The document discusses Proxy4OWS, an OGC OWS proxy that transforms Web Coverage Service (WCS), Web Feature Service (WFS), and Web Map Service (WMS) to Web Map Service (WMS) in order to display large geospatial datasets in web environments. It summarizes the capabilities of Proxy4OWS for each service type and discusses caching functions, examples, links, and areas for future development.

1. Introduction
Proxy4OWS
Links
Outlook
Summary
Proxy4OWS
a ˇ
J´chym Cepick´1
y
1 Help Service - Remote Sensing
http://bnhelp.cz
jachym@bnhelp.cz
FOSS4G-CEE, 2012
Jachym Cepicky Proxy4OWS

2. Introduction
Proxy4OWS
Links
Outlook
Summary
Outline
1 Introduction
2 Proxy4OWS
WCS
WFS
WMS
3 Outlook
Jachym Cepicky Proxy4OWS

3. Introduction
Proxy4OWS
Links
Outlook
Summary
About
Visualize and work with large vector data and raster data in
the web environment
OGC WFS, WCS (WMS) → WMS
Jachym Cepicky Proxy4OWS

4. Introduction
Proxy4OWS
Links
Outlook
Summary
The problem of displaying large GIS datasets
The problem
Google limit up to 1000 vector features
Problem displaying large vector data (cadaster)
GeoTIFF - not supported by browsers
Unspported coordinate reference systems
Jachym Cepicky Proxy4OWS

5. Introduction
Proxy4OWS WCS
Links WFS
Outlook WMS
Summary
Proxy4OWS
Transforms WCS, WFS (and WMS) to OGC WMS
Client deals with raster images
There is still possibility to access original service type
(e.g. WFS → WFS)
There is possibility to access original service URL
Jachym Cepicky Proxy4OWS

6. Introduction
Proxy4OWS WCS
Links WFS
Outlook WMS
Summary
GetCapabilities
Standard GetCapabilities request with two additional parameters
1 owsService=URL url to desired service
2 owsType=SERVICE TYPE like WFS, WCS or WMS
Server creates temporary cache directory for particular service,
starts to generate mapfile.
Jachym Cepicky Proxy4OWS

7. Introduction
Proxy4OWS WCS
Links WFS
Outlook WMS
Summary
Outline
1 Introduction
2 Proxy4OWS
WCS
WFS
WMS
3 Outlook
Jachym Cepicky Proxy4OWS

8. Introduction
Proxy4OWS WCS
Links WFS
Outlook WMS
Summary
Web Coverage Service
WCS
OGC WCS layers are configured using GDAL WCS format
http://gdal.org/frmt_wcs.html
No caching is provided
Jachym Cepicky Proxy4OWS

9. Introduction
Proxy4OWS WCS
Links WFS
Outlook WMS
Summary
Outline
1 Introduction
2 Proxy4OWS
WCS
WFS
WMS
3 Outlook
Jachym Cepicky Proxy4OWS

10. Introduction
Proxy4OWS WCS
Links WFS
Outlook WMS
Summary
Web Feature Service
WFS
WFS was implemented natively using OWSLib
http://sourceforge.net/apps/trac/owslib/wiki Axis
order and filter parameter support in MapServer or OGR
Simple caching is provided (for BBOX, not for FILTER)
Data are downloaded (with OWSLib) localy and MapServer
LAYER is configured with this local file
Jachym Cepicky Proxy4OWS

11. Introduction
Proxy4OWS WCS
Links WFS
Outlook WMS
Summary
Web Feature Service
WFS
WFS was implemented natively using OWSLib
http://sourceforge.net/apps/trac/owslib/wiki Axis
order and filter parameter support in MapServer or OGR
Simple caching is provided (for BBOX, not for FILTER)
Data are downloaded (with OWSLib) localy and MapServer
LAYER is configured with this local file
Jachym Cepicky Proxy4OWS

12. Introduction
Proxy4OWS WCS
Links WFS
Outlook WMS
Summary
Outline
1 Introduction
2 Proxy4OWS
WCS
WFS
WMS
3 Outlook
Jachym Cepicky Proxy4OWS

13. Introduction
Proxy4OWS WCS
Links WFS
Outlook WMS
Summary
Web Map Service
WMS
Used for unsupported CRSs
No caching
Data are disturbed, but visible
Jachym Cepicky Proxy4OWS

14. Introduction
Proxy4OWS WCS
Links WFS
Outlook WMS
Summary
Proxy4OWS Schema
Jachym Cepicky Proxy4OWS

15. Introduction
Proxy4OWS WCS
Links WFS
Outlook WMS
Summary
Capabilities Schema
Jachym Cepicky Proxy4OWS

16. Introduction
Proxy4OWS WCS
Links WFS
Outlook WMS
Summary
Examples
WFS http://briseide.ccss.cz/map/ with
http://bnhelp.cz/ows/crwfs WFS service
WMS http://habitats.cz/view with
http://bnhelp.cz/ows/crtopo WMS service
(layer Sidla in WGS 84)
Client http://hslayers.org HSLayers.Layer.WCS,
HSLayers.Layer.WMS, HSLayers.Layer.WMSWarped
Jachym Cepicky Proxy4OWS

17. Introduction
Proxy4OWS WCS
Links WFS
Outlook WMS
Summary
Examples
Jachym Cepicky Proxy4OWS

18. Introduction
Proxy4OWS
Links
Outlook
Summary
Links
http://proxy4ows.org
http://redmine.ccss.cz/projects/hslayers
git://git.ccss.cz/hsrs/owsproxy.git
Jachym Cepicky Proxy4OWS

19. Introduction
Proxy4OWS
Links
Outlook
Summary
Robustness
SLD
Caching
Jachym Cepicky Proxy4OWS

20. Introduction
Proxy4OWS
Links
Outlook
Summary
Summary
Proxy4OWS python-based server-side OGC OWS proxy.
Transforms OGC OWS services to OGC WMS.
Jachym Cepicky Proxy4OWS

21. Introduction
Proxy4OWS
Links
Outlook
Summary
Questions?
Jachym Cepicky Proxy4OWS