针对半实物仿真中定向红外对抗系统的有效模拟问题，在分析定向红外对抗激光源技术的基础上，依据实战应用，计算得到3 μm~5 μm波段定向红外对抗激光源的辐射能量为飞机红外辐射强度绝对值的8倍，结合波长4 μm处简化的大气传输透过率随传输距离的变化，推导出实战应用中红外导引头上辐射照度随飞机导弹之间距离的变化规律。设计半实物仿真中定向红外对抗的模拟方案，依据逼真模拟的原则，计算得到模拟激光源能量随飞机导弹之间距离和飞机辐射强度的变化规律，据此将飞机导弹相互距离1 km时刻的红外干扰源辐射能量设置为波长4 μm模拟激光源能量，其他距离的模拟能量通过衰减片来控制。为提高定向红外对抗模拟的通用性和智能性，设计了模拟激光源的闭环控制方案。

Aiming at the effective simulation of the DIRCM in the hardware-in-the-loop simulation, the calculated radiation energy for the laser source is 8 times of the absolute value of the aircraft radiation intensity in the band range of 3 μm~5 μm based on the analysis of the laser source in DIRCM and real battlefield scenario. Combined with the change of atmospheric transmission transmittance in 4 μm, the change rule of radiance on the IR seeker is obtained with the change of distance between the aircraft and the missile. The simulation scheme of DIRCM in the hardware-in-the-loop simulation is designed based on the principle of realistic simulation, the energy change of the laser source is calculated with the change of distance between the aircraft and the missile, the energy of IR interference radiation energy in 1 km is set as the energy of the simulation laser source, and the energies in other distances are controlled through the attenuation slice. At last, for the purpose of improving the versatility and intelligence in DIRCM simulation, the closed loop control of simulation laser is designed, and the method of closed loop control for interference wavelength and modulation mode is studied.