Operational Review #5
- Describe in a sentence or two your overall operational experience related to WMS. (e.g., scientific visualization; geospatial visualization, etc). What kinds of WMS servers and/or clients do you have experience with? (e.g., commercial products, open source, or independent implementations, please provide as much detail as possible).
- The University of Minnesota, Department of Forest Resources uses UMN MapServer as WMS servers and clients in prototype and demo applications for natural resource management and general web mapping applications. We typically use WMS as client layers in GIS and web mapping, strictly for visualization purposes. Our use of WMS servers is limited to demonstrations and educational purposes.
- In addition to UMN MapServer, we also use WMS-compliant applications from USGS, NASA, NOAA, Refractions Research, Cubewerx, Intergraph, ESRI, and others.
- What types of applications do you use WMS servers/clients for? Are they suitable for your applications? (e.g., Do they work well with the data types and data manipulations in your application?)
- While WMS services provide map representation of both vector and raster datasets, we generally showcase the WMS capabilities of MapServer using the latter. MapServer also supports the WFS specification and we use vector datasets to demonstrate that capability. This is not a knack against WMS as it is a very efficient way of delivering maps over the Internet.
- Why do you choose to use WMS over other protocols for your applications?
- One of the biggest benefits of WMS is that it provides vendor-independent maps and it does this with minimal penalty on the server.
- Are the WMS systems easy to use? (e.g., Is it hard to learn how to use WMS systems?)
- WMS clients and servers are very easy to setup and implement using MapServer. It uses three protocols, one of which is used to determine a servers capabilities (GetCapabilities) and the other two are used for retrieving the maps (GetMap) and associated attribute information (GetFeatureInfo). Even in a very simple system such as MapServer, it is very easy to implement a WMS service.
- Does the performance of the WMS systems you have experienced meet your requirements? (e.g., Does it take a long time to access/view data in WMS systems?)
- Yes. The amount of time it takes to process a WMS request in MapServer isnt noticeably different than using MapServers native protocol. This is, of course, dependent on many factors with spatial extents and resolution potentially affecting the time a request is processed and returned. Hardware and how one stores the raw data will undoubtedly affect the performance of a WMS system.
- What operational challenges do the WMS systems present? (e.g., Does it require advanced processing power, large amounts of memory, complex configuration, etc.? Are the systems easy to deploy and maintain?)
- The challenges of setting up a WMS system using MapServer for demonstrations arent any more different or difficult than implementing a system that uses the native protocols. It may be different for systems where there is high volume of WMS requests.
- How well do the WMS systems scale to large numbers of simultaneous users, or to large datasets?
- We dont have direct experience in this regard but MapServer is being used by government agencies and large companies around the world to serve WMS maps.
- Can you provide information on user statistics of your WMS systems? How have the user statistics changed over time?
- We dont have reliable statistical data for our WMS systems as they are used mostly for demonstration purposes.