Kölbl, Otto 
  
The descriptive information had been linked primarily with the local presentations; nevertheless, reference had been 
established with respect to the overview presentations in order to allow the elaboration of synoptic presentation of all 
ksour (cf. fig. 3). This presentation concerned the whole Valley of the Dräa and allowed also the presentation of other 
architectural elements. 
  
  
enhaddou 
  
  
  
  
Figure 3 
In particular, we can subdivide the descriptive information in the following elements : 
1. Line and area symbols for geometric presentations 
2. Point symbols which can be summarised in libraries (cell library), cf. fig. 4 
Attributive information integrated in relational databases; this concerns mainly keywords allowing queries 
for the establishment of thematic maps 
Descriptions, images and sketches in text format which can be monitored over special links whenever needed 
Orthophoto as geometrically referenced raster images 
Images of facades with geometric references 
Geometric referenced video sequences 
> 
S 9 PR 
4.2 Selection of the information system and technique of data capture 
The preceding considerations made it evident that the CAD system MicroStation in connection with the information 
system MGE and facilities for the treatment of raster data will meet to a great extent the defined requirements. Accord- 
ing to the various evaluations, it seems that Arc View in connection with ArcInfo is - at least for the moment — not able 
to meet all the requirements, especially as for the 3D referencing. Without any doubt it would also be indicated to 
evaluate AutoCad. However, up to now it appeared that the possibilities for the connection with a database and the 
possibilities for the treatment of raster data are not quite satisfying. As far as known, this problem seems to be solved 
meanwhile. For a good part the choice was also influenced by the means available at the Institute of photogrammetry 
and the relevant experiences. The CAD system MicroStation allows the use of special elements, however it showed 
very soon that it was important to allow the indexation of individual façades. For this reason, it appeared necessary to 
construct the buildings by surface elements. In order to make the 3D-modelling as efficient as possible, the stereoplot- 
ting was limited to the capturing of the surrounding of the roofs. Subsequently, a script file is produced with the help of 
a Pascal program which represents the individual facades of the houses and their roofs in the command language of 
MicroStation. The script file can then be read immediately by MicroStation and produces the 3D object. A manual 
editing is not necessary. In parallel, it was of course necessary to measure additionally the terrain model. This terrain 
model is however in any case necessary for the elaboration of orthophotos. 
MicroStation can be connected with MGE (Intergraph) or with Geographics (Bentley). Tests with Geographics had 
been of quite some interest, showed however that system which is still in development has a great potential but at least 
  
450 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B5. Amsterdam 2000.