ther
sub
pli-
zed
iple
the
ntal
Ake
Pb hic
phic
aps
ital
5 of
and
l as
use
ion
ata
rid
| in
lata
the
Ihe
- input data,
- processing techniques for integration of
several data types into GIS,
- hybrid GIS database,
- processing and enhancement techniques
for building new GIS levels as well as
output data,
output data as results of application
questions.
These subsystems contain many other second order
subsystems which are connected sometimes or not. A
much more detailed separation of the subsystems will
not be described now, but figure 6 illustrates how the
system architecture can be seen in principle.
It is shown how the different input data on the left
hand side will be processed, with geometrical or
radiometrical techniques e.g., before the data are inte-
grated in several GIS levels. On the right hand side
composing and enhancement methods are figured
out, for creating new derived GIS levels and also for
the data output as results of user requirements. The
output data itself are not separated in conventional
and digital results or other more detailed possibilities,
these details are included in the shown resulting
groups.
digital or
input data hybrid GIS conventional
output
non graphic interactive : large scaled
data input object-. signature-, [ "| maps
thematic databases
1
geodetic input and topographic
survey adjustmen vector database [ | maps
Cartographic A
generalization
digitized or
scanned map
ransform.
data conv.,
hybrid edit.
continuous raster
(with color index)
small scaled
topographic
maps
of vectordata
output \
3 transfor—
photogramm.
measurement
grid data (DEM e.g.)
mation A
image maps
4
scanned
aerial
hotographs
airborn
scanner data
pre-
processing
dig. image
grayvalue raster data
(single images.
hill shading e.g.)
derived raster data
geometrical
image proc.
radiometrical
image enhan
cr
thematic
maps
informations.
processin (mosaic, classification,
elc.)
i | statistics
y
6
digital 3
satellite cartographic
images generalized
database
hybrid comp.
and generalizing
hybrid editing
statistical input and
non graphic actualizin
data
hybrid compared data
8
2,3,5...8
Fig.6: Hybrid GIS system architecture
In this GIS architecture the hybrid database itself
includes 8 subsystem levels, where the non graphic
database is not more detailed (just level 1). The graphic
database is separated twice: original data (level 2...5)
and derived data (level 6...8), both containing of
vector-, raster- and grid data levels. Most of the ori-
ginal data belong to the topographic database and most
of the derived data build the application database.
These both main subsystems of a GIS - topographic
database and application database - often are realized
in the existing applications yet. Due to the actual hard-
and software limitations standard Geographic
Information Systems are separated into some parallel
existing GIS: a vector GIS and a raster archive repre-
senting the topographic databases, a geological and a
Soil information system as two application databases
for example.
693
In order to the increasing hardware capacities
(jukeboxes etc.) and the actual software development
the realization of large integrated hybrid GIS seems to
be possible soon. But on the other hand database
sharing and transaction systems could be of special
interest for GIS because of multidisciplinary users.
This leads to a decentralized concept alternative. In
distributed database architectures it is possible to
handle the data in different local organisations.
Nevertheless the user's interface may look like in
centralized systems (logical centralization).
Decentralized systems give a better system structure
and increase the performance due to parallel possibili-
ties. But it must be pointed out that a complete distri-
buted functionality is not really available in commer-
cial decentralized systems yet.
