CA, 9-11 Nov. 1999 
is possible to extract height 
ment which could be used to 
Mabases with quantitative 3D 
iutomation may be necessary for 
oof ridges acting as guidelines 
| of the roof structure. 
D CONCLUSIONS 
se of relatively low resolution 
| of roof detail from buildings, 
ng. A 2D spatial database of 
ised to locate the roof extents. 
to test the LIDAR data, an 
nple roofed buildings, and a 
1ildings and more complex roof 
f LIDAR elevation, aspect and 
e made to extract the main roof 
gest that it is possible to extract 
ta, especially for large buildings 
he aspect parameter performed 
majority of ridges from the 
dges using aspect, just over half 
natches. In the residential areas, 
complex roof structures made it 
ata to produce meaningful roof 
imilar or lower resolutions will 
problems experienced in this 
lanimetric accuracy levels of the 
> to the extraction of accurately 
detail. The problems with the 
ven though the buildings used in 
relatively simplistic structures. 
level of roof detail extracted in 
pplications such as visualisation 
A semi-automated approach to 
eed to be employed for these 
lges can be used as a guide for 
tent and nature of the ridges. To 
etail that can be extracted from 
on, or rather the original point 
" should be made more dense. 
he cost of the data and make it 
r scanner users. LIDAR data 
nproved further, as well as the 
n LIDAR data and any assisting 
data set used in this paper. Until 
Tr scanner instruments becomes 
st of the technology decreases, 
r scanner data can be used to 
| buildings. 
  
International Archives of Photogrammetry and Remote Sensing, Vol. 32, Part 3W14, La Jolla, CA, 9-11 Nov. 1999 
ACKNOWLEDGEMENTS 
We would like to thank Dave Holland, Sallie Payne and all at 
the Ordnance Survey for help and advice. The Ordnance 
Survey of Britain kindly provided the Land-Line data set. 
Thanks to the Environment Agency for the supply of the 
LIDAR data. Research and computing facilities were made 
available by the School of Geography, University of 
Nottingham. 
REFERENCES 
Axelsson, P., 1999. Processing of laser scanner data - 
algorithms and applications. ISPRS Journal of Photogrammetry 
and Remote Sensing, 54 (2), pp.138-147. 
Braun, C., Kolbe, T.H., Lang, F., Schickler, W., Steinhage, V., 
Cremers, A.B., Forstner, W. and Pliimer L., 1995. Models for 
photogrammetric building reconstruction. Computer & 
Graphics, 19 (1), pp.109-118. 
Frère, D., Hendrickx, J., Vandekerckhove, J., Moons, T., Van 
Gool, L., 1997. On the reconstruction of urban house roofs 
from aerial images. In Automatic extraction of man-made 
objects from aerial and space images II. (eds) Griien, A. 
Baltisavias, E. and Henricsson, O., Birkhauser, Berlin, pp.87- 
95. 
Grüen, A. and Dan, H., 1997. TOBAGO: A topology builder 
for automated building model generation. In Automatic 
extraction of man-made objects from aerial and space images 
II. (eds) Grüen, A., Baltisavias, E. and Henricsson, O., 
Birkhauser, Berlin, pp.149-160. 
Haala, N. and Brenner, C., 1999. Extraction of buildings and 
trees in urban environments. ISPRS Journal of 
Photogrammetry and Remote Sensing, 54 (2), pp.130-137. 
Hug, C., 1997. Extracting artificial surface objects from 
airborne laser scanner data. In Automatic extraction of man- 
made objects from aerial and space images II. (eds) Grüen, A., 
Baltasavias, E. and Henricsson, O., Birkhauser, Berlin, pp.203- 
213. 
Huising, E.J. and Gomes Pereira, L.M., 1998. Errors and 
accuracy estimates of laser data acquired by various laser 
scanning systems for topographic applications. ISPRS Journal 
of Photogrammetry and Remote Sensing, 53 (5), pp.245-261. 
Lang, F. and Fórstner, W., 1996. 3D-city modelling with a 
digital one-eye stereo system. International Archives of 
Photogrammetry and Remote Sensing, Band 31, B4, pp.261- 
266. 
Lohr, U., 1998. Laser scanning and DEM generation. In GIS 
techniques and their applications. (eds) Brebbia, C.A. and 
Pascolo, P., Computational Mechanics Publications, 
Southampton, pp.243-249. 
Jaafar, J. and Priestnall, G., 1998. Automated DEM/DSM 
accuracy estimates towards land change detection. In GIS 
techniques and their applications. (eds) Brebbia, C.A. and 
Pascolo, P., Computational Mechanics Publications, 
Southampton, pp.73-82. 
Jaafar, J., Priestnall, G., and Mather, P.M., 1999. Assessing the 
effects of grid resolution in laser scanning data sets towards the 
creation of DSMs, DEMs and 3D models. Presented at 21% 
Canadian Symposium on Remote Sensing, Ottawa, Ontario, 
Canada, 21-24 June 1999, pp.606-613. 
Maas, H.G. and Vosselman, G., 1999. Two algorithms for 
extracting building models from raw laser altimetry data. 
ISPRS Journal of Photogrammetry and Remote Sensing, 54 
(2), pp.153-163. 
Newton, G.D., 1996. Inclusion of height in digital database - 
Feasibility Study Version 1.0b, unpublished. 
Weidner, U., 1997, Digital Surface Models for Building 
Extraction. In Automatic extraction of man-made objects from 
aerial and space images II. (eds) Grüen, A., Baltisavias, E. and 
Henricsson, O., Birkhauser, Berlin, pp.193-202.