介绍了红外侦察预警系统被动测距的原理，探讨了双站布设距离及三站布阵方式对测距精度的影响，提出了三站联合测距的最优布设方式-等边三角形布阵，分析了该种布阵对目标的测距精度。仿真结果表明，该布阵方式可最大限度地降低目标距离的误报率，且能兼顾0 °～360 °范围测距的精度和一致性；1 km的站点间距可保证14.2 km距离内目标的测距精度优于10%，大大提高了三站联合测距的效果。

The passive ranging principle of an infrared reconnaissance warning system is presented. The influence of bi-station distance and tri-station mode on ranging accuracy is discussed. An equilateral triangle disposal-optimal layout method for three joint station ranging is proposed. Its ranging accuracy for the target to be measured is analyzed. The simulation results show that the method can minimize the false alarm rate of target distance with the balance of the ranging accuracy in the range from 0 degree to 360 degree and the consistency. The site spacing of 1 km can ensure the location accuracy of the target to be better than 10% in the distance of 14.2 km. Thus, the three joint station ranging effectiveness can be improved greatly.