Topographic surveying: aerial photography using aircraft
The Foundation of any topographic products (map or plan) is a topographical survey of the area. The main method of capturing large areas is aerial photography. The commander and Navigator of the aircraft is responsible for flight, the operator for the most valuable cargo of the aircraft of the photographic camera. Using the autopilot leveled aircraft flight. Aerial photography can be performed only in cloudless weather, because the presence of clouds in the sky will prevent the obtaining of clear photographs of the area.
At a height of several hundred meters after the entrance into the working area starts photographing. The plane flies around the place shooting a kind of zigzag. Each subsequent pass overlaps the previous by 60%. This ensures getting the frame all that is on the ground. Guided photographic equipment an operator located in the cabin of the aircraft via a laptop. The main advantage of modern photographic equipment is a platform that moves. The camera moves perpendicular to the motion of the aircraft. Due to this, it is not the only planned shots, but promising. Moving the camera makes for 7 high-quality images per second. A special computer program, which will be processed photos, eliminates all the shortcomings that arise while shooting.
Hard disk the images transferred to the office. Pictures can be created in vagrant a few thousand. Then they will handle the engineering photogrammetrist. First and foremost all images taken during the flight, you need to match each other - this process is called the cap Assembly. Now a swivel mounting for a few minutes, the computer carries out. Images are oriented to bind to the surface of the earth. In the processing points on the frame are assigned spatial coordinates, and step by step images are stitched together into a single map. When the card is manufactured, each point here corresponds to a particular location. Modern aerial photography allows you to create not only conventional map and three-dimensional. For trimms model to measure vostu house, tree or other object and set their planned position.
Topographic surveying: aerial photography using lethal devices
The current process of aerial photographing of the territory from the height of hundreds of metres to tens of kilometres is significantly simplified, compared with 1925, the year of the emergence of aerial photography. Where the implementation of aerial photography needed dozens of experts and a large aircraft. There are now unmanned model airplanes by installing on-Board camera used for aerial photography.
A model of a drone in the collapsed state is delivered to the place of aerial photography at conventional car. After bringing the aircraft into position and check it is launched. UAV design makes it very stable in the air, it can work at low altitude. The plane is controlled from the ground using radio transmission pristy. The plane is oriented in space, guided by a GPS sensor. On the ground the engineer controls the aircraft through the station that sets drones on the fly. Information on aerial photography gets on the stick and then transmitted to the office, where will be compiled the map.
Topographic surveying: land surveying tacheometric
Small sections off ground methods. A very common method is tacheometry survey using total station.