Ground-Penetrating Radar is a remote sensing technique that is utilized in many environmental and civil engineering projects. In its basic form, Ground-Penetrating Radar equipment consists of a portable antenna and control unit. The Antenna is pulled along the ground surface over an area of interest and radar is transmitted into and reflected out of the ground based upon the conductivity of the subsurface materials encountered.
Several different antennas can be utilized depending upon the application and required depth of penetration. In typical Long Island sand, a 500 megahertz antenna can penetrate to depths ranging from 1 foot to 10 feet - the range most underground storage tanks and utilities are found within. A 300 megahertz antenna can penetrate depths of 15 feet or more and is suitable for surveying zones where debris piles, landfills or bedrock surfaces may be located. A small 1,000 megahertz antenna can locate re-bar or utility voids in concrete floors.
A Ground-Penetrating Radar survey can be utilized as a stand alone investigation or preliminary to a Phase II Environmental Site Assessment. In environmental applications, Ground-Penetrating Radar can verify the presence of suspected buried structures and delineate the boundaries of known underground storage tanks and drainage structures (ie. leachpools, cesspools or drywells). Previously excavated and backfilled areas such as former tank pits, landfills or other waste disposal locations can also be readily identified. In civil engineering applications, Ground-Penetrating Radar can identify the density of materials at various depths and locate the presence of voids beneath buildings or road surfaces. Ground-Penetrating Radar has even been used in archeological investigations to locate ancient Indian burial grounds.
In many instances, a conventional utility mark-out may not sufficiently clear a site of underground utilities or other buried obstructions for subsurface sampling to safely proceed. Or the floor of a building with utilities located beneath the concrete slab may need to be removed for renovation. In conjunction with utility locating detectors and magnetometers, Ground-Penetrating Radar can confirm the locations all underground utilities so you can be assured that the locations selected for coring or sampling will be clear of obstructions.
Once the Ground-Penetrating Radar and Utility Surveys are complete, the results can be spray painted on the ground surface so they can be utilized immediately. If a formal report is desired, the results can be transposed onto a diagram depicting the locations surveyed and all confirmed subsurface structures.
Ground-Penetrating Radar and Utility Surveys
