Geographic Information Systems

The primary responsibility of the DSET GIS Team is to update and maintain the GIS spatial mapping data used for locating and routing Connecticut’s 9-1-1 calls.

Other responsibilities include map production and GIS support for the rest of DESPP.


9-1-1 GIS Metrics

Street Centerline Updating – DSET continues to collect and process street and address updates that have been provided by the towns and PSAPs. DSET has updated/verified a total of 78,123 street segments since taking over the updating process from Tele Atlas. Please contact Dan Czaja, GIS Coordinator, at (860) 685-8131 or to submit a correction or for further information.

Address Points added to Next Generation 9-1-1 (NG 9-1-1) systemDSET has added GIS building and tax parcel center address points for many of Connecticut’s municipalities to the NG 9-1-1 system. This GIS dataset is used in conjunction with the GIS street centerline to further improve call location accuracy.

Legacy 9-1-1 ALI Geocoding Results – DSET continues to improve the geocoding match rate of the ALI database using the street centerline.  As of April 1, 2019, the geocoding match rate has reached 99.14% of all ALI records geocoded.

Next Generation 9-1-1 ALI Geocoding Results With the addition of address points, DSET is able to improve the geocoding match rate for the ALI database in the NG 9-1-1 system.  As of April 1, 2019, the geocoding match rate has reached 99.42% of all ALI records geocoded.


9-1-1 Master Street Address Guide Updating

DSET GIS continues to provide updates and research support for the Master Street Address Guide (MSAG) used in the 9-1-1 system. To date, DSET has provided approximately 1,800 MSAG update requests to AT&T and now Frontier Communications since 2010.


2019 Statewide Orthoimagery Flight

The Department of Emergency Services and Public Protection (DESPP) has signed a memorandum of understanding with the Office of Policy and Management (OPM) to procure a statewide high-resolution aerial orthoimagery dataset. The orthoimagery will be leaf-off, six inch resolution, 4-bands (true color and near infrared), and will cover all of Connecticut (approximately 5,266 square miles). The orthoimagery is being procured through the United State Geological Survey (USGS) imagery acquisition program and jointly funded by DESPP, the Connecticut Department of Transportation (DOT), and the Connecticut Department of Energy and Environmental Protection (DEEP).  The orthoimagery will be publicly available without license restrictions, and will support the various missions of State, Regional, and Municipal government, including statewide 9-1-1.  As of July 1, 2019, the flight imagery acquisition period is complete and is currently in the QA/QC process with the vendor.  Data delivery to the State is slated for winter 2019-2020.


Agency GIS and Mapping Support

DSET GIS continues to assist other agency divisions with GIS and mapping support.  Examples include DSET GIS providing the Connecticut State Police (CSP) with a customized version of the 9-1-1 street centerline GIS dataset for their Computer Aided Dispatch and assisting the Crimes Analysis unit with analysis and mapping.


GIS Support for CTAlert ENS

DSET GIS continues to work with the state's emergency notification system vendor, Everbridge, to support the GIS portion of CTAlert ENS, including the maintenance of the mapped ALI database on a monthly basis and their new Resident Connection dataset.