GIS design reaps rewards
Garland, Texas, is one of the first cities in the nation to reap the rewards of the Tri-Service Spatial Data Standards (TSSDS) in the construction of its city-wide GIS. In just under four weeks, the city designed a flexible, manageable GIS design model based on these standards.
Today, developers are focused on building custom GIS-based applications designed to place mapping functions on the desktops of nearly every city department. TSSDS, designed and maintained by the Tri-Service CADD/GIS Technology Center at the U.S. Army Corps of Engineers’ Waterways Experiment Station in Vicksburg, Miss., was originally developed as a comprehensive master and environmental planning data model for military installations and civil works projects.
Currently, that standard supports a variety of applications including comprehensive master and environmental planning; architecture, engineering and construction; and automated mapping/facilities management. Based on the Spatial Data Transfer Standards, the software addresses data content, classification, format and presentation of geospatial entities depicted in large-scale mapping. In fact, the TSSDS defines some 2,000 features such as parcels, roads, water lines, storm sewers, telephone poles and culverts. The software ties the data in a file to the geographic entity that is on a map, thereby making the data accurate and allowing a city to design a system based on a standard that is broad in scale.
For example, a city can select the necessary requirements to fulfill current design needs. If these design requirements change or expand in the future, the developers have the entire TSSDS resource of pre-defined features to draw from. Garland used the TSSDS framework at GIS design inception to feature code the data entities. Developers were able to pull the required standard definitions–such as streets, utility features and buildings–from the software model as needed. The process took about four weeks, far less than original estimates. In fact, other cities without the benefit of the standards experienced delays of several years. In addition, TSSDS is designed for use on multiple CADD/GIS platforms and provides a standardized forum for sharing information, such as drawings, attributes or symbology, in GIS/CAD environments. This meant the city could select from GIS solutions based on functionality and not compatibility. Garland’s goal is to implement GIS mapping and analysis functionality throughout all city departments. Orthophotographic data to support this system is available through the North Texas GIS Consortium, which provides one-meter precision orthophotogrammetry of the Dallas/Fort Worth metroplex and surrounding suburbs to member agencies.
This data is updated annually and includes aerial photographs as well as street curblines, street centerlines, railroads, hydrography and digital elevation models. A potential application might be as simple as providing citizens with current maps of the city parks or as extensive as preparing a five year environmental planning program.
