GRAPHIC BASE OF CARTOGRAPHIC DATA
T.V.Vereshchaka, I.I.Lonsky, A.S. Vakhtanov
Creation of cartographic data base gives to the user a lot of advantages: Simplicity and speed of access to cartographical data of spatial and attributive character, an opportunity of binding to spatial data of various sort of descriptive and analytical information.
By way of theoretical experimental researches we have developed and realized a local variant of a database by means of Microsoft Visual FoxPro 6.0. There are determained both structure of all database, and structure of tables entering into it. The variant of relational base is realized by means of indexing introduction. By virtue of necessity of a plenty of the information input the form of data input-output contains the bookmarks, allowing solving this problem and creating a number of convenience to the persons who are carrying out support of a maps database.
Now work on creation of the maps distributed database of which are available in fund of storage at the MIIGAiK cartography chair is conducted. For this purpose the local network with a powerful server and a number of cartographic data base support client places is organized. The base will contain graphic and attributive data on map sheet. Graphic results will be presented by raster images of maps sheets and corners coordinates of a raster in geographical system of coordinates. Graphic representations are displayed at the monitor in the form of maps sheets on a geographical grid of parallels and meridians on globe in one of necessary projections. Change of a projection is provided. For orientation the image will be added with borders of the states, areas and administrative centres. Attributive data will be presented as the basic data for a map sheet: Its type, name, scale, projection, publishing house, authors, editors, quantity of available copies, etc.
The database will be arranged on a separate server, the user access to it to come true through the Web-interface (Appachy server and html, PHP 5.0, Visual Java means), representing a graphic window with frameworks of sheets of maps, navigation tools of data search. The attributive information will be brought out in a separate window.
Researches lean on the earlier developed and realized electronic catalogue (for a foreshortening of the attributive information).
realization of the database operation free software products will be mainly used. The basic
product visualizing graphic data through Web-interface (UNM Mapserver) is a
development of the
Graphic data in Mapserver are by default stored in files of SHP – ESRI format shapefiles, but support of other formats (Mapinfo, DXF, Microstation, etc.) can be realized or storage of vectorial data in tables by means of PostgreSQL-PostGIS sheaf can be organized. Raster data will be stored in GeoTiff or Jpeg2000 format. Filling of a graphic database is supposed to be executed by means of geoinformation systems GRASS or Microstation.