The GRAIL Map Data Page

Geographic Roadway Application for Information Location

The following are the mapping data files that GRAIL uses in order to display the backgrounds on the maps that are presented at the top of the GRAIL report. This data is not essential for GRAIL to run, but it vastly improves the appearance of the GRAIL pages. The following data files are very large; they will require great amounts of download time.

The Marplot data will allow GRAIL to display background information like city and county boundaries, major and minor roads, rivers, lakes, railroads, etc. Although GRAIL can function without Marplot data, there are certain features of GRAIL that rely on the Marplots. So if you have to choose Marplots or BEMs, choose Marplots.

The BEM data allows GRAIL to display terrain data. GRAIL functions just fine without BEM data, but if you can make room for it, the appearance of the is greatly enhanced by the use of BEMs. Because the data size is so vast for BEMs, they have been split into two compressed download files, one for the east side of the state, and one for the west side of the state.

The data is compressed as "zip" files. They will need a data uncompression program such as PKUNZIP or WINZIP to make them useful. When uncompressing the 'marplot' data care must be taken to assure that the directory structure that is encoded in the compressed "zip" file is preserved upon data uncompression.

For your information, this data is a different format of freely available data from both the U.S. Census Bureau and the U.S. Geological Survey. The marplot files are a different version of the TIGER/Line 1994 data. This data should be compatible (with slight sequence differences) to the marplot files that are read by the Landview II and III products developed by U.S. Environmental Protection Agency, Chemical Emergency Preparedness and Prevention Office. The BEM (Binary Elevation Model) files are just a binary version of the 1:250,000 scale DEM (Digital Elevation Model) files available through the U.S. Geological Survey. They were converted to binary format to conserve space and save time loading the fairly large data volumes into memory.

GRAIL Map Data Download Area

Navigate the GRAIL Pages

	Go Configure!	Latest GRAIL executable and configuration files.
	Datamania!	Get the current Roadway/Roadside Characteristics data flat files.
	Mapster!	Get the current mapping data files.
	Gotta Have a Copy!	How to install GRAIL.
	The GRAIL Page	Go to the Main GRAIL page.