Bushtrail subsurface mapping using flexible GPR Antenna tracked by mini-GPS loggers

Abstract

Rough Terrain GPR Antennae made of flexible hose are dragged along small trails to image near surface geology in field areas with dense vegetation and rugged topography. For accurate antenna midpoint coordinates between transmitter and receiver two miniature GPS receivers are attached to such a snake-like 50 MHz GPR antenna. During a three day field test on a Pleistocene highstand reef complex in the Dominican Republic 21 km of 2D GPR profiles were acquired. Differential post-processing of the raw GPS data recorded by the two GPS rovers attached to the GPR antenna together with a third stationary GPS receiver yields sub-meter precise GPR profile coordinates on gravel roads and trails. The reef carbonates are imaged to depths of 15 m along bushtrails. Data quality is degraded on gravel roads due to conductive road fill material. Overall, the network of 2D GPR profiles provides an accurate framework of the near surface geology for 3D visualization and facies correlation.