S.Kadnichanskiy Digital oblique images and their application. The possibility of aerial survey system A3 in taking oblique aerial photography

Recently, in connection with the rapid development of information technology, geographic information systems, digital aerial photography and digital methods of processing of aerial photos oblique aerial photography and the use of oblique pictures acquire a new meaning and of great importance in solving very different tasks, though it is still not universally appreciated

Oblique aerial survey - aerial photography, the projected and the actual angle of deviation from the vertical optical axis of the camera for which are significantly different from zero values, for example, about 40 degrees

Geo-referenced digital oblique aerial photos is a fundamentally new type of product, which is a set of digital oblique pictures with parameters of external orientation, allowing to observe objects of locality with four or more different angles of view. Compared to the usual vertical pictures they provide even inexperienced users to easily interpret the image and giving fine bump of locality

When you use oblique aerial photos in a special software environments you can carry out the necessary spatial measurements

What is the oblique aerial photographs can be interesting and useful for comparison with the usual vertical aerial photos?

We don't just learn much more about the object on the image of him on the oblique aerial photo, but also understand the spatial character of the object and its parts, their three- dimensional spatial relations

We don't just learn much more about the object on the image of him on the oblique aerial photo, but also understand the spatial character of the object and its parts, their three- dimensional spatial relations

The advantages of oblique pictures: * Represented objects is significantly easier to be recognized, * Image contain much more information about the depicted objects, * Easy to determine the nature of the spatial (in three-dimensional space) extent and forms of objects, * Easily to define spatial (in three-dimensional space) arrangement of objects and their parts

As a result: compared usual vertical photos oblique picture provides even inexperienced users to easily interpret the image and navigate on it on the area becomes easier and quicker decision making in the analysis of visual spatial data

Oblique aerial survey is especially effective, if the subject is photographed from different angles, as a minimum, with four, which allows to observe it from different sides

Oblique aerial survey is especially effective, if the subject is photographed from different angles, as a minimum, with four, which allows to observe it from different sides

Oblique aerial survey is especially effective, if the subject is photographed from different angles, as a minimum, with four, which allows to observe it from different sides

Oblique aerial survey is especially effective, if the subject is photographed from different angles, as a minimum, with four, which allows to observe it from different sides

What's the purpose and applications oblique aerial photos are used in? The rapid response services - emergency medical assistance, security and rescue, fire-fighting. This is explained by the fact, that it is in these applications it is very important to quickly navigate, to determine the position of the object on the visual spatial data, assess the necessity of the situation around the object and the specific properties of the area and the object. For the decision making of various levels of local authorities and large enterprises, located on the large territories; information systems, operating perspective images, are very convenient continuation of (development) of the GIS. Realtor activity

Up-to-date oblique aerial survey - it's aerial photography of the territory provided a solid cover by oblique photos with some of the lend l and side overlaps. Moreover, these projected overlap s depending on the orientation of direction of photographing can be constant or variable in the field of the image

How and with what technical means are oblique aerial photos taken?

How and with what technical means are oblique aerial photos taken? Oblique aerial photography, as a rule, is performed simultaneously with the vertical aerial survey and may be accompanied by a lidar survey

Variants of technical solutions Complex of two oblique medium format cameras and a full-frame digital camera

Variants of technical solutions Specialized systems, including 5 medium format cameras on a single platform

Variants of technical solutions Use of aerial survey system, that allows to perform the vertical and oblique aerial survey by the same camera

Variants of technical solutions Such a system is a system A3, which company Meridian+ has and use

Features and advantages of the Vision system Map A3 for taking of oblique aerial photos Oblique pictures are obtained as a peripheral part of the large quasi panoramic pictures, covering strip degrees÷ degrees from the direction of the nadir Olique Images

Features and advantages of the Vision system Map A3 for taking of oblique aerial photos Large size of the oblique images, like for large format aerial cameras 7812 x pixels And as a result of this high productivity of oblique aerial survey Olique Images

Features and advantages of the Vision system Map A3 for taking of oblique aerial photos High spatial resolution (small GSD) for big heights of flight H=2300 m GSD=8 cm (β min) GSD=12 cm (β max)

Features and advantages of the Vision system Map A3 for taking of oblique aerial photos Aerial triangulation is performed with the use of all parts of the quasi panoramic image; as a result, the accuracy of the geo-referencing of oblique images comparable and is determined by the accuracy of aerial triangulation (comparable with the GSD)

Features and advantages of the Vision system Map A3 for taking of oblique aerial photos Example of the set of parameters of oblique aerial survey Height of Flight230 m GSD min 8 cm GSD max12 cm β min 25.5° β max 54.5° β aver 40° Image Size 7812 x Coverage Across Flight 1500 m

Example of A3 oblique aerial photo H=3000 m

Example of A3 oblique aerial photo H=5000m

Example of A3 oblique aerial photo H=5000 m

Conclusions Digital oblique aerial photographs can be successfully applied in all areas of application where you want the visual analysis and measuring the processing of spatial information - map, plan, orthophoto, but much more effective in comparison with the listed kinds of spatial data.

Conclusions Possessing many of the benefits for visual analysis, specific to the 3D models of the built-up areas, oblique aerial photos present a much more simple in the manufacture of a product that contains no derivative of the information about the object, but directly collected information.

Conclusions The advantages of using the system A3 for oblique survey can count on the high effectiveness of its use for these purpose

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