Aerial Photography and Its Origin

Aerial Photography


The term aerial photography refers to the process of taking photographs of the ground without the support of a ground-based structure from a position which is elevated/direct-down.

Platforms that are used for aerial photography usually include fixed-wing aircraft, helicopters, unmanned aerial vehicles (UAVs or "drones"), rockets, balloons, kites, parachutes, stand-alone telescopes and vehicle-mounted poles. Mounted cameras on drones may be triggered remotely or automatically.

Aerial photography and air-to-air photography are two different aerial method of photography. In air-to-air photography one or more aircraft are that "chase" and photograph other planes in flight which are known as chase planes

History of Aerial Photography


The first ever aerial photograph taken was an oblique aerial photo of a French village in the late 19th century.
Photographer Gaspar Felix Tournachon is the man who took it and thus patented the idea of using aerial photographs to compile maps.
It was to prove much more effective than the time-consuming ground surveys thus more commonly-used method of the national mapping organizations that developed throughout the 19th century (such as the UK's Ordnance Survey) was renounced eventually.


Following the 1906 San Francisco devastating earthquake, George R. Lawrence took its aerial photographs but the potentiality of military applications of aerial photographs were overlooked till World War I that a systematic process of capturing aerial photographs might change the overall development process.
Archaeologist OGS Crawford initiated taking aerial photography for this purpose, finally comprehending its huge potentiality. In order to keep up to date with the enemy developments and movements, both allies and the Germans started taking aerial photographs of each other’s resources and lines.
Experiencing huge success of this observation method of aerial photography, the British used aerial photography during World War II once again, availing archaeologist teams to elucidate masses and masses of photographs taken for aerial reconnaissance concerns. After the war seeing the huge potential, researchers began using aerial photography which welcomed the beginning of the modern way of landscape studies, natural processes, and archaeological features.

Although not entirely eliminated, aerial photography became less important with the arrival of satellite imagery developed by space agencies.
The Cold War and the introduction of color photography meant that military applications continued and it was during this time that wider environmental applications developed too. Aerial infra-red photography became important tracking and identifying diseased plants and trees and also to vegetation mapping.
Gaspar Felix Tournachon
George R. Lawrence
George R. Lawrence

Working Principle of Aerial Photography


Aerial photography just might sound simply as the process of taking photographs from the air, but it is more than just using a light UAV and flying up to take photographs. There are many factors to an aerial photography that must be considered to ensure that the photo is useful enough to extrapolate whatever is being captured.

It is often hard to interpret elements of the landscape on the ground, features can easily be missed, and what might seem like a trivial bump from ground level can become more remarkable in a wider view. Thus aerial photographs are vital to study and map the landscape types that are difficult to access by human.

Aerial photography have been used as a method to study landscape for over a long period of time, mostly in archaeology and researchers have learnt so much about the world around us; its applications have reached a broad spectrum and accompanied with the growing GIS (geographic information systems) technology, meaning that this method of observation will not cease to exist soon.

Aerial photographs are captured in two basic forms with both having different uses and applications: oblique and vertical.


Even today black and white images are preferred in an age of high quality digital imaging. This is because they are cheaper and also because the contrast of black, white and greys makes it easier to identify the features.

Vertical Oblique Photography

Oblique


Typically taken at 45 degrees but as they can be taken at any angle which gives the best view of the targeted region. These are often taken manually and majorly used in archaeology to take a wider context of a feature and the area around it.

Oblique aerial photographs are taken for a specific purpose and its application are quite limited. These are captured at a lower elevation than the vertical image and in few numbers. A problem in perspective inevitable as the farther away a feature is, the smaller it will look: nearer objects of comparable size look larger than those that are farther away. Thus it is advisable to use a frame of reference for better and accurate perspective. Small fixed-wing aircraft and helicopters are used to capture oblique aerial photographs and are best suited to monitor erosion of monuments and features over a certain period of time.

Vertical


The more familiar form of aerial photograph is taking a photograph straight down over a landscape. It is a plan view so there is no chance of distortion of the image. This also indicates that it is rather very difficult to elucidate the layout of the land like changes in height. This helps to provide a good impression of the various elevation of land. These are captured at regular heights for consistency so it is rather very easy to differentiate among landscapes taken on the same day, or many years apart.

Vertical aerial photography mostly concentrates on topography and are rarely used in archaeological applications. Some exceptions perhaps might be to find interesting earthworks and other sites that are conveniently overlooked on the ground.

Oblique Vertical

When Best To Take Aerial Photographs

Oblique Photographs


The time of year is vital when it comes to aerial photography and winter is supposedly the perfect season to take aerial photographs. There are many reasons for this, not because it is convenient to see features in fields that do not have crops and will not be ploughed for several more months to come. This is mainly because the surviving features beneath the surface will often show up darker for the shallower levels of soil.

Snowy and frosty conditions help to perfectly emphasize ridges and features and they can be photographed with a clarity that cannot be seen at any other time of the year. Much longer shadows are casted due to the low level at which the sun rises, making visibility of above ground features much easier to spot.
That's does not mean that warmer months and longer hours of light are not convenient to aerial photography. Late evening conditions help to cast longer shadows and between morning, afternoon and evening the differing lighting level can add depth to the images.

Vertical Photographs


By rule, vertical aerial photographs are easier to clarify than oblique photographs as these are taken in the standardized ways that is at a single non-arbitrary angle with set scales. Even with favorable conditions, vertical aerial photographs lack perspective and other effects of that an oblique image. At higher levels, small details may be missed out. Vertical photography is the best way to go if it’s only about an overview of a landscape. 

 

Applications of Aerial Photography

Drone aerial picture

In Archaeology

To locate archaeological lost monuments, generally invisible at ground level, under the soil, and that can only be seen under some specific conditions, aerial photography is the ideal choice.

Machupicchu archaelogical picture
In Climate Change

Climate change has a global impact that can be strongly felt at the present moment. We are able to survive in this ordeal just because the researchers were able to keep track of the river beds drying up, droughts getting longer, wetter seasons getting wetter, and drier seasons getting drier, so they were able to put forth the tactics to survive this ordeal.

All these have been possible due to the constant observation of the landscape images all over the world taken with the aid of aerial photography. Researchers are still trying to find the solutions by analyzing the images captured with the aid of aerial photography.

In Other Earth Sciences

The geologists’ interest in aerial photography is due to the natural changes that can be noticed in these images over a period of time.

Aerial photography does not help geologists directly. So it is rather not beneficial for them. But by observing the gradual changes in the environment, the geologists can predict the future ordeal that we might need to face.

arial picture