International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV. Part B2. Istanbul 2004
applied effectively. It means that such fragments must
be smooth enough and be free from vegetation,
buildings, etc.
- The aim of the next operation is the transfer of the
selected "favourable" fragments (their mathematical
representation) to the coordinate system of each aerial
photo taking into account their visibility (these
fragments may be shielded by terrain features or on-
ground objects).
- Using only selected "favourable" fragments (more
accurate, their projections onto the photo plans) the
stereo model is produced, which now is free from
miscorrelation. Of course, such a model is not full,
because it is made up from fragments. But this is not
a problem with this real-time mapping approach,
because the created model has onlv auxiliary meaning
unlike the traditional stereotopography method.
- . After that the model produced during the previous
stages is finally orientated relatively laser-derived
DTM, that corresponds to its orientation in geodetic
space. Naturally, the orientation. of each frame is
carried out also.
GPS principal point coordinates for each photo strictly
determine the stereo pair position in space with only one
degree of freedom - angle of turning around survey basis
vector. So, the final true stereo model orientation in relation
to DTM may be done by minimising spatial misalignment
function for both laser-derived and photogrammetrical
terrain surfaces. This can be done using R.M.S. method, for
example.
The described method is just a technological basis for
Geokosmos’ activity in all parts of the world for
miscellaneous application. In addition to topography survey
and DTM making which are definitely the main lines of the
both companies’ activity, there are some other important
applications where this technology is successtully used.
These include:
- Power lines inspec
- GIS and land use s
- Forestry;
- . Coastal mapping and monitoring;
- Avalanche and flood prediction;
For more relevant information see the articles listed at the
end of this paper and also the Internet sites of both
companies.
tion;
ystems;
9. CONCLUSIONS
The technology of real-time mapping was originally
introduced by Geokosmos and successfully tested in
different aerial survey projects all over the world. This
technology is commercially available for customers, it is
based on Geokosmos proprietary software and hardware
products and is permanently updated to enhance its
effectiveness. The technology proved its applicability for
wide range of topography and non-topography applications
where it can be used instead of combining traditional
photogrammetrical and geodetic methods.
References from Journals:
Medvedev E., 2002. Simultaneous recording of LiDAR and
aerial imagery", GIM international, January, #1, Volume
16, p.12.
References from Other Literature:
Danilin L, E. Medvedev, T. Sweda, "Use of Airborne Laser
Terrain Mapping System for Forest Inventory in Siberia",
180
Proceedings of the Ist International precision forestry
cooperative symposium, Seattle, WA.,U.S.A., p.67.
Medvedev E. 2000. Digital automatic orthophoto
production with laser locator and aerial photography data",
ISPRS WG VI/3 andIV/3 Workshop, Ljubljana, Slovenia,
February.
Medvedev E., 2001. Automatic calibration. procedure for
laser scanning systems, In Proc. 5th International Airborne
Remote
Sensing Conference and Exhibition, San-Francisco, CA,
U.S.A.
Medvedev E., 2001. Combining laser scanner and digital
photography data for automation of orthophotomap
production, In. Proc., 5th International. Airborne. Remote
Sensing Conference and Exhibition, San-Francisco, CA,
U.S.A.
Medvedev E., Kapralova E., Danilin I., 2000. Laser locator
methods for forest structure analyses, In Proc. 3rd
International Conference on geospatial information in
agriculture and forestry, Denver, CO, U.S.A.
Medvedev E. Vagners D… 2004. Practical use of
Geokosmos real-time Cartography technologies based on
Optech's Airborne Laser Terrain Mapping System, In Proc.
of annual international conference Map-India, New-Delhi.
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