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Facilities Survey Feasible With GIS and GPS
By Mohamed El-Gafy, and Yassir AbdelRazig, Florida State University

The analysis of existing facilities at the Florida A&M University (FAMU)Florida State University (FSU) campus in Tallahassee, Florida, is part of an overall campus planning initiative. The FSU campus plan addresses broad campus and environmental issues within the framework of the university mission and identifies specific facility improvements necessary to support existing and future programs. The existing facilities survey did not help management because it did not supply sufficiently current information on the condition and use of emergency phones and other campus facilities.

This article describes a data collection project that used GPS to furnish the current and correct data necessary to evaluate changes in allocation and configuration of facilities in the campus plan. This class project involved collecting data for emergency phones, fire hydrants, and manhole covers on campus utilizing the available resources at the university laboratories. This data was used to update the university database and will be integrated into a database that will serve as the foundation for a GIS system for university facilities.

The only qualitative criteria guiding the project were that the mapping software should be simple to use and would provide a starting point for GIS development and that GPS receivers would supply data of submeter accuracy or better. These criteria would allow for the development of facility maps sufficiently accurate for planning and management purposes, but not for use in design drawings.

The solution developed used three Trimble receivers, or rovers, to collect necessary field data in addition to a PC-based computer. This data would be associated with legacy data using ArcInfo.

Premission planning included accessing satellite positions prior to the fieldwork phase to ensure that the satellite geometry and availability would be acceptable and provide sufficient positional accuracy. The data required for this process was obtained from the Trimble Web site.

The team consisted of one graduate student and two senior undergraduate students. Training the team in the use of GPS receivers was simple. The original plan called for teaming each undergraduate student with the graduate student and supplying follow-up training as needed. However, after collecting data for three or four points, the students were comfortable using the system and needed no further training.

With the help of the university facility managers, the team determined what attribute data would be collected. See Table 1 (below) for a listing of attributes collected for each type of feature. Once the fieldwork was completed, files from the receivers were transferred to the university computer using Trimble GPS Pathfinder Office software. Because field data was not collected using a real-time radio link, it was accurate only to approximately 100 meters. [For an explanation of differential correction of GPS data, see "Differential GPS Explained" in the January–March 2003 issue of ArcUser.] All positional corrections were made in postprocessing mode using Pathfinder Office. The software compares the satellite constellation used by the roving receiver for computing a position with the raw measurement data in the base file from each satellite in the constellation. Base file data was collected at known locations at the same time that field data was collected. Once the positional files were corrected, they were converted to a format suitable for export.

The data, in World Geodetic System 1984 (the default datum for GPS receivers), was added to a map created in ArcInfo and the files were reprojected into Florida State Plane FIPS 903. The university-legacy database files were converted to dBASE (DBF) file format and joined with the collected GPS data.

Layers containing the university-streets were added to the map. Satellite imagery of the campus was used to digitize the university building footprints and provide a background layer for the map. Adding these layers supplied context for the features that were collected and helped determine if they were optimally located. New features were added, bogus features removed, and most retained features were shifted slightly to more correct locations.

The facilities survey is now a management tool that provides use, condition, and budgeting documentation that will be used for facility planning and addressing deferred maintenance. For more information, contact

Mohamed El-Gafy, Doctoral Student
Tel.: 850-410-6581
Fax: 850-410-6142
E-mail: mgafy@eng.fsu.edu
or
Yassir AbdelRazig, Assistant Professor
Tel.: 850-410-6453
Fax: 850-410-6142
E-mail: abdelraz@eng.fsu.edu

Department of Civil and Environmental Engineering
FAMUFSU
College of Engineering, Room B 310
2525 Pottsdamer Street
Tallahassee, Florida 32301-6046

About the Authors

Mohamed El-Gafy is a doctoral student in the Department of Civil and Environmental Engineering at Florida State University and is pursuing a research project that utilizes remote sensing and GIS technologies in civil infrastructure management and has completed course work in GIS.

Dr. AbdelRazig is an assistant professor in the Department of Civil and Environmental Engineering at Florida A&M University Florida State University. His research interests include GIS applications in civil engineering. He has a $100,000 grant to investigate the applications of technologies, such as GIS for infrastructure management, and has presented his research at many conferences.

References

Wells, D.E., N. Deck, D. Delikaraoglou, A. Keleusberg, E.J. Karakiwsky, G. Lachapelle, R.B. Langeley, S.M. Nakiboglou, K.P. Schwarz, J.M. Tranquilla, and P. Vanicek, Guide to GPS Positioning, Canadian GPS Asssociates, Fredericton, New Brunswick, Canada, 1986.

Mertikeas, S., Study of the NAVSTAR/GPS for Hydrographic Surveys and Sea Navigation, Part 1, 1989. Trimble, GPS Pathfinder Office: Getting Started, version 2.80, 2001.

Fire hydrants Year of manufacture (cast in the side of the hydrant base), make, general condition, the name of the street the hydrant faced, verification that the blue reflector was correctly placed in the street, and hydrant location
Emergency phones The number on the phone (used as a unique identifier), color, appearance, functional status, and general condition
Manhole covers Serial number, year of manufacture, make, general condition, the name of the street where the manhole was located
Table 1: Attributes collected for facilities
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