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— Register of Cadastre of Real Estates as a part of the
ISZK, the main identifier of which is the parcel and its
centroid. It ensures the uniform localization of territorial
phenomena. It describes phenomena related to space
structures and represents them as a graphic image. The
miscellaneousness of graphic phenomena is characterized by
their descriptive and graphic components and integrates
them together through a set of identifiers (names, codes,
numeral expressions etc.). As a decentralized (local) level of
territorially orientated information systems is created, par-
allel with the SIS CR, and that is presented by models of
district and municipal offices, it serves as a source layer for
all territorially orientated information systems of other
branches, state administration as well as for map products
in the CR.
2.2 ISZK databases
The Information System of Surveying, Mapping and Cadas-
tre (ISZK) is based on the same conception as the SIS CR,
i.e. it has two levels - the central and the local ones. It will
be created by databases of three subsystems [1], that will be
interconnected, namely through the uniform database system
and the software environment. These subsystems are:
1. Subsystem of Basic Control (Czech abbr. SZBP),
consisting of spatial data of basic trigonometrical, levelling,
and gravimetrical networks of fixed points covering the
entire state territory. By these data a uniform system of
spatial coordinates and also a uniform projection system on
the state territory can be defined.
2. Subsystem of (digital) Cadastre of Real Estates (Czech
abbr. SKN) which is formed by two interconnected informa-
tion files:
- Survey Information File (Czech abbr. SGI),
- Descriptive Information File (Czech abbr. SPI).
3. Subsystem of Topographic Information (Czech abbr.
STI) which contains spatial data of digital medium scale
maps on the state territory as a basic (source) topographic
database with enforcement of possible connections to above
mentioned subsystems.
The simultaneous interconnection of arising databases
of individual subsystems is ensured by MS DOS operating
system and dBASE IV database system environment, of
SZBP already by ORACLE. The consecutive ISZK building
assumes above all utilization of available data funds pro-
vided by digital surveying, photogrammetric and cartometric
methods. By means of modern interactive technologies and
data analysis technologies on the computer graphic systems
and attached database installations these acquired data
could be interpreted in a uniform way, as well as classified,
vectorized and processed. At the same time the main
purpose of the central database is to ensure (fulfil) the data
coincidence with local nets LAN-PC databases, to yield
aggregated information of the SPI SKN, as well as SZBP,
STI, mainly for the SIS CR level, and check and archive the
' SPI data.
717
Local databases ensure the primary SKN actualization
(management) in cadastral offices including information
which enable generation of actualizing sentences for the
central database. Further task of local databases is a suc-
cessive creation and management of the Digital Cadastral
Map (Czech abbr. DKM) and giving information about
SZBP, SKN and STI. (Tab. 1).
2.3 Geodetic control
Within the framework of the SZBP there has been solved
during the project solution till now the creation, manage-
ment and utilization of the Horizontal and Vertical Basic
Controls including automated topography of individual
points [3]. Furthermore, the programs for determination of
astronomic orientation by measurements to the Polar star
and to the Sun [4] were processed as a part of the SZBP. In
the VÓGTK there were also completed computing programs
that will enable the mutual transformation of coordinates of
the State Coordinate System of the CR (S-JTSK) into the
European Geocentric Coordinate System (ETRF) with such
accuracy level as demanded by the international committee
CERCO (Comité Européen des Responsables de la Carto-
graphie Officielle) [5]. It is concerned with processing of
results of actual observation techniques utilizing artificial
satellites based on the GPS (Global Positioning System)
application. The relevant software package and technologies
are introduced into operation in the Office of Surveying and
Mapping which acts as the manager of these data. At the
same time a relatively independent database from GPS
observations was solved. This database will serve for
registration, distribution and analyses of data acquired with
GPS apparatus within the framework of actualization and
maintenance of the basic control (Czech abbr. ZBP). The
database will be connected on the central database level of
selected 177 points, so called "Zero order network of the
CR" [6].
2.4 Digitization of the cadastre of real estates
The goal of the SKN solution was to create prerequisities
for creation and management of the source database of both
graphical and databasic (attributive) information. Spatial
units and spatial data are localized in the uniform State
Coordinate System JTSK. Spatial data are opened up in
a common precisely defined spatial unit, without exception
structurizable and identifiable on the entire state territory.
It deals with cadastral district. For data transmission
(graphical and databasic) the countrywide standardized
interchange formats have been advertised [7].
The SKN is based on a common database conception of
both survey information file (SGI - digital cadastral map -
DKM) and descriptive information file (SPI). The technol-
ogy of management and yielding of information from the
Cadastre of Real Estates in local networks at cadastral
offices respects the data (graphical and databasic) storage
in a server, different level of data access rights, as well as
the data protection and automated outputs in cadastral
territories, where the DKM will be processed and main-
tained.
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996
