1. Subject and field of application of the standard
The subject of this standard is the conceptual model of the digital base map (hereafter referred as DAT) encompassing the aims of Hungary's surveying large scale maps.
DAT is a computer-aided true to form representation - with content details needed for expressing of mutual selection and carried out from time to time by generalisation - of data of parcels, artificial and natural Earth's surface configurations according to the requirements fixed in this standard.
This standard aims to determine the sphere of object types to be represented, of their geometrical data, of content features and of data quality and relation characteristics, the principle of their sorting into hierarchy as well. The conceptual model defines also database at the same time.
DAT is part of the Uniform National Map System (EOTR). It is compatible from above with former surveying large scale base maps at scales 1:1000 - 1:4000 from the point of view of information technology, content and data quality.
The DAT serves as a basis and junction surface for surveys of real estate registration, local government, public utilities, transportation, water resources and other branches and records, as well as for LIS systems requiring large scale bases.
This standard lays the foundations of the regulations of the physical data model, data exchange model, data acquisition model and related legal frames in the subject covered by it.
The DAT described in this standard is build up in space, time and as for details of content according to the principle of gradience.