WorldWide Drilling Resource

10 NOVEMBER 2021 WorldWide Drilling Resource® Ground Penetrating Radar Technology Adapted from Information by Geophysical Survey Systems, Inc. (GSSI) Ground penetrating radar (GPR) is also known as georadar and ground probing radar. The GPR system has three main components: a control unit, an antenna, and a power supply. The control unit contains the electronics which trigger the pulse of radar energy the antenna sends into the ground. It also has a built-in computer and hard disk/solid state memory to store data for examination after fieldwork. Some systems, such as the GSSI SIR 30, are controlled by an attached laptop computer with preloaded control software. These allow data processing and interpretation without having to download radar files into another computer. The antenna receives the electrical pulse produced by the control unit, amplifies it, and transmits it into the ground or other medium at a particular frequency. Antenna frequency is an important consideration. The higher the antenna frequency, the shallower into the ground it penetrates, detecting only smaller targets. Depending upon the application and desired depth penetration, the user should consider the antenna frequency needed. GPR equipment can be run with a variety of power supplies, ranging from small rechargeable batteries to vehicle batteries and normal 110/220-volt. Connectors and adapters are available for each power source type. Working by sending a tiny pulse of energy into a material and recording the strength and time required for the return of any reflected signal, the GPR method collects a series of pulses over a single area, a scan. The data collected is then placed together in the appropriate locations for computer processing in a specialized software program such as GSSI’s RADAN. The computer produces a horizontal surface, a depth slice, at a particular depth in the record. In many situations, the GPR operator will simply note the location of a target so it can be avoided, necessitating only the use of a simple linescan format to mark the approximate area of the target on the survey surface. Other users may need more detailed subsurface maps and depth to features, requiring more complex GSSI GPR processing software. DIR 302-684-3197 FAX: 302-384-0643 142 Broadkill Rd. • Milton, DE 19968 email: Manufacturers of Slotted & Perforated Pipe ranging from ½” to 24” diameter Atlantic Screen & Mfg., Inc. • Well Rehab. Products • Manholes • Bentonite • Filter Sock • Inline Chemical Mixers • Sampling Bailers • Clear PVC Pipe • Locking Caps