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STATEMENT OF THE PROBLEM
One goal of NASA’s research and application efforts is to
implement and operationalize the use of remotely sensed imagery
and technologies within the day-to-day business operations and management
of government. A major stumbling block to this integration is the
issue of the positional accuracy of the existing line-work within
the governments vector GIS database. This inaccuracy manifests itself
when overlain to more positional consistent imagery data as well
as when GPS data are used. This is a common problem with GIS, GPS,
and imagery that is occurring within governments across the nation.
NASA sponsored research has allowed the creation of tools and approaches
governments can use to co-register multiple layers of GIS information
to an imagery base and migrate their investment in GIS to better
positional accuracy.
SOCIAL BENEFITS
Local governments have made significant investments in GIS
data development (i.e. Springfield, MO - $15 million, 194 person
years, 175 data layers). Many of these investments were founded
on paper maps with little positional accuracy. When used as base
map resources, the resulting GIS layer is a database with many forms
of inherent positional error. This information does not map well
to the imagery products provided by NASA or the private sector.
Local governments are reluctant to use or show imagery if the imagery
displays significant errors in their data. The ability to ‘correct’
these errors in a systematic and repeatable process that enables
their investment in these data layers to be maintained into the
future is critical to NASA’s, or the private sector’s,
ability to integrate remote sensing products in these environments.
NASA`s UNIQUE CAPACITY AND CONTRIBUTION
A NASA funded process was developed that uses tie-points from imagery
sources to a GIS base map layer (i.e. parcels) to create a gridded
continuum of linearized adjustments. Once adjusted, the line work
is reassembled and topology reestablished. This tool has maintained
the integrity and the relative-positional accuracy of the vector
data. In addition, the tool documents the positional accuracy of
the new vector data layers.
DECISION
SUPPORT SOLUTIONS
Local governments have responsibilities mandated from the City,
County, Utilities and State Legislature. These mandates relate to
record keeping in many forms, map/drawing productions, maintenance,
economic development, and ultimately public safety.
NASA’s support of this application has provided future decision-makers,
and the public, with a much needed level of confidence in the information
they are using. The project allows county, city, and private sector
users to maximize the use of spatially integrated remote sensing
and GIS vector data.
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