The Ground Penetrating Radar (GPR) system from Geophysical Survey Systems, Inc. is operated by a trained member of the INSTAP Publication Team (currently during summer months). Data is collected in individual transects, or profiles, along an x-y axis and depth is recorded in time (nS), which can be converted to meters. After data collection, the files are transferred to a computer and processed.
The equipment consists of an SIR-2000 (Subsurface Interface Radar) 400MHz antenna, an attachable survey wheel, two connector cables (1.83m and 30m), a harness, a transfer cable, two 12V batteries with a recharger, battery and car-lighter power adapters, an instructional video, and RADAN processing software with its security key on a laptop. Because the radar signal does not show exactly what an underground feature looks like, processing is necessary to clean the scans of any extra “noise” and false points. Once the profiles are processed, RADAN then connects each individual profile and creates a 3-dimensional cube of the survey grid. Elevation from an EDM can also be added during processing to adjust the scans according to the topography and give correct depth readings.
GPR is ideal for archaeological applications because it is a non-intrusive, and therefore nondestructive, method of survey enabling the archaeologist to see what is below the surface before any trenches are sunk. By detecting the location of features within a grid, the archaeologist is more aware of where promising features are located and can excavate that particular area.
For more information, contact Antonia Stamos, GPR Specialist