Ground Penetrating Radar (GPR) Survey
This is an example of data collected using ground penetrating radar. Ground penetrating radar creates an image file which shows cross sectional views of the subsurface features. The X axis in these images represents the distance of the features from a starting point. The Y axis shows relative depth. These relative depths can be converted to absolute depths when the depth of one or more of the utilities is known.
The following two images are two parallel cross-sectional views of a project site, taken 100 feet apart. These show what appears to be a total of four subsurface utilities. These images are 2 of a series of 20 parallel images taken for the purposes of mapping areas of concern for the existence of buried utilities. Utilities tend to show up on GPR images as parabolic shapes with sharp contrast between black and white. The probable utilities, labeled below, are supported by the fact that they appear in all images, in relatively the same locations. Furthermore, they have similar characteristics in size, shape and relative depth.
Cross-sectional view along station 0+00
Cross-sectional view along station 1+00
From here, these probable locations of utilities were mapped and shown in relation to the boundary of the parcel we were surveying. This data was then passed on to an engineer who made the decision as to which areas were critical and needed to be excavated for further study.
