How the OpenGIS
Specification Will
Impact Surveying and Mapping
An Open GIS Consortium (OGC)
White Paper
Lance McKee
Vice President, Corporate Communications
lmckee@opengis.org
and
Cliff Kottman, Ph.D.
Vice President, Technology Development
ckottman@opengis.org
Digital data is
convertible, copyable, storable, analyzable, mixable, visualizable and
transmittable beyond our imaginations. Generating digital survey records from
total stations was a baby step. Digitizing paper maps was a baby step. Such
data products and the people who painstakingly created them will soon be thrust
headlong into a much larger world characterized by the following four technical
and market advances:
1. By the year 2000
there will be more than twenty commercial Earth imaging and remote sensing
satellite companies, and many more distributors and value-added suppliers.
Similar sensor systems on airborne platforms can provide more time-specific coverage
and better resolution, in three dimensions. Sophisticated software tools are
being used to enable digital images to be accurately and automatically
orthorectified, adjusted so that the image coordinates of a feature map
directly to the Earth coordinates of that feature. This increases the value of
the images because they can be used in more situations with other kinds of
geodata, including vector-based digital maps. Other software advances are
making it easier to automatically extract features and create thematic maps,
such as maps of railroad tracks, topographical maps, or temperature
distribution maps. The precision of remote sensing is not equal to that of
conventional surveying techniques, but it is improving, and it is already
sufficient, and superior in cost and product, for many uses.
2. GPS units are
shrinking in size and cost. They are available now in laptop computers and will
within a few years be available in cell phones and other small personal
communications and computing devices. Many commercial vehicles now use GPS as a
primary navigation device. The precision of GPS is not equal to that of
conventional surveying techniques, but it is improving, and it is already
sufficient, and superior in cost and service, for many uses.
3. General purpose
database software products from companies like Oracle, Microsoft, IBM, and
Informix are being enhanced so that they efficiently store geographic
information. Previously, spatial databases were special purpose systems, each
proprietarily linked to a particular GIS. Now, complex geospatial information
can be stored with other kinds of information. Likewise, information of any
kind that is linked to spatially distributed phenomena can be spatially
analyzed, shared with other systems that manage spatial information, and
graphed and displayed as maps of various kinds. All of these companies are
refining their database products for serving data and services to Web users.
4. The geospatial
technical and market advances listed above are happening in parallel with a
revolution in data communications and distributed computing. Mobile computers,
embedded in vehicle control panels (and before long in "information
appliances" such as binoculars, pilot’s goggles, cameras, and compass
units), will know where they are and connect wirelessly to the Internet and
thus have access to and contribute to geodata and geoprocessing software
resources on servers around the world.
Interoperability
among network-resident geodata and geoprocessing resources is a key requirement
if geographic information is to benefit from advances 3 and 4. *Geodata*
interoperability depends on geodata-producing organizations learning to
coordinate on data content standards and metadata standards. That is not the
business of the OpenGIS Consortium, Inc. (OGC), except that OGC will provide
standard ways for software to manage metadata, semantics, etc. OGC’s business
is *geoprocessing* interoperability, that is, helping geoprocessing software
vendors reach consensus on software interfaces that enable their systems to
communicate with each other. OGC brings together representatives from about 150
key geoprocessing technology providers, technology users (federal agencies and
telcos, for example), geodata providers, and academics in bimonthly Technical
Committee and Management Committee meetings. The work being done in OGC will
enable the full integration of geospatial data and geoprocessing resources into
mainstream computing and the widespread use of interoperable, commercial
geoprocessing software throughout the global information infrastructure.
By specifying open
interfaces which comprise a single geoprocessing "lingua franca,"
OGC’s OpenGIS Specification largely eliminates the need for data exchange
format standards and costly batch data conversion. The open interface approach
enables geoprocessing to become an integral part of the new distributed
computing paradigm in which applets, middleware, components, e-commerce tools,
and object request brokers give any networked computing device real-time access
to a huge universe of data and processing resources. Where is the 411 directory
service provider? You don’t care. Likewise, data source, coordinate
transformation, conflation, proximity analysis, etc. will happen, but the user
who wants a bit of geographic information won’t care where or how.
Where does that
leave the surveyor and mapmaker? Old money-making tasks will fall away and new
ones will arise. It’s an unstable situation which will reward those who can
help their clients by combining an understanding of property records and laws,
dig-safe, civil engineering, planning, environmental management, farming,
forestry, etc. with a practical understanding of emerging geoinformation
products, services, and technologies.