低空或掠地飞行是现代军用飞机的典型飞行高度。然而,在60米高度以下,由于电力线、铁塔、电线杆和拉线等地面障碍物极多,再加上人为的对抗措施(如防空袭用的阻塞气球缆索等),都对高速喷气机和直升机构成了严重威胁。然而,人眼和当前装备的机载传感器均难以发现上述障碍物,特别在夜间或恶劣气象条件下,因而飞机的飞行高度受到了限制。 Low-altitude or grazing flight is the typical height of modern military aircraft flying. However, at a height of up to 60 meters, ground obstacles such as power lines, towers, telephone poles and cables, coupled with man-made countermeasures such as blocking balloon cables used in air defense, have been widely used in high-speed jets and helicopters Pose a serious threat. However, the above-mentioned obstacles are hard to find in both the human eye and currently equipped on-board sensors, especially at night or in bad weather conditions, and hence the flight altitude of the aircraft is limited.