DBPapers
DOI: 10.5593/SGEM2014/B23/S10.024

IMPROVEMENT OF THE DIGITAL TERRAIN MODEL OF THE CZECH REPUBLIC OF THE 4TH GENERATION FOR THE AERIAL PHOTOGRAPHS ORTHORECTIFICATION

Z. Svec, E. Matouskova, K. Pavelka
Wednesday 1 October 2014 by Libadmin2014

References: 14th International Multidisciplinary Scientific GeoConference SGEM 2014, www.sgem.org, SGEM2014 Conference Proceedings, ISBN 978-619-7105-12-4 / ISSN 1314-2704, June 19-25, 2014, Book 2, Vol. 3, 191-198 pp

ABSTRACT
Since 2009 airborne laser scanning of the entire area of the Czech Republic has been carried out. One of principal products gained from acquired data is the 4th Generation Digital Terrain Model of the Czech Republic (DMR 4G). It is primarily created for production of the Orthophoto of the Czech Republic. Prior to orthorectification of digital aerial photographs the replenishment of some technical objects which are not a part of terrain surface (bridges, dams, etc.) into the model is necessary. Adverse image deformation of their representation in the orthophoto can be minimized using those complementary data. For the ortogonalization purposes at the built-up areas with a large number of high objects the true ortophoto is commonly used. Unfortunatelly, the true ortophoto production is very expensive, because it requires large side and forward overlaps of the aerial photographs and preparation of the digital surface model instead of digital terrain model. As the above mentioned project is countrywide, due to the economical reasons it is impossible to realize a true ortophoto as its output. As an alternative, ortogonalization by hybrid digital elevation model improved by some elements from current available geographic databases can be used. The article deals with the possible technological variants and data sources for digital terrain model replenishment and assesses application of each approach in practise.

Keywords: airborne laser scanning, digital elevation model, orthorectification, surface modeling, true orthophoto