30-05-2013, 12:56 PM
Next Generation Web Mapping
Next Generation.ppt (Size: 6.72 MB / Downloads: 249)
Previous Generation
Client technology
Static map image with single level of detail exposed as flat image file on web page.
User interface features limited to form-based HTML information requests.
Geospatial toolset limited to moving around flat image within single level of detail (pan).
Server technology
Map images generated on-the-fly and temporarily stored as a single image file. Changes in level of detail required generating a new map image.
Client-server communication through complex HTTPRequest strings passed to map server through web forms.
Limited spatial capabilities accessed through restrictive and proprietary XML variants (ArcXML and GML).
ArcIMS 4.0, Web Mapping Server (WMS).
NextGen Map Applications
New client technologies will provide multiple users with an experience very similar to a traditional desktop client.
New server-side approaches will provide for extremely fast data transfers of map imagery for both 2D and 3D client interfaces.
New geospatial web services will provide for a very large geospatial toolset that could be consumed by many different client technologies in whatever combination desired by the individual user.
Service Oriented Architecture
There is no widely-agreed upon definition of service-oriented architecture (SOA) other than its literal translation that it is an architecture that relies on service-orientation as its fundamental design principle. Service-orientation describes an architecture that uses loosely coupled services to support the requirements of business processes and users. Resources on a network in an SOA environment are made available as independent services that can be accessed without knowledge of their underlying platform implementation.
Benefits of SOA
Allows for distributed, web-based mapping applications that can be rapidly engineered for each unique need.
Accessible to the widest possible user-base with the smallest application footprint possible on the local computer.
Connects light-weight mapping client applications to relevant geospatial and legacy data stores.
Leverage server-side geoprocessing tools for distributed analysis.
The North Orkney Historic Population Project
Examine changes in demography, economy, settlement, and land-use in the north Orkney Islands (Westray, Papa Westray, Faray, Eday, Sanday, and North Ronaldsay).
Period of interest is c. AD 1735-2000, which witnessed two transition trends:
From traditional subsistence production based on small-scale farming and fishing to modern system of beef production for external markets.
From sustainable demographic regime with limited migration to system with substantial out-migration, depopulation, and population aging.
Project intended to study the spatial relationship between the factors in an attempt to better understand the forces of demographic change in a relatively contained population.
Project Assumptions
New models of demographic change should be explicitly spatial in nature.
“Homeostatic demographic regimes” (a population in equilibrium sorted by clusters of habitats from which necessary resources are drawn) have both temporal and spatial dimensions.
Modern demographic change always involves a significant reorganization of population across space.
Remotely sensed imagery should provide new perspectives on the environment of the study population.
The northern islands of Orkney are virtually treeless, providing near-optimal conditions for the use of remote sensing as an environmental and archaeological survey method.