A Pilot Project for Land base Migration
Dave Magee
Account Manager, Utilities
Jay Clark
Product Manager, Utilities
Bart Guetti
Software Engineer
Geographic Data Technology, Inc.
11 Lafayette St
Lebanon NH 03766
Telephone: 800 331-7881 ext. 1112
Fax: 603 653-0249
E-mail: jay_clark@gdt1.com
bart_guetti@gdt1.com
Abstratct
This presentation examines data modeling, topological maintenance, and alignment of multiple spatial data
sets in a project for Atlanta Gas Light Company. Processes include:
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conflation of public vector data with Geographic Data Technology’s addressed street centerline
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horizontal realignment of the resulting street network using aerial imagery
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auto-correlation of AGL’s street centerline to the improved landbase
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repositioning of AGL’s boundaries, point data, facilities and other data layers to the improved
geometry.
Introduction
This presentation discusses a pilot project undertaken by Geographic Data Technology, Inc. (GDT) for
Atlanta Gas Light Company (AGL), the eighth largest natural gas distribution utility in the United States.
Faced with advances in software and GIS technology since the development of their last GIS, AGL decided
that it was time both to replace their GIS software environment and to migrate to a more accurate and upto-
date landbase.
When GDT met with AGL in January 2001, discussions of the landbase migration process centered on
three key issues.
Data Quality
AGL wanted the new landbase to be spatially accurate enough to overlay an aerial image of equal or better
quality than a United States Geodetic Survey digital orthorectified quarter quadrangle (USGS DOQQ). This
would result in assumed horizontal accuracy of +/- 5 to 7 meters from “groundtruth”. AGL also stipulated
that attribution available with the data needed to be current and complete enough for service request and
Customer Information System (CIS) purposes.
Management of Facilities Data Conversion
AGL wanted to manage the alignment of their facility data to the new landbase in the most accurate and
efficient manner possible
Cost
AGL sought to balance the appropriate level of effort to get the job done correctly with a moderate budget.
AGL contracted a pilot project for DeKalb County, Georgia, in order to demonstrate the feasibility of a
solution from a commercial vendor such as GDT. DeKalb is one of the heavily urbanized counties that
make up the metropolitan Atlanta region.
The new Landbase Data
