In this article, we will learn about different characteristics of aerial photography. Aerial photographs differ from pictures captured using a ground based camera in several aspects. This is due to the difference in geometry of photography followed in airborne photographs.
Aerial Photography is the art and science of capturing photographs using a camera mounted on air borne platforms such as air planes, helicopters, drones etc. In some cases aerial photography is also performed using a camera placed on the elevated platforms such as towers, cranes etc.
In olden days people have used hot air balloons, pigeons and kites for acquiring aerial photographs. (Read: history and evolution of aerial photography )
What are Characteristics of Aerial Photographs:
Following are the characteristics of aerial photographs.
1. Synoptic Viewpoint:
Aerial photographs give the birds eye view of the terrain. They enable to observe the objects in their spatial context. Spatial relationship present among the features( terrain objects) which is not commonly seen between the objects can be seen in the photographs.
2. Time Freezing Ability:
Photographs are the records of spatial features, their physical and geometrical conditions at the instance of photography. Photographic records can be analyzed in the field or in the laboratory under controlled conditions with help of equipment for retrieving useful information. They serve as historic evidence and help in understanding the objects conditions in past at any time.
3. Capability to Stop Action:
Dynamic events such as floods, forest fires, oil spills etc., can be recorded using photographs. Using this characteristic it is possible to investigate how a phenomena or event is behaving w.r.t time (by capturing photographs in different point of times).
4. Stereoscopic Coverage:
It is possible to acquire the data stereoscopically using aerial photography. To get stereoscopic coverage, the study area is captured from minimum of 2 different locations consecutively in flight path while acquiring the aerial photos. The common area between the consecutive photographs is developed as a stereoscopic model. This helps in making measurements in a 3 dimensional fashion i.e., both vertically and horizontally.
5. Large Spectral Range:
Humans can see objects reflecting energy between 0.4 to 0.7 micrometers only. Photographs can be acquired beyond the human visible range of spectrum (0.4 to 0.7 micrometers). It is possible to capture photographs in regions such as infrared, microwave portions also. This opens for a huge set of things to explore and understand.
Aerial photographs are prepared by different agencies (both private and government) and are readily available most of the times. However, it is also easy to perform photography and acquire data in case if data is not available for any region.
Aerial photography is cheaper than ground based surveying when data is required over a large area. However, for smaller areas aerial photography becomes costly.
The above are some of the important characteristics of aerial photographs and aerial photography. These characteristics make aerial photography very useful and important in the field of geographical science and surveying.
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