Mastermap Styling
With EDINA preparing OS Mastermap data for general distribution as part of Digimap, one of my colleagues has become an early adopter for trialling purposes. Whilst I have come across Mastermap in various guises, this was the first time I had seen the whole processing side up close. My colleague downloaded a couple of layers for a 5×5km area which came to over 200Mb. The first problem was loading it in to ArcMap which is one of the least standards compliant GIS packages around (although this might well be coming in v9.2). A trip over to ESRI UK and a download of MapManager 9 allowed the conversion of the OS GML into a geodatabase. Mastermap then loaded fine, although with default ESRI symbolisation. A lot of digging and we finally came across a style file that symbolises the Mastermap data in the same fashion as the default OS styling (and pleasant enough it is too). Its worth noting that you can get a free OS Mastermap GML Viewer from Snowflake Software.
We then downloaded all layers (although no imagery) for a 5×5km area and, 2-hours later, MapManager produced a 750Mb geodatabase. Hmmm, some planning ahead me-thinks. This is clearly a big headache for EDINA (it took about 6-hours for the data request to be processed, rather than the 2-3 minutes for LandLine), hence the need for testing!