A Census of Public OGC Web Services

1
A Census of Public OGC Web Services

• Paul RamseyRefractions Research

2
The Question

• How many OGC Web Servers have been deployed?

3
The Census

• OGC Standards include a fortunate repeated
  pattern
• REQUESTGETCAPABILITIES
• REQUESTCAPABILITIES
• We need a tool that can search the entire
  internet for this particular pattern of
  characters

4
The Census

• Google searches the net by spidering
• Indexes over 8 billion URLs
• Index updated every month
• Provides a SOAP programming API

5
The Census
Search Script
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The Census

• For each Google page
• Does it contain a URL pattern with
  RequestGetCapabilities?
• Can we connect to that URL?
• Does it return XML we can parse?
• Store the URL and XML in our database!
• Extract the WMS layers and store them too!

7
The Database
wms_servers
wms_server_layers
server_idserver_urlxml_capabiltieshostnamecoun
tryroot_tagserver_typeversion
layer_idserver_idlayer_namelayer_titlelayer_ab
stractlayer_bbox
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The Answer
269
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The Missing

• Private servers.
• Servers with no public link to a Capabilities
  document. (Effectively private servers.)
• Servers with a link that does not include
  requestgetcapabilities.(A non-clickable link.)

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Server Types
221 Web Map Servers 22 Web Feature
Servers 18 Web Servers 8 Standard
Errors 269 Open Geospatial Servers
11
Server Types
12
WMS Versions
13
National Participation
14
Another Question

• How many layers are all these WMS servers making
  available?

15
The Answer
8695
16
National ParticipationBy Layer
17
Very Large Servers
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Future Plans

• Monthly Database Refresh
• Automatic Statistics Generation
• Longitudinal Graphs and Trends
• Feed a real Web Registry Server

19
Getting Into

• Create a ltagthyperlinklt/agt to your WM
  Capabilities document on a publicly accessible
  web page.
• Ensure the hyperlink includes the string
  requestgetcapabilities.
• Ensure the hyperlink is live. If you click it in
  a web browser, the XML Capabilities document
  should be returned.

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Why WM Suck

• Hard to find
• Poor metadata
• Slow responses

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How to Make WM Good

• Make them easy to find
• Get into Google!
• Fill out all metadata with good information
• Titles and Abstracts and MetadataURLs
• Make sure they are fast
• Use the coffee test

22
uDig Friday Beers Demo

• After CGDI meetings at PFC
• Refractions ResearchVictoria
• Suite 520 - 1207 DouglasSayward Building

23
Thank You

• pramsey_at_refractions.netwww.refractions.net/ogcsu
  rvey