International cooperation and technology transfer

Fras, Mojca Kosmatin

Bibliographic data

Monograph

Persistent identifier:: 856490555

Author:: Fras, Mojca Kosmatin

Title:: International cooperation and technology transfer

Sub title:: Ljubljana, Slovenia, February 2 - 5, 2000 : proceedings of the workshop

Scope:: VI, 163 Seiten

Year of publication:: 2000

Place of publication:: London

Publisher of the original:: RICS Books

Identifier (digital):: 856490555

Illustration:: Illustrationen, Diagramme

Language:: English

Usage licence:: Attribution 4.0 International (CC BY 4.0)

Publisher of the digital copy:: Technische Informationsbibliothek Hannover

Place of publication of the digital copy:: Hannover

Year of publication of the original:: 2016

Document type:: Monograph

Collection:: Earth sciences

Chapter

Title:: DIGITAL AUTOMATIC ORTHOPHOTO PRODUCTION WITH LASER LOCATOR AND AERIAL PHOTOGRAPHY DATA. Evgueny Medvedev

Document type:: Monograph

Structure type:: Chapter

119 DIGITAL AUTOMATIC ORTHOPHOTO PRODUCTION WITH LASER LOCATOR AND AERIAL PHOTOGRAPHY DATA Evgueny Medvedev Opten Limited, Moscow, Russian Federation Commission V, Working Group 4 KEY WORD: Laser scanning, digital aerial camera, orthophoto rectification, DTM, IMU ABSTRACT Application of traditional aerial survey technologies for topographic purposes has a number of principal problems. The most serious problem is definitely impossibility of automatic use of classical stereophotogrammetry methods in cases of complex terrain, urban areas, the areas with no visual texture and so on. It is well recognized by now that laser locator methods are very efficient for such kinds of work. The proposed approach is based on the following main principles: 1) Original 3D nature of laser locator data in combination with an absolute geodetic accuracy of 10-15 cm, unachievable to traditional methods of aerial topography survey, allows to suggest a number of effective algorithms of fully automatic recognition, delineation and positioning for the objects such as Digital Terrain Model (DTM), water surface contours, forest arrays, single trees, buildings. 2) Laser locator survey can be successfully combined with digital aerial photography during both on-board data acquisition and on-ground processing. Indeed, the application of Global positioning system (GPS) navigation complex + inertial measurement unit (IMU) on board required for correct laser locator data interpretation makes it possible to record 3D coordinates of principal points and angles of optical axis orientation for each frame, which in turn provides the 99999999999999 Presented approach ensures automatic topographical mapping in scale 1:2000 - 1:5000 with total productivity of 200-300 km per day. The special software for automatic mapping and some examples of realization are described. 1. CLASSIC STEREOTOPOGRAPHIC METHOD: ADVANTAGES AND PROBLEMS Despite the permanent development of digital photogrammetry methods the complete automation of relief part of map production and orthorectification of aerial photos can hardly be achieved within the classic approach. Leaving alone the outdated and extremely unproductive purely ground based methods of relief depiction, a currently dominating based on aerial survey data so called stereotopographic method of production and upgrading topographic maps and plans, is reviewed, that method allows both relief reproduction and orthorectification in cameral conditions. An attempt to automate the method faces the complications conditionally divided in two categories: 1) Disadvantages of method. This category is made up of a group of major photogrammetric problems, which being put together mostly limit the method application in topography in general. By recent times such were rather considered as natural limits of application but not problems. Reference to them as the problems is now due to recent alternative solutions appearance. Stereotopography method assumes the imperative on ground geodetic plan/elevation support of aerial survey results. Within such, a limited in volume geodetic survey of the area relief is performed, that is conditioned by high cost and low productivity of on-ground geodetic works. The results on this stage, being spatial coordinates of ground control points, are only used for photo triangulation extension, that results in supporting geodetic net spreading on all aerial photos of a project thus providing each with 5-6 secondary control points. This in turn allows absolute spatial orientation of photos, and their mutual orientation in stereopairs, upon which one may immediately begin retrieval of relief in absolute coordinates and orthorectification. Such is, in brief, a content of the classic stereotopography method that is obviously well known to everyone aware of photogrammetry in general. The major conclusion that can be done of the above brief description is - so produced relief model is only with small degree (particularly in a volume of on-ground geodetic support) provided with independent control measurements. The rest of necessary information appears within the stereotopography method itself, and therefore by definition contains no mechanism of correctness and accuracy control. The above described technique may be, indeed, divided into four general processes:

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