中文摘要：

针对天幕靶探测弹丸的可靠性问题,介绍了一种分析与计算天幕靶探测灵敏度和捕获率的方法。根据天幕靶的工作原理,从探测光幕的幕厚、弹丸长度和光电探测器等方面分析了其光学探测性能;研究了弹丸尺寸、光学镜头参数和探测灵敏度与捕获率的关系,给出它们之间的计算方法。将弹丸在光电探测器感光面上的成像光斑分解为多个单元面积,计算了弹丸穿越光幕过程中探测电路输出的信号;根据瞬间输出信号与背景噪声信号相比较来判断弹丸的存在,并分析了天幕靶的捕获率和影响因素。在大于500 lx的光照度下,按照公式计算了天幕靶探测灵敏度与捕获率,结果表明：当弹丸长度大于光幕幕厚时,天幕靶捕获率为100%;当弹丸长度小于光幕幕厚时,在极端探测距离条件下,捕获率明显降低。

英文摘要：

Aiming at the dependability of sky-screen,a new method was introduced on analyzing and calculating its detection sensitivity and acquirement rate.According to the working principle of sky-screen,from the screen thickness,projectile length and detector,its detection optical performances were analyzed.The relation on projectile size,optical lens parameters,detection sensitivity and acquirement rate were studied and their calculation expressions were advanced.The image facula of projectile was divided into many small unit areas to calculate the output signal value of detection circuit when projectile traversing the detection screen.The real projectile information was identified by comparing the output signal value between projectile image information and background noise in detection circuit,and its influence factors were analyzed.When the illumination was more than 500 lx,the sensitivity and acquirement rate were calculated by its calculation expression.The result shows that the acquirement rate is 100% when the length of projectile is more than the thickness of sky-screen,and the acquirement rate decreased significantly when the length of projectile is less than the thickness of sky-screen.