A
Areas where high-rise buildings (10 stories or more) are concentrated in the center of a large city
B
Areas where buildings such as houses with trees and a height of about 3.5 m are dense / Areas where middle-rise buildings (4 to 9 floors) are scattered
C
Areas in which obstacles with a height of 1.5 to 10 m are scattered / Areas in which trees and low-rise buildings are scattered
D
Areas where there are few obstacles and the average height of the surrounding obstacles is 1.5 m or less (coast, grassland, airfield)