1、Res. ITU-R 40-2 1 RESOLUTION ITU-R 40-2*Worldwide databases of terrain height and surface features (1997-2003-2007) The ITU Radiocommunication Assembly, considering a) that there is a requirement for planning purposes for improved worldwide methods of predicting field strength which take account of
2、terrain height and surface features (including ground cover such as buildings, vegetation, etc.); b) that digital maps of terrain height are now becoming widely available with various data formats and resolutions, and that maps with 3 arc second resolution in latitude and longitude are available on
3、a global basis. Digital maps with better resolution are becoming available nationally; c) that propagation predictions may be improved by the inclusion of more detailed information on terrain heights and surface features; d) that the availability of digital maps of terrain height and surface feature
4、s would be of considerable benefit to developing countries in the planning of their existing and newly introduced services; e) that the use of terrain height data may optimize technical studies; f) that Radiocommunication Study Group 3 has an active work programme concerning the development of impro
5、ved prediction methods, resolves 1 that a terrain database with a 1 arc second horizontal resolution in latitude and longitude is more suitable for worldwide methods of propagation prediction in the frequency range from 30 MHz to 60 GHz; 2 that administrations should review the terrain data availabl
6、e in this format, and should provide additional data so as to complete the worldwide extent of the database; 3 that administrations should be encouraged to make these terrain databases freely available for ITU purposes; 4 that administrations should encourage organizations involved in the production
7、 of terrain maps to produce databases of terrain height and surface features with a resolution equal to, or better than, 1 arc second for areas for which such data do not exist; 5 that administrations are encouraged to use terrain height for radio propagation prediction; 6 that terrain heights shoul
8、d be used according to ITU-R Recommendations. _ _ *This Resolution should be brought to the attention of Radiocommunication Study Group 1 for consideration of the use of a terrain database for national spectrum management purposes. This Resolution should also be brought to the attention of the Telecommunication Development Sector.
