www.geobeijing.info - 09/07/2008
During the 29th Olympiad and Paralympics in Beijing a corps of over 1.5 million volunteers will provide visitor support. Some tasks, such as giving information on transport and geographical orientation, can be performed by geo-browsers. The authors developed a portal, www.geobeijing.info for guiding visitors to Beijing during the ISPRS Congress and the Olympic Games. The maps are based on Google Maps satellite images, overlaid with additional information.<P>
The portal provides information and links relevant to Beijing, the Olympic Games and the ISPRS Congress. Users can search for streets and hotels, and access related information using side panels with hyperlinks. Venue locations, photos and traffic information are offered for the ISPRS Congress.
The main criterion for layout design was that the portal should be attractive and easy to use. In the present implementation, users are briefly but clearly informed concerning the purpose of the portal and information available. The three columns are based on the Cascading Style Sheet standard (CSS), and styling properties are largely compatible with modern browsers. On the left appear navigation and search capabilities. During map display the right column acts as a side panel which supports easy access to additional information such as venues, streets or hotels, and its content is updated according to the information shown.
We were able to collect plenty of information from internet and literature research. Most geographic data is either in the form of points, lines or polygons. These geometric features are described in OGC’s Simple Feature Specification and supported by Google’s API and that of other vendors. In the Google API many classes, types and events have been defined to represent many features and carry out multiple functions on the map. Some examples are Map2 class and the GlatLng class for points in geographical coordinates. We digitised maps using either professional desktop GIS software (MapInfo Professional) to collect data from scanned maps, or Mashups based on Google’s API, which can export data in a format suited for further processing. In this way we collected point features (points of interest, hotels, and bus and railway stations), linear features (streets, subways, bus lines) and polygon features (Olympic and ISPRS venues). We overlaid more than 1,800 streets onto Google satellite imagery. Each street can be accessed via a name list in the side panel or a search form with AJAX-based auto-completion.
Hotel locations, which are integrated into the map, can be approached in the same way, while photographs and hyperlinks to their websites are shown in a separate window. The side panel enables zooming and panning to Olympic venues such as the National Stadium, the National Aquatics Center, or the Beijing University Gymnasium, while additional information and photographs are displayed in a window which pops up automatically. Venues outside Beijing’s city centre are also accessible, such as the Triathlon Venue at Ming Tomb Reservoir. Using buttons one can ‘jump’ directly from one location to another. ISPRS 2008 Congress venues are also linked to public bus infrastructure information. Points of interest are available through the side panel, and expressways around the city centre are visualised for better orientation.
While the client uses the above technologies, PHP is the server-side programming language for creating dynamic web pages and for database access. MySQL is used as a database management system. The above technologies will boost bringing geographic information to the millions.
- Garrett, J. J., 2005. Ajax: a New Approach to Web Application. Adaptive Path. http://www.adaptivepath.com/publications/essays/archives/000385.php [2008-05-05]
- Purvis, M., Sambells, J., Turner, C., 2006. Beginning Google Maps Applications with PHP and Ajax. Apress, 350 pages, ISBN 1590597079, http://googlemapsbook.com/
- Google Maps API Reference http://code.google.com/apis/maps/documentation/reference.html u
Example of a CSV Encoded String
Road_0001;Aimin_Jie;Road;Polyline;116.376;39.9309;116.376;39.9266;116.376;39.9317;LINESTRING(116.375686 39.931674,116.375683 39.931593,116.375747 39.93026,116.375806 39.926574)