You are using an outdated browser that does not fully support the intranda viewer.
As a result, some pages may not be displayed correctly.

We recommend you use one of the following browsers:

Full text

International cooperation and technology transfer
Fras, Mojca Kosmatin

Ivan Landek 1 , Stanislav Franges 2
1 State Geodetic Administration
Gruska 20, 10000 Zagreb, Croatia
2 University of Zagreb, Faculty of Geodesy
Kaciceva 26, 10000 Zagreb, Croatia
KEYWORDS: aerial photography, cyclical survey, usage of aerial photographs
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.
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
data management and analysis by applying CAD
technology and geoinformation systems;
data presentation with an emphasis on computer
graphics, visualisation and animation.
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,
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