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:: USAGE OF AERIAL PHOTOGRAPHS. Ivan Landek, Stanislav Franges

Document type:: Monograph

Structure type:: Chapter

101 USAGE OF AERIAL PHOTOGRAPHS Ivan Landek 1 , Stanislav Franges 2 1 State Geodetic Administration Gruska 20, 10000 Zagreb, Croatia ivan.landek@dgu.tel.hr 2 University of Zagreb, Faculty of Geodesy Kaciceva 26, 10000 Zagreb, Croatia sfranges@public.srce.hr KEYWORDS: aerial photography, cyclical survey, usage of aerial photographs ABSTRACT: Aerial photographs in digital form are applied except for geodetic purposes in some other branches of activity being the users of spatial data. Cyclical aerial photogrammetric survey of the Republic of Croatia is an extraordinary important project for space management. The paper emphasises the importance of digital aerial photographs for the purpose of local administration and self-government, especially for land register, spatial planning, demining and for other purposes where the visualisation of spatial databases is needed, e.g. in the work of economic, utility, tourist and other institutions. 1. INTRODUCTION Photogrammetric survey is a surveying method using principally the photographs taken from the air. The results of photogrammetric survey can be the co-ordinates of single points, plans or some other graphic presentations and rectified photographs and the photomaps derived from them, photomosaics and panoramic photographs. According to the American society for Photogrammetry and Remote Sensing, photogrammetry is the art, science and technology of obtaining reliable information about the physical objects and environment by means of recording, measuring and interpreting the photographic images and electromagnetic radiation scenes obtained through sensor sistems. In the last twenty years, photogrammetry has been developing from analogous, through analytical to digital. During its historical development, photogrammetry has advanced into the sophisticated technology of surveying classical analogous photographs, and recently also into the survey of digital photographs. Exactly the survey of digital photographs and the possibilities of automated data gathering process makes digital photography be the optimal source of data for geoinformation systems. The present situation in photogrammetry and remote sensing denotes rapid development of: digital sensor techniques for obtaining the data; automation in data processing and photograph analysis; data management and analysis by applying CAD technology and geoinformation systems; data presentation with an emphasis on computer graphics, visualisation and animation. 2. AERIAL PHOTOGRAPHS Aerial photography is a picture of a certain area. This pictures shows the entire contents in its shape and dimensions by means of tone differences, and by means of colour tones on colour photographs). Thus, the photographs contain a lot of information, and from the cartographic point of view, there is too many information to be presented on a map. On the other hand, the photograph does not have some important information being present on a map. These are titles, co-ordinate system and unique scale. Further, the photographs are made in central projection, and maps are made in various other projections. On single photographs, height image is rather weak and can be obtained indirectly (using shades, communication forms, form of parcels and the direction of their spreading, supporting walls, vegetation etc.), and the stereoscopic observation of photograph pairs give more reliable and clearer relief image. Hence, maps and photographs do not exclude each other in offering information, but they supplement each other which has led to the production of photomap (Lapaine and Francula, 1998). Apart from analytical systems used now in photogrammetry, and photograph digitising with special scanners, digital systems will very soon be used in a much broader sense. The development of high-resolution sensors has helped digital systems to reach analytical system completely, referring to accuracy, and in some areas, they are already preferred, e.g. in digital relief models. Apart from that, their usage will enable the introduction of new technologies and the production of new products (Fiedler, 1998). Photogrammetric survey of classical analogous photographs in analytical form yields data in vector form. It has all the advantages and disadvantages of such an imagery. Vector form of data is convenient for vector oriented GIS. GISs are mostly developed with an aim to present and analyse the data as well as possible from the existing topographic maps. Vector model of points, lines and traverses in uninterrupted co-ordinate space allows the closest approximation of existing maps. But the structure of data is more complex than the raster structure and certain operations with vector data are more complex. Because of a large quantity of attributes per data unit, they make the vector model much more expensive. Unlike the vector oriented GIS, a large number of users are more familiar with the raster oriented GIS. The data for such systems are obtained mostly with sensors placed on satellites or aircraft. Raster data divide the surface into identically shaped unit image elements - pixels, saved as two-dimensional quantities in a computer, and each

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