Global Positioning System (GPS) Services

GPS’ Role in Environmental Site Assessment

A basic but essential component of quality site management is having an accurate spatial representation of where physical site features reside. Often times, older sites have survey and coordinate data which was acquired by previous contractors and consultants. This may be of suspect quality or even unknown coordinate systems and units. For the project manager of a new site, getting their arms around the site layout is the first step towards moving a site towards its specific goal. In either case, GPS technology offers a quality cost effective method for acquiring locational information. Acquiring site spatial information via GPS costs a fraction of the costs associated with a traditional survey.

Vast GPS Experience State-of-the Art Equipment

The staff at ddms has conducted GPS surveys at many large industrial sites all over the nation including international airports, bulk petroleum storage facilities, abandoned anthracite mines, landfills and brownfields to name but a few. We use survey-grade Trimble® GPS technology and can achieve a positional accuracy which fits the needs of the site. By default, ddms employs real-time Differential Global Positioning System (DGPS) technology to achieve 1.5 foot horizontal accuracy in the field. If site needs require it, we can achieve centimeter accuracy by using a combination of DGPS, Post Differential Correction and Carrier Phase data collection.

Once data has been processed and folded into the site GIS, it becomes an essential data set used to geo-reference CADs and site Aerial Photos. Analyst contouring environmental site data acquired from site wells and borings can do so with confidence that the integrity of the spatial locations used in their analysis is intact and not introducing any error in their physical environmental assessments.