The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B4. Beijing 2008
450
As it is mentioned, this system is developed for acquisition and
maintenance of reliable 3D geo-information. This system uses
Oracle as its spatial database system and its constraint database
which is an object relational DBMS and it has high
interoperability, security and powerful functions. On the other
hand, this integrated system applies Photomod photogrammetric
system because of its popularity and accuracy and also its 3D
stereo environment. In this developed system, algorithms are
applied for the process of data structuring and correcting. All
parts of the presented system were built using Visual Basic 6.0.
This system uses Oracle as both its spatial database and
constraint database. For sending, retrieving and updating data in
the Oracle database, SQL commands were used in VB6, too.
The visualization part of this system that visualized the stored
3D geoinformation in the spatial database was also built using
Visual Basic 6.0 based on MapObjects(ESRI). It should be
considered that the stored spatial data in the database can be
visualized in other ways such as using ArcSDE(ESRI),
Microstation(Bently) and VRML, too.
3,1 Evaluation of the Developed System
For testing this system, aerial images of Shiraz (scale: 1:5000 ,
2004) were used. The photogrammetric model of this area was
produced in Photomod photogrammeric system. Then test
objects from different classes were extracted and saved in the
database by using OISDBPS system. Saved objects in the
database of the system have been assessed by three methods,
that are: a) evaluation of data accuracy in the digitizing
environment, b) displaying data of spatial database in the
visualization part of OISDBPS system, c) using Radius Check
software for labeling existing spatial errors in the database of
system.
The results of these tests have shown that the produced and
stored geoinformation by OISDBPS system is fully structured
and consistent (figure 4,5). Also time of data production is
saved considerably by using this system.
Area water feature
^ Mi Oli
and node
the permitte
Ibeparation
'insertion in
Kosertions
...
oiyqons
rea water feature
Closed Polygons
of Urban blocks
■msm
eparation and nod
insertion in the
ermitted insertion
Fixed elev of
Constructions
Closed Polygons
of Constructions
Fixed e ev of
Figure 4. Checking the produced data by OISDBPS system in the digitizing environment
Figure 5. Checking data in the visualization part of OISDBPS system