Česká verze této stránky

Land Survey Office performs the administration of geodetic control of the Czech Republic and decides about localization, transfer or removal of survey marks of the fundamental ground control in accordance with the Act Nr. 359/1992, Coll., in later wording. Land Survey Office performs simultaneously land survey works for maintenance and verification of the state borders according to § 3a of the Act. Nr.107/1994 Coll. Land surveying activities are realized based on the agreement with the administrator of the state boundary documentation that is the Ministry of Interior of the CR.

Classic geodetic control is represented by geodetic control fields comprising monumented geodetic points with known coordinates in mandatory reference systems. The points of fundamental geodetic control are set, maintained and renewed by the department of geodetic control. It carries out the maintenance and renewal of chosen points of following networks:

• Czech state triangulation network (ČSTS
• Czech state levelling network (ČSNS) of 1^st to 3^rd order
• Special levelling networks (ZNS)
• Fundamental geodynamic network of the CR (ZGS)
• Czech gravimetric network (ČGS)

Modern geodetic control is represented by the network of reference stations enabling signal reception from global navigation satellite systems (GNSS) that are in permanent operation (that is why other names for them are permanent stations).Land Survey Office operates the Network of permanent stations GNSS of the Czech Republic (CZEPOS) representing modern spatial geodetic control at the territory of the CR. The network comprises GNSS stations of known coordinates in binding reference systems regularly spread at the whole territory of the CR. The stations perform permanent GPS observations, which are in the form of correction data provided to the users.
 

Land surveying activities, their range as well as factual content is different for state borders with individual states and such as strictly subordinated to tasks and provisions of international contracts about state borders so as to their documentation administered solely in cooperation of both international partners. Processing of documents regarding the marking maintenance, state borders inspection and updating of the borders documentation is governed and coordinated by the international border commission represented by particular states representatives. Till 90´ of the last century the borders documentation including the border maps was administered and updated mostly in original graphical form. From the Czech side no initiative was realized to connect the state borders (meant border marks and non-marked break points of state borders) to the national reference coordinate system. Present time is characterized as the period of transition and updating of border documentation works from the graphical to digital form so as determination of positional coordinates of all break points of state borders.

Databases of geodetic control (DBP) are administered by the department of geodetic control in the Land Survey Office. There are:

- trigonometric and densification points from the territory of the Czech Republic with overlap to the territories of neighbouring countries, it is more than 69 thousands centres of trigonometric points (TB) and densification points (ZhB) and more associated points. Damaged points and all changes of coordinates are administered in the DBP. The associated points are stored only with bearing from south counted grid and length, coordinates are calculated at the output of the database. The points of minor control (PPBP) administered in the frame of Information system of the cadastre of real estate (ISKN) have been published in the DBP since 2008 as well. The administration of TB is in responsibility of the Land Survey Office so as the continuous update of DBP. Administration of ZhB and PPBP points is in responsibility of territorially competent cadastral offices.

- levelling points from the territory of the Czech Republic; it is 12 vertical datum points (ZNB), 16 thousand points of the first order of the Czech state levelling network (ČSNS), 20 thousand points of the second order and 47 thousand points of the third order. DBP has been step by step filled since 2006 also with the points of the fourth order and points of the surface levelling (PNS). Administration of ZNB and points of first to third order is in responsibility of the Land Survey Office. Administration of points of fourth order and PNS points is in responsibility of territorially competent cadastral offices.

- gravity points from the territory of the Czech Republic, it is 400 points of the Czech gravity network that are administered in the Land Survey Office.

Land Survey Office provides data from the DBP via internet. Users can get free access to the geodetic data about ground control points, which were accessible solely in printed version till 2004 in particular departments of point administration of the Land Survey Office and in territorially competent cadastral offices for a fee stated in then price list.
 

Point selection from the database is possible via localization units: point number, map sheet of the Basic map of the CR 1: 50 000 or State map 1: 5000. The point surroundings is defined by coordinates or by graphical map cut-out with point depiction. Data form the Database of ground control points is also accessible in the frame of ČÚZK Geoportal via free viewing service WMS – Bodová pole . The service offering queries for descriptive attributes of geodetic data can be used in the application Geoviewer or in the frame of map window on the introductory website of the ČÚZK Geoportal as well.

The geodetic control database can be also accessed using the Download service WFS - Geodetic controls.

Database of ground control points won the 1st place in the competition Technical work of the year 2004, which was held by the Chamber of land surveyors and cartographers  . Geodetic data in written form can be provided for a fee by the department of point administration and services of the geodetic control of the Land Survey Office.

(room 431, telephone 284 041 534, fax 284 041 625, eMAIL: dbp@cuzk.cz.)