. The scanning angular velocity is restricted by azimuth resolution， squint angle and other parameters. It is a difficult problem to design and implement airborne wide-width azimuth scanning SAR with both scanning efficiency and azimuth resolution. In order to realize azimuth wide-swath scanning in the air route， a beam control method is proposed. By deriving the scanning angle change rule between different scene images， and designing the start scanning angle and end scanning angle of each scene image according to the angle change rule， the designed beam control method can meet the resolution requirements of the scanning angle velocity of each scene image and has a time-varying angular velocity with a high scanning efficiency. Overlapping between scenes to ensure coverage and the target scene is located in the middle of the scanning width in the course.

From the perspective of active and passive radar target tracking data fusion， this paper summarizes the measurement error distribution characteristics of discrete space distributed active and passive radars for the same air target through a qualitative analysis method of radar measurement error combing mathematical approximation processing and geometric figure analysis. A novel fusion method for active and passive radar target measurement data is proposed when the angle between the target and the deployment point of the active and passive radar is small. By optimizing the weighting coefficient allocation criteria to fully combine the advantages of the each radar measurement accuracy， the target tracking data is fused in the geosphere coordinate system to improve measurement accuracy， the target fusion data is smoothed using the extended Kalman filter algorithm. The simulation results show that this method can combine the advantages of active and passive radar target measurement accuracy， reduce the measurement error ellipse after target data fusion， and overall improve the measurement accuracy of fused target tracking data.

In April 2021， the U.S. Air Force Doctrine Development and Education Center officially released “Air Force Doctrine Publication 1： The Air Force” （AFDP-1） （March 10， 2021 Edition）， completing a major update to the Air Force Basic Doctrine Volumes 1 and 2， which serve as the most fundamental doctrine of the U.S. Air Force and will guide the combat operation for a long time. In the updated AFDP-1 doctrine， it is clearly stated that the mission-based command should be regarded as the basic concept of the air force command and control， and the traditional principle of "centralized control and decentralized execution" should be replaced by "centralized command， distributed control and decentralized execution"， in order to accommodate the continuous evolution of operational concept， system architecture and equipment form， and lay the foundation for gaining advantages in major power competition and strong enemy confrontation. In view of such significant changes in the fundamental doctrine， this paper will conduct an in-depth analysis from the aspects of background and motivations， principles and implementation of mission-based command， and its relationship with traditional command paradigm， and gain the insight into the connotation behind such transformation. This paper summarizes the enlightenment and significance brought by this change， which will provide a reference for the future development planning.

Aiming at the common current loop， speed loop and position loop control structure of dual-motor synchronous anti-backlash servo system， a simplified control strategy with stronger robustness and faster response speed is proposed. The positon controller of the servo system is designed based on the backstepping theory and the torque reference command is directly calculated and transmitted to the current loop from the reference position command after command-filter processing, which simplifies the control structure. The integral nonsingular terminal sliding surface is introduced in the backstepping controller design process which overcomes the chattering problem of the linear sliding mode control and makes the system reach the equilibrium state in finite time. The extended state observer （ESO） is adopted to compensate the external disturbance which makes the servo system more robust to the changes of the internal structure parameters and external disturbance torque. The co-simulation experiment is carried out in Matlab/Simulink and Adams and the results show that the proposed new dual-motor synchronous anti-backlash method has better tracking performance than tradition scheme and better anti-disturbance ability than the ordinary disturbance compensation method.

In order to avoid the tedious parameter tuning process， a self-tuning and optimization method for the speed loop controller parameters based on inertia identification is proposed. The design rules of the speed loop controller parameters are analyzed with the frequency method. The inertia is identified with recursive least square method with a forgetting factor. The controller parameters optimization is performed using the variable step iterative algorithm designed in this paper. Simulation results show that using the recursive least square method with a forgetting factor can effectively identify the moment of the inertia of a motor. Speed loop controller parameters， which are optimized by the method proposed， can provide the system good dynamic response and robustness.