论文部分内容阅读
垂直航空摄影像片上存在的投影差,使得坡向向像主点的坡长影像相对延长,逆像主点的坡长影像相对缩短,这在高差大、坡向变化频繁的山区更为显著。当坡长影像长度小子于其理论影像长度的2/3时,坡面上的各地类界线难以判清;小于1/2时,则坡面上的许多地类都难以判出。因此,以像主点为中心的航片最适有效作业半径r_1≤- H_A/2h D_1=f/3tgα,极限有效作业半径rm=- H_A/h D_1=f/2tgα,即最适和极限有效作业半径决定于逆向坡高差h的负值和坡长影像长度D_1或地面倾角α。
The difference of projection on the vertical aerial photography image makes the slope length image of the main point of the slope to be relatively extended, and the slope length image of the main point of the reverse image relatively shortens, which is more significant in the mountainous area where the elevation difference is big and the slope change is frequent . When the length of the image is less than 2/3 of the length of the theoretical image, the boundary of each class on the slope is difficult to distinguish. When it is less than 1/2, many types of land on the slope are difficult to judge. Therefore, the radius of the effective working radius r_1 ≤-H_A / 2h D_1 = f / 3tgα and the effective working radius rm = -H_A / h D_1 = f / 2tgα, that is, the most suitable and effective limit The working radius is determined by the negative value of the reverse slope height difference h and the image length D_1 of the slope length or the inclination α of the ground.