FYI: press release: OGC SEEKS INPUT ON WEB MAPPING STANDARD
Stephen Lime
steve.lime at dnr.state.mn.us
Tue Dec 14 12:16:10 PST 1999
I'd like hear what folks involved with the OGC think about these proposed
standards and whether or not the MapServer should strive to support them.
I've skimmed the rfc's and in many cases the MapServer could easily be
extended to support them. I do have concerns about things like layer
symbolization and annotation especially with regards to label collisions. Stick
maps are not what I'd call progress given what might be possible within an
individual system. The earthquake mapping MapScript demo shows what can
happen when an app is dependent on remote data. I shudder at the thought
of trying to tie remote datasets of any reasonable size into a robust "public"
application. GML may well be suited to non-realtime exchange of geodata
but seems a bit bloated (ascii + xml tags) for high performance apps. Will GML
be well suited to streaming - an implementation question? Still, good topics
to discuss and possibly move forward on within the context of the MapServer.
Steve
Stephen Lime
Internet Applications Analyst
Minnesota DNR
500 Lafayette Road
St. Paul, MN 55155
651-297-2937
>>> "Brent Fraser" <bfraser at geoanalytic.com> 12/14/99 01:14PM >>>
MapServers,
I know some have seen this press release, but for
those not in the loop, here it is...
Brent Fraser
GeoAnalytic Inc.
1150 , 633 - 6th Avenue SW Calgary, AB T2P 2Y5
Tel: (403)213-2700 Fax: (403)213-2707
bfraser at geoanalytic.com
www.geoanalytic.com
=============================================
OGC SEEKS INPUT ON WEB MAPPING STANDARD
Wayland, MA, USA, December 13, 1999: The Open GIS Consortium,
Inc. (OGC) today issued Requests for Comment on its pending
OpenGIS Web Map Server Interface Specification and OpenGIS
Geography Markup Language (GML) Specification.
The OpenGIS Web Map Server Interface Specification provides a
set of open protocols that will make it possible for users of
ordinary web browsers to obtain and automatically overlay "map
layers" of the same geographic region, where each layer is a
"view" into geographic data potentially held by a different
web server. Map servers can be from different vendors, and
they can vary widely in terms of processing capabilities and
data type (including multiple vector and raster types). The
three protocols are relatively simple, and it is not difficult
in most cases to add them to data servers. GetCapabilities
provides information about what a server can do. GetMap gets
maps, which might be georeferenced images (such as JPEG and
PNG), simple display graphics (such as SVG or WebCGM), or more
universally displayable "picture element" data (Simple
Features XML, also known as GML). GetFeature_info provides
information about features, so that users can query to get
attributes of specific geographic features in a map layer.
GML is a method for encoding OpenGIS Simple Features (basic
vector-based geographic data) in XML. XSLT "stylesheets" can
then be used to render this "smart data" in
application-specific ways. The GML draft document will be
submitted to W3C as a Note.
In the OpenGIS Web Mapping Testbed, the Web Map Server was
used with catalog services defined in the OpenGIS Catalog
Services Specification, which provides a common architecture
for online automated directories or registries of web-based
geospatial data and geoprocessing services, rather like
"spatial search engines."
As vendors implement these open standards in software, and as
online geodata suppliers make their data available, web users
will easily find, view, overlay, and combine different
thematic maps for a given region.
Geospatial data includes digital maps (including individual
map elements such as roads, lakes and political boundaries),
Earth images, and database records with street addresses or
other fields that indicate physical location. Much geospatial
data is currently available on the web, but users must posses
considerable expertise and special geographic information
system (GIS) software to overlay or otherwise combine
different "map layers" of the same geographic region. Now,
consensus among GIS software vendors in OGC has made it
possible for such overlays and combinations of complex and
essentially different kinds of geographic information to
happen automatically over the Internet, despite differences
in the vendors' geographic data storage, analysis, and
display systems.
The OpenGIS Technical Document 99-077 titled, "Web Map Server
Interface Specification" was submitted by BBN Technologies
(Cambridge MA), Cadcorp Ltd. (UK), CubeWerx Inc. (Canada),
Ionic Software s.a. (Belgium), Laser-Scan Ltd. (UK), SICAD
Geomatics GmbH & Co. oHG. (Germany), Social Change Online Pty
Ltd. (Australia), and the US Army Engineer Research and
Development Center (Alexandria, VA). The OpenGIS Technical
Document 99-082r1 titled "Geography Markup Language (GML)"
was submitted by Galdos Systems, Inc. (Canada), Oracle Corp.
(Redwood Shores, CA), MapInfo Corp. (Troy, NY), Compusult, Ltd
(Canada), and CubeWerx (Canada). Both documents are available
for comment at http://www.opengis.org/techno/request.htm.
After the OGC Technical Committee reviews and incorporates
comments, these specifications are likely to be formally
adopted (as a single specification) at the OGC Technical
Committee and Management Committee meetings to be held in
Vancouver, BC in February, 2000.
OGC is an international, not-for-profit organization working
toward integration of geospatial capabilities into the world's
information systems.
Lance McKee
Vice President,
Corporate Communications and Public Sector Programs
Open GIS Consortium, Inc.
35 Main Street
Wayland, MA 01778 USA
Tel. 508-655-5858
Fax 508-655-2237
http://www.opengis.org
lmckee at opengis.org
www.opengis.org
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