The Use of Unmanned Aerial Vehicle Surveys
Aerial survey is a method by which geomatics, as well as other imagery in general, are collected by the use of UAV’s, planes, balloons, helicopters, and other methods. Normally, the kind of data collected in the aerial survey includes aerial photography, remote sensing by the use of both invisible and visible spectrum’s that are electromagnetic such as ultraviolet, infra-red, and gamma, and data that is geophysical such as gravity and aero-magnetic types of surveys. Aerial surveys may also refer to maps or charts that are made through the analysis of a particular region from the air. Aerial surveys have some distinct factors that are different from the technology used in satellite imagery such as conditions related to the atmosphere, quality, and resolution. Presently, the term aero photogrammetry is used as a synonym for aerial surveys, which involves placing a camera in the air as part of photogrammetry. Photogrammetry method and technologies provide the aerial images measurements.
UAV’s, which means unmanned aerial vehicles, are typically known or referred to as drones as well as numerous other names such as a non-human piloted aircraft. They are referred as such because they can be remotely controlled by a pilot in another vehicle or on the ground or controlled autonomously by computers placed on board of the UAV. The autonomous aircraft’s are presently considered to be inappropriate for regulation because of their liability as well as legal issues. On the other hand, aircraft’s that are remotely piloted are considered at par and under relevant national aviation authority as well as a civil regulation under the ICAO.
UAV’s undergo a recovery method function and a typical launch of an external operator situated on the ground or in another vehicle or an automatic system. In times past, UAV’s were aircraft’s that were simply piloted remotely; however, autonomous control is being used in an increasing manner.
UAV’s have mostly found applications in special operations and the military, though there are numerous and increasing uses found in civil applications such as surveillance, fire fighting, policing, and security work that are non-military such as pipelines or power inspections. Unmanned aerial vehicles are normally preferred for dangerous, dull and dirty kinds of missions where it would be next to impossible to send in aircraft’s that are manned. UAV’s also now play a huge part in science as they are great for collecting data in dangerous areas.
Unmanned Aerial Surveys are also used for fishery surveys, hydrocarbon explorations, archaeology, mining, land surveys, geophysics, reconnaissance, monitoring insect and wildlife populations (also known as sampling or aerial census), mining, monitoring the ground cover as well as the vegetation, monitoring projects related to transport such as bridges, roadways and the interstate.
Basically, remote aerial surveys links advanced technologies in UAV’s, Unmanned Aerial Vehicles, together with advanced uses of pieces of equipment that are used in imaging for the purpose of achieving a wide variety of both aerial and mapping surveys that are of high quality. UAV’s are considered to be among the best in the provision of more specific and more up-to-date data.
Some common terms that are used in UAV aerial surveys include:
Air station or exposure station: this is the optical centre’s position of the camera during the exposure time.
Flying height: this is the exposure station’s altitude above the sea level, which is also known as a datum.
Altitude: this is the distance, vertically measured, between the earth surface and the aircraft.
Tilt: this is the angle in between the horizontal axis that is upright to the line of flight and the aerial camera.
Tip: this is the angle in between the line of flight and the aerial camera.
Principle point: this is the connection point of the photographic plane with the aerial camera’s optical axis.
Isocenter: this is the point on the aerial photograph where the photograph meets the bisector angle the tilt.
Nadir point: this is the point on the aerial photograph, also referred to as nadir image, where a dropped plumb line from the nodal point that is at the front penetrates the photograph.
Scale: this is the ratio of the camera’s objective focal length and the exposure station’s distance from the ground.
Some of the main benefits of using UAV’s aerial survey include:
Improved data collection efficiency and accuracy.
An enhanced productivity in the work flow.
Efficiently and safely produce turn keys that are cost-effective on demand.
Countries: United Kingdom