超低空飞行的飞航导弹、无人驾驶飞机,特别是远程巡航导弹,无论是在海面上空,还是在陆地上空飞行,为了增加飞行器的突防能力,都将尽量压低飞行高度,进行所谓“掠海”或“擦树稍”飞行。对于击水概率或碰地概率的研究是上述飞行器设计中重要课题之一。本文推导了地形跟踪导弹碰地概率的一个计算公式,并将其与以往通常使用的公式进行了比较。 Flying missiles, drones flying at low altitude, drones, especially long-range cruise missiles, whether over the sea or over the land, in order to increase the penetration of the aircraft, will try to depress the flight altitude, the so-called “sweep Sea ”or“ rub the tree a little ”flight. The research on the probability of water hammer or the probability of touchdown is one of the important topics in the above aircraft design. In this paper, we derive a formula to calculate the probability of land-based missiles touching the ground and compare them with the formulas commonly used in the past.