In the 1960’s Rex Morey, an engineer at Edgerton, Germeshausen and Grier, Inc (EG&G), was exploring with electromagnetic pulses (EMP) and verified that EMP could penetrate earth, rock and water.

Morey and another former engineer from EG&G, Art Drake, continued to investigate the technology and founded Geophysical Survey Systems, Inc in 1970. During their initial stages, the company worked on designing an electromagnetic subsurface profiling (ESP) system to be used by GSSI engineers and geophysicists to conduct geophysical surveys. ESP was a radar technique which accurately located geological and subsurface features before boring or excavating down to depths of 20 feet. The ESP method was a new method for anyone who needed to know what was under the ground.

In 1970, Morey and Drake designed the first commercial GPR system that was used for service work within the USA. This system consisted of three rack-mounted bays of equipment installed in a van. The two pictures below show this GPR system.

Fun Fact: GSSI’s first marketing brochure was designed in 1971 and the tag line was “Seeing underground. Without going underground.”

In 1973, GSSI decided to change the company direction from being a service provider to focus on the development, manufacture and sale of ground penetrating radar instruments for a variety of applications. Also, at this time, GSSI renamed the “ESP” system to “SIR” system, Subsurface Interface Radar. This more clearly described the equipment as a true RADAR system used to detect interfaces (property changes) in the subsurface of dielectric materials. The first patent for GPR, “Geophysical surveying system employing electromagnetic impulses,” was filed by Morey on behalf of GSSI in January 1972 and was awarded on April 23, 1974.

In 1973, GSSI introduced the SIR 8, a revolutionary top of the line system with a scientific processor with an added micro-computer for real-time signal enhancement. Between 1973-1975, GSSI developed specialized systems for various applications and sold the first portable GPR instrument in 1974. Picture below is the SIR 8 in use at the Giza Plateau in front of Khufu Pyramid.

In 1982, a growing GSSI had 15 employees and released the SIR 4R system. This system was created specifically for the nuclear power plant industry to find rebar in plants under construction. Below you will see the brochure for the SIR 4R. This system came with an antenna (transducer), control unit and a recorder to display the data collected. Compared to today’s concrete inspection systems, the SIR 4 was very large and heavy, weighing a total of 75 lbs. (34 kg).

In 1985, the SIR 3 was introduced and replaced the SIR 4 and 5, which were systems developed in the SIR 8 series. The SIR 3 was a breakthrough for GSSI because it was compact, field portable and easier to operate than any other available systems. Different versions of the SIR 3 were available for rebar locating, ice profiling and general subsurface investigations. The picture below is the SIR 3 system that was for general subsurface investigations.

GSSI’s Early Years and Innovation Timeline (1970-1989)

• 1973
  • SIR 7: all analog system with a modified Hewlett-Packard reel-to-reel tape recorder and a purchased EPC graphic recorder
  • SIR 6: Simplified operation for non-technical operators
  • SIR 5: configured specifically for ice
  • SIR 4: modified SIR 7 without tape recorder capability
• 1975: 900 MHz antenna originally designed for use in coal mines (Model 101/3101)
• 1977: GSSI headquarters moved from Billerica, MA to Hudson, NH
• 1979:
  • 400 MHz, high resolution, bi-static antenna (Model 3103)
  • 500 MHz, general purpose utility detector antenna (Model 3102)
• 1982: 1000 MHz antenna for rebar locating at nuclear plants (Model 3100)
• 1988:
  • Model 775 & 776 Transmitter: high-powered transmitters for 80-120 MHz antennas
  • Model 777 & 778 Transmitter: high-powered transmitters for 250-300 MHz antennas
  • 250 MHz shielded antenna (Model 3107 & 3207 Transducer)
  • F-20 Measuring Wheel with digital readout screen
  • 300 MHz antenna pair, mono and bi-static operation (Model 3205 Transducer)
  • 100 MHz, deep probing mono and bi-static antenna (Model 3207)
  • Model 38 VDU: real-time color video display. Small adapter box attached to PR-8300 or any other GSSI radar control unit via custom installed connectors. This adapter box converts the data output to a form capable of being displayed on a standard U.S. color television or N.T.S.C. color monitor.
• 1989: RADAN, first post-processing software package was released