1bul 2004
LASER SCANNING FOR TERRESTRIAL PHOTOGRAMMETRY, ALTERNATIVE
SYSTEM OR COMBINED WITH TRADITIONAL SYSTEM?
N. Demir', * , B. Bayram’, Z. Alkis’, C.Helvaci*, I. Cetin* T. Vógtle ^, K. Ringle , E. Steinle ^
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| * YTU, Civil Engineering Faculty, 34349 Besiktas Istanbul, Turkey - (demir, bayram, zubeyde, chelvaci,
| icetin)@yildiz.edu.tr
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° Institut für Photogrammetrie und Fernerkundung, Universitat Karlsruhe, Englerstr. 7, 76128 Karlsruhe , Germany -
(voegtle, ringle, steinle)@ipf.uni-karlsruhe.de
Commission V, WG V/2
KEY WORDS: Laser Scanning, Terrestrial, TLS, Terrestrial Photogrammetry, Modelling, Visualisation
ABSTRACT:
Traditional photogrammetric method has been a system for documentation, 3D modelling for long years. After the development of
digital photogrammetrical systems, map products can be monitored in CAD platforms. Placing models in CAD had verified
flexibility for getting information from model and easy editing for modelling. Terrestrial Laser Scanning Systems provide modelling of
objects without scale and complexness. Likewise the combination of laser scanning method and photogrammetric method or taking
in the consideration of the laser scanning method as an alternative method has been become a discussing topic. In this study, the study
area has modelled with both systems and after completed the comparison and combination of the both systems. 3D Model of the
building of University of Karlsruhe, Institute of Photogrammetry and Remote Sensing in Germany had been evaluated by
photogrammetric method. The 3D model of same scenery had been created by terrestrial laser scanning method. Then the
comparison of results from both systems had been done. To fusion the elevation data had been taken from laser scanning and the
spatial data from photogrammetric evaluation. The process steps had been explained and the results given.
1. INTRODUCTION * The way of scanning (360° scans, scanning specific
sections because of limited fields of view ,scanning of
profiles)
+ The deflection system(sweeping or rotation mirrors)
* The combination with other devices, mounted on the
laser scanner.
* etc. (Schulz, 2004)
Architectural photogrammetry has a big role for correct, scaled
documentation of buildings. By development of
photogrammetric and laser scanning systems, creating of
orthophoto, digital terrain models and monitoring has been
become rapid, correct and economical.
In last years terrestrial laser scanning systems have been got
usefulness for modelling processes. Processes may be done
without scale and complexness factor in laser scanning
Systems. Modelling of complex shaped objects is created by
point clouds in this system. All points of cloud have 3d
coordinates. Another superiority of lascr scanning system is
having tolls of data export at a file format. (Barber,2001)
When the laser scanner operates, all points are referenced to
internal coordinate system. If the object that has been modelled is
complex shaped, a series of scans will be necessary. The
multiplying scan series is be done by target points. 3d model is
produced by laser software and the data may be exported in
data export formats.(Bornaz, 2002)
Compared to the photogrammetric approaches the use of the
laser scanners has some advantages:
+ Direct acquisition of 3D points
The ability of ground based laser scanners to generate
thousands of 3D points over surface of interest in just a few
1 ^c 16 ali ~ Y Tor " ;
TRS IS a a ppealiug concept (Gordon, 2001) + This systems deliver an enormous amount of 3D
points on surfaces
Stereo Close Range photogrammetry has been the main tool in ; : a =
+ .— Excellent technique for the description of irregular
the field of 3D modelling for many decades. Hence it is well x ;
established technique , whereas laser scanning is a rather new surfaces relieves, sculptures, pillar capitals)
method for three dimensional object modelling. Since both * Results are avaible in a very short term
methods have their advantages and disadvantages, the goal is to
extract the positive aspects of each, in order to decade which is
suitable for certain application.(Vozikis, 2004)
Differentiations of laser scanners in a technical way concern
* Corresponding author.