Tech Primer

GeoWeb

GeoWeb refers to the merger of geographical location-based information with abstract data, currently dominating the Internet. The GeoWeb infrastructure provides an open, global, and scalable infrastructure for discovering information on the Internet associated with a specific location by its latitude and longitude. GeoWeb enables search based on locations instead of keywords as is the case today. Some of the technologies that have enabled GeoWeb are Google Earth, Windows Live Local, Yahoo Maps, and NASA World Wind. One of the unique attributes of a geospatial platform is its ability to aggregate a multitude public and private geographic data sets, providing access to data from government agencies, industry and the general public.

Features

There are numerous ways to browse GeoWeb, one of them is using a 3D representation of the Earth. Users can navigate in real time to locate and view relevant information. NASA and other organizations have planetary science databases representing data from thousands of satellites orbiting the earth, and from dozens of missions to other planets. A geobrowser interface is designed to provide convenient access to all kinds of geographically referenced information.

XML-based metadata records are distributed across the GeoWeb using the existing Domain Name System (DNS). Each metadata record describes an object, its geographic location, and links to actual data. Clients query the GeoWeb to discover relevant metadata and use Web-based or peer-to-peer communications to retrieve the actual data.

Technology behind GeoWeb

The GeoWeb infrastructure distributes vast geographic databases across millions of servers around the globe. The structure is massively scalable and builds on the existing Domain Name System in order to encode a hierarchical latitude/longitude location using a standard Internet URL.

GeoWeb setup divides the planet into a hierarchy of web servers. In the hierarchy each server has a DNS name representing a given geographic area of the earth, termed as a cell. Clients can immediately determine which server to query by using the DNS names representing the geographic service area and therefore the name of the global server is not required. The server is responsible for all metadata within the range and keeps a track of the data that lies within its domain.

For further information, visit:www.esri.com/library/whitepapers/pdfs/geoweb.pdf

— Garima Grover
grover_garima@hotmail.com