Location, Location, Location
When the City of Chattanooga mapping project in Tennessee went out for proposals in 2007, Dixie Brackett of Earthworx Inc. knew she and her firm would be up against many large consultants trying to win the project. She also knew she was venturing into territory that most land survey companies were unfamiliar with: mapping projects with deliverables in Esri.
Nevertheless, she had a few advantages that set her apart. She owned copies of Esri ArcView and ArcMap; she owned Carlson SurvCE, a field product with full GIS capabilities that could output Esri shapefiles; and she had staff familiar with these products and how to link the data from the field into Esri. Brackett submitted her bid for the storm sewer mapping project and won. And then she did something even more unusual--she delivered the project ahead of schedule and with accuracies that exceeded specifications. This project promptly set Earthworx on a course of growth driven largely by GIS-related mapping. Earthworx grew by 32 percent in the recession year of 2009 and won the Esri Special Achievement in GIS (SAG) Award in 2010.
Since the origins of GIS, land surveyors and GIS professionals have been separated by a gaping chasm that still remains. GIS professionals often pull back when they hear the term “survey,” and too few professional land surveyors have familiarized themselves with the concept of line and point attributes and mapping in Esri, the common platform for GIS.
In recent years, Esri has begun to promote other methods besides shapefiles for file linkage. One method embeds all Esri drawing elements and associated attribute data in a .dwg file that Esri will export (through an “Export to CAD” option, available in ArcMap 9.3.1 or later). Field products such as SurvCE and SurvPC, Carlson’s data collection program for PCs, can now read the Esri-defined MCS data format in the .dwg file and extract all GIS prompting automatically. Then, after field data collection is completed, the drawing can be exported and read back into the Esri map with all the new attributing included. This process also uses a conventional .dwg file as the link, as opposed to a shapefile.
All these methods of linking to Esri have evolved since Earthworx engaged in the Chattanooga storm sewer mapping project in 2008. The resulting information is proving increasingly valuable to utilities and communities.
In the absence of good mapping, the primary method for locating buried utilities of all types is the use of utility locators. By using locators in conjunction with SurvGIS, a simplified GIS program that includes links to a variety of cable and utility detectors, a point can be stored when the utility is detected. With multiple points, portions of the utility lines can be drawn using field coding. This process is useful for mapping and for utility location prior to construction or repair.
The field techniques for GIS mapping are evolving quickly. Companies like Earthworx are the early pioneers in accurate GIS mapping. Now, with techniques like augmented reality and photo-linked attributing, land survey firms can provide even more valuable services to the GIS industry and tap new sources of growth.
*At press time, SurvGIS was still under development with the release date to be determined.