针对全捷联半主动导引头大线性视场的要求; 分析了四象限光电系统线性视场与目标距离的关系。首先根据系统参数计算不同能见度、不同目标反射率下的目标距离与导引头接收光功率关系; 通过建立光学系统的仿真模型; 利用光线追迹方法获得不同视场对应的探测器光敏面光斑功率分布; 最后结合探测器灵敏度阈值; 得到线性视场与接收激光功率的关系：随着目标距离减小; 线性视场从0°增大到光学设计理论值。实验测试结果表明; 线性视场随着接收功率增大; 从0°增大到±9°; 与理论分析一致。因此; 全捷联半主动激光制导系统设计应该考虑导引头线性视场变化规律。

Considering the requirement on the wide linear field of the strapdown semi-active laser seeker, the relationship of linear field for four-quadrant detecting(QD) photoelectric system and target distance was analyzed. First, according to the system parameters, the relationship of target distance on different visibility, different target reflectivity and the received power for the laser seeker was calculated. Then by ray tracing method, the power distribution on quadrant detector for different field was found. Finally, the relationship of linear field and the received power was obtained. Linear field increased from zero to the theoretical value of optical design with the target distance decreasing. Experimental results indicate that linear field increases from 0° to ±9° with the received power increasing, which agrees well with the result of theoretic computation. The change law of the linear field should be considered for stapdown semi-active laser system design.