Integration of Legacy, Cots, And Map Data
Gary S. Miller
Director - Project Implementation
Analytical Surveys, Inc., 741 N. Grand Avenue
Waukesha, WI 53186
M. Todd Rhodes
Project Implementation Analyst
Analytical Surveys, Inc., 741 N. Grand Avenue
Waukesha,WI53186
Introduction
The integration of legacy, commercially-available off-the-shelf (COTS) datasets and map data is
a key component of most of today's GIS implementation initiatives. In the past, GIS databases
were often constructed from a single map series. Today's GIS database construction
requirements typically include the integration of data from one or more legacy systems with one
or more map-type data systems. Additionally, the integration of COTS datasets has become an
accepted manner of enhancing GIS database content and fi.mctionality.
Geospatial system implementers are faced with the need to determine how and when legacy or
COTS data should be integrated with the map-born database. Thorough analysis and planning
can be the single most important determinant of success in accomplishing this integration.
This analysis and planning is especially important because there are numerous options with
regard to the manner in which the data integration is accomplished, and because the data
integration challenge should not be underestimated.
Evolution of Geospatial Systems
Historically, automated mapping, facilities management, and geographic information systems
addressed single, departmental requirements and applications. Yesterday's GISS used distinct
hardware and network configurations as well as GIS-specific programming languages. GIS
databases were usually separate from other databases within the enterprise.
Today's advanced geospatial systems use standard hardware configurations which are integrated
with enterprise-wide networks utilizing industry-standard programming languages. These
systems are designed and implemented to serve multi-departmental or enterprise-wide needs.
This new paradigm for geospatial systems both facilitates and requires the integration of large
diverse datasets into a single database or several databases that seamlessly interact with each
other.
Evolution of Geospatial Databases
Due to the limited functionality of yesterday's GIS systems, it was often appropriate to create a
geospatial database from a single map series. A more aggressive implementation might have
involved the integration of data from several map series'. While non-map datasets were
sometimes utilized as a supplemental source for the population of GIS attributes, even in such
cases, the previously separate databases were usually maintained separately even after portions
of the datasets had been integrated within the GIS. This situation limited the utilization
geospatial systems and the benefits of geospatial system implementation.
To derive maximum benefit from today's advanced geospatial systems, information from many
sources and datasets must be integrated within a single database or several searnlessly interfaced
databases.
Models for Integration
As previously stated, contemporary requirements for geospatial database content typically
include substantial data integration. Several models for achieving the required level of database
integration exist. The following subsections address these alternatives with regard to the
integration of legacy data and COTS data with map data.
Simultaneous Re~lacement of LeEacv Database and Map Data
It is possible, even common, for a single geospatial database to fully replace legacy and map
systems. It is also possible, though more challenging, to achieve that replacement in a
simultaneous manner. This model offers several advantages with regard to short-term and longterrn
database maintenance, and when feasible, maybe the most straightforward approach. In
many cases, however, the critical needs served by the legacy system may make this approach to
database construction inappropriate.
