Specifications

Tutorial 2: Working with Data 37
Data Access Protocol (DAP)
DAP is a technology that enables efficient transfer of high volume spatial data from a
designated DAP data server to a DAP client via the Internet or an Intranet. There are two
types of DAP clients, a thick client (a desktop software application) and a thin client (web
browser).
Oasis montaj, MapInfo and ArcGIS are thick DAP client software applications. Thick
client applications enable you to download and save the actual data to your hard drive, so
you can use the data in Oasis montaj or any other GIS or spatial data processing program.
Thin clients, like Geosoft’s DAP Data Explorer use a web browser to browse, view and
extract data from a DAP server. Visit www.geodap.com/map/ and see how it works!
Geosoft’s DAP capability enables users of both the free Viewer and licensed applications
to access Geosoft’s public DAP server. This server contains global topographic, coastline
and river data as well as magnetic and gravity data for North America and Australia.
These data sets (grid and point data) can be used to create sample maps in Oasis montaj
and to learn about the newest technology for accessing high volume data via the Internet.
Additional public access DAP servers are expected to go online soon, for more
information visit: www.geodap.com/map/
DAP’s main features include:
• Large Volume Data Transfer: DAP technology handles the efficient transfer of
very high-volume data, and its associated metadata, through a streaming
technology.
• Spatially Aware: DAP is spatially aware, enabling user-specified spatial querying
and retrieval.
• Ready-to-use Data: DAP provides localized data that matches your current Oasis
montaj map window and projection information.
• Safe and Efficient Data Transfer: DAP data transfer technology provides direct
DAP client/server communication enabling the transfer of compressed data that
maintains original data integrity.
TO ACCESS THE DAP SERVER:
Data on Geosoft’s DAP server can be accessed through the Oasis montaj DAP menu.
Once connection to a DAP server has been established the server will determine what grid
data matches the data view of your map. You will then be presented with a list of data that
is available to be downloaded and displayed on your map.
1. On the DAP menu, click New Map. The Data range to map dialog is displayed.