In 2005 the Center for Urban Research partnered with the NYC Department of Finance to help the Department evaluate handheld devices enhanced with geographic information system (GIS) maps to improve data collection for property valuation and tax assessment purposes.
The project developed out of a meeting in fall 2005 between CUR and the Department's leadership to discuss how CUR could help DOF analyze changing neighborhood characteristics based on assessment data, especially related to the increases in new construction in the city. We would use CUR's GIS expertise plus our experiences with parcel-based information delivery systems such as OASIS NYC (including the use of handheld devices to collect local data).
At the time, the NYS Office of Real Property Services (ORPS) had published a request for proposals for a grant program designed to improve the efficiency and effectiveness of business processes through intergovernmental collaboration and cooperation in the use of real property data. We realized the grant could provide an opportunity to develop a pilot project using handheld, GIS-based computers to collect data on new construction sites. This would help DOF begin to use more efficient technologies for its assessment work, and also obtain more current information about these properties. This would also help researchers and other public agencies obtain quicker access to this information.
The Department submitted a proposal in December 2005 to the ORPS Real Property Tax Administration Technology Improvement Grant Program (RPTATIP). The proposal outlined a pilot project with the overall goals of developing a proof-of-concept application; improving data efficiencies; and facilitating research on changing neighborhood characteristics with access to better & more timely property data.
The actual handheld device would include a customized GIS application that assessors could use as a map-based data entry system. The focus would be on new construction properties in order to have a limited universe but also one with real-world implications.
Once the project was completed, DOF would evaluate it to determine whether to expand it throughout the Department, and also to make it available to other assessment agencies throughout New York State for evaluation and further customization.
How the Center for Urban Research helped
The Center worked closely with Department staff to understand the workflow for assessing properties and using DOF's Computer Assisted Mass Appraisal (CAMA) system. We also evaluated state-of-the-art handheld devices to see which ones best matched the requirements of this project and the needs of DOF's assessment staff. The Department selected the CN3 device from Intermec for the pilot project, primarily due to its "rugged" design (see photo).
We integrated ESRI's latest ArcGIS Server software components into the project to provide DOF with a lightweight but powerful set of mapping tools for the selected handheld device. We used our GIS to analyze wireless potential in the city. Finally, CUR's web servers running ArcGIS Server are storing data collected during the pilot project, ready to be integrated into CAMA.
As the project got underway, CUR hired a consultant to develop the actual handheld software that would interact with the Department's CAMA system, as well as to advise the project team on the changing mobile computer industry. The consultant -- Michael Uffer of 408 Group based in Brooklyn -- had extensive experience designing mobile data collection applications for the US Census Bureau, New York City Department of City Planning and others. Michael worked closely with the project team members to develop an elegant application that met the major goals of the grant proposal. His work was crucial in making the project a success.
Our specific activities related to integrating ESRI's GIS tools into the project involved creating a system to display parcel-based maps in GIS format at multiple geographic scales in order to integrate mapping functionality into the handheld application. This involved:
- configuring ArcGIS Server 9.2 on CUR's servers (the grant application referenced ArcPad and ArcPad Application Builder, but the new 9.2 server software includes ESRI’s new ArcGIS Mobile development environment -- Mobile ADF Framework for .NET -- a lighter-weight and more customizable alternative to ArcPad);
- creating a series of borough-wide MXD files using ArcGIS Desktop 9.2 linked to a geodatabase of parcel boundaries, streets, and other reference layers, and then converting those files using ArcGIS Server into WMS web services to be accessed by the handheld device; and
- testing and modifying the MXDs to ensure the best display of the mapped information on the handheld screens.
GIS was also essential to help meet the challenge of wireless access for the pilot project. An important DOF criterion was that the handheld devices needed to access CAMA's mainframe system via a wireless connection so “live” CAMA data could be used by the assessor and new or updated data could be uploaded in real-time.
The first step in evaluating wireless connectivity options was to determine wireless coverage throughout the city. We obtained a database from the city’s Economic Development Corporation of “wi-fi” hotspots throughout the five boroughs, current as of November 2006. The list included 1,058 hotspots with mappable address locations. Roughly a third of these were characterized by EDC as free; the rest are fee-based.
The telecommunications industry standard for the typical outdoor range for wireless routers is approximately 300 feet. We used ArcGIS to calculate the area within a 300 foot buffer around all hotspots and totaled that area citywide in order to compare it to the city’s land mass. This analysis excluded large parks, airports, and major cemeteries in order to produce a denominator that accurately reflected the potential land area in which assessors would be working. This analysis determined that:
- The total wifi hotspot area is approximately 8 square miles;
- The total land area (minus the large parks, etc.) is approximately 272 square miles;
- Therefore, wifi hotspots only cover about 3% of the area in which assessors would be working; and
- Since only about a third of the hotspots are free, just 1% of the city is covered by free wifi access.
- The map at right highlights the limited area covered by wifi hotspots (all areas in white are outside the hotspot coverage).
These findings indicated strongly that the assessors would not be able to rely only on wireless connectivity to access CAMA and/or upload data to CAMA, at least on a real-time basis. As a result, the project team implemented several contingencies. For example, the handheld devices were configured so that they would be able to use a cellular network for Internet connectivity.
Pilot project success
The Department’s assessment team tested the handheld application in the field during Fall 2007. Overall they had positive feedback, especially on the ease-of-use of the device and the potential for this technology to increase productivity and enhance data quality. The Department is reviewing the findings and evaluating next steps such as deploying and/or further testing of the application by its field assessors.
For details of the project results, the final report is available from the NYS ORPS website.
For more information, contact:
NYC Department of Finance: Herb Stratton, Technology Solutions Group, firstname.lastname@example.org
CUNY Center for Urban Research: Steven Romalewski, email@example.com