Q. How deep can I penetrate with Subsurface Interface Radar?

A. Depth of penetration is dependent on the type of soil/media being investigated. The best penetration results are obtained in low conductive/highly resistive soils like dry sands. The poorest results occur in highly conductive soils like heavy, wet clays. We normally promote a maximum depth of penetration of 100 ft, with the optimum application zone between 0 to 30 ft. Some examples where maximum penetration was achieved:

1. When coupled directly to granite rock for fracture mapping depth of penetration exceeded 60 m (197 ft).
2. In the snow pack of Greenland surveyors identified buried aircraft 200 ft. deep.

GSSI has charts identifying approximate dielectric and conductivity values of various media. Using these numbers as a reference guide you can determine the expected depth of penetration for a site.

Q. What size targets can I detect with Subsurface Interface Radar?

A. This question usually pertains to the identification of man emplaced objects like underground utilities. Through years of field experiences GSSI has established a general "rule of thumb" for the detection of pipe like targets. You need one (1) foot of embedment. In other words, at five (5) feet deep you need a five inch diameter pipe. Like depth of penetration, the conductivity and dielectric properties of the media and target play a large role. The proper determination of resolution is that the target size must be equal to 1/2 the wavelength of the pulsed energy. A copy of the following paper can be obtained from GSSI and discusses how dielectric constants effect resolution and reflection strength of various targets.

Assessment of Ground Penetrating Radar Applicability to Specific Site Investigations:
Simple methods for pre-survey estimation of likely dielectric constants, target resolution & reflection strengths.

Technical Solutions

Frequently Asked Questions Technical Solutions provides questions and answers to many common questions asked by GSSI customers. This can be a valuable resource for solving technical issues without needing to contact GSSI. Of course, we are always happy to provide technical support to our customers, and all customers should feel free to contact us at any time if they have any questions concerning GSSI products.