Abstract: A method for constructing air-observed terrain data by using a rotary wing structure includes setting flight information including a photographing starting location and a photographing ending location on the basis of a flight route and a photographing location of the rotary wing structure; transmitting, to the rotary wing structure, the flight information so as to store the flight information in a flight control unit; capturing a ground image by a photographing unit of the rotary wing structure and storing the ground image in a storage unit when the rotary wing structure arrives at the photographing location; ending photographing and returning to the ground when the rotary wing structure arrives at the photographing ending location while repeatedly capturing a ground image; and constructing, by a computer in the control center, terrain data by using ground images stored in the storage unit.

Abstract: The present invention relates to a bullet including an air-guiding recess, comprising: a head 20; and a tail 30 disposed behind the head 20, and including an odd number of air-guiding recesses 32 formed so as to be curved in the bottom and outer circumferential surfaces thereof. The air-guiding recess 32 is characterized by having a sloped bottom that increases in depth while progressing to the bottom surface of the tail 30. Accordingly, vortex is prevented from being generated at the rear side of the bullet, so as to significantly increase the effective range thereof and simultaneously improve accuracy when shooting same.

Abstract: The present invention relates to a bullet including an air-guiding recess, comprising: a head 20; and a tail 30 disposed behind the head 20, and including an odd number of air-guiding recesses 32 formed so as to be curved in the bottom and outer circumferential surfaces thereof. The air-guiding recess 32 is characterized by having a sloped bottom that increases in depth while progressing to the bottom surface of the tail 30. Accordingly, vortex is prevented from being generated at the rear side of the bullet, so as to significantly increase the effective range thereof and simultaneously improve accuracy when shooting same.