Ordnance Survey MasterMap (*.gml;*.gz)

Ordnance Survey MasterMap is a large scale vector dataset consisting of points, LineString items, Polygons and text. Scale of datasets ranges from 1:1,250 in urban areas to 1:2,500 and 1:10,000 in rural areas. Data is supplied as geographic 'chunks' rather than tiles so that features on the edges of tiles are not broken.

SIS Desktop 9 can read both the GML and the compressed Gzip files (the latter without any performance loss).This means that data can stay in its compressed format, as *.gz files, and save storage space.

Data can be read directly from flat files, or from a variety of database formats once stored using the Cadcorp Ordnance Survey MasterMap Manager.

Data supplied from the Ordnance Survey will either be a full supply containing all mapping detail or a Change Only Update (COU) file containing just the changes since your last supply.

Import Configuration:

Go to Add Overlay > Files, select the required file in the File Browser dialog and click on Configure... to get topological and attribute configuration options. 

Select the option to skip various attributes; skipping attributes ensures they do not appear in the items schema or attributes thus improving processig speed.

The settings chosen in this process are retained and used on any subsequent Ordnance Survey MasterMap data viewed. 

Note: See also: www.ordnancesurvey.co.uk


  • Cadcorp SIS Desktop
  • Cadcorp SIS Desktop Express
  • Cadcorp SIS ActiveX Modeller
  • Cadcorp SIS ActiveX Manager
  • Cadcorp SIS ActiveX Viewer
  • Cadcorp GeognoSIS