CAI Field GIS solutions for Public Works data collection
The PWIM® department of Cartographic Associates, Inc. (CAI) has been working with municipal Public Works departments throughout New England since 1996. Using leading GPS technologies and ESRI software, PWIM® has been creating GIS data sets that will allow for complete coverage of Public Works system information throughout a municipality. Our GIS data set includes the spatial locations of the Public Works features as well as a comprehensive database of attribute information (such as pipe diameter and material) to suit each client's needs.
Taking Public Works GIS data into the Field
Using the Global Positioning System (GPS) allows us to locate Public Works features, such as Fire Hydrants
or Manholes, with sub-meter accuracy. With GPS equipment and ESRI's ArcPad software built for hand-held computers, GIS data can be taken into the field; to view the data being collected while it is being collected and, of equal value, to be able to validate the location of existing features.
Having a complete data collection tool will ensure that all the required information is collected without spending extra time in the field. CAI works very closely with the Public Works staff to verify that every feature is located and to assist collecting all important attribute information. This attribute information can be entered during data collection to minimize the need for revisiting features, thus creating the most efficient and cost-effective data collection possible. Data collection is not limited to just GPS data; PWIM® integrates all available Public Works information for each project including As-Built Plans, Tie-Cards, Data Tables, and knowledge from the Public Works staff themselves.
Referencing Point Locations to other Points
For areas that contain a dense network of point features, such as complex intersections or where multiple pipes intersect, point features may be located within 3 feet of each other. To accommodate these situations, PWIM® has created tools for the ArcPad software that allow us to integrate GPS-located features with relative distances and bearings of those features close to the GPS positions. The result is an intelligent GIS system that properly represents the spatial relationship of these tightly-located features without the need for extra work, either in the field or in the office. This tool is often used even when features are more than 3 feet apart to maintain the proper spatial relationship between features in the GIS.
Creating Pipeline Connectivity
PWIM® also has tools for ArcPad that establishes connectivity between point features and the pipelines that connect them while collecting the GPS data in the field. The pipelines contain attribute information similar to the point features, and the PWIM® system also remembers this connectivity. If point features are ever updated or re-located, the pipelines can move with them. Pipeline connectivity is created using pipeline segments connected from one point feature to another. Pipeline curvature can thus be properly modeled as segment deflections as opposed to smooth curves, allowing for the most accurate representation of the Public Works systems.
Contact:
Tim Fountain
GIS Services
tfountain@cai-info.com
