Data acquisition systems for ground penetrating radar with example applications from the air, the surface and boreholes

Abstract

Data acquisition for short-pulse (impulse) ground penetrating radar (GPR) has evolved as new technology has become available but commonly involves equivalent time sampling a radio-frequency signal to produce an audio-frequency replica of the signal. An airborne radar system developed by the U.S. Geological Survey (USGS) in 1978 recorded the sampled signal on analog tape. Low data rates made waveform addition (stacking) for signal-to-noise improvement impractical. Advances in data acquisition and recording that have occurred within the last two decades have made digital recording the norm in modern GPR's. Waveform addition for signal-tonoise enhancement is common. However, all commercial short-pulse GPR's known to the authors still use equivalent time sampling prior to digitizing. Fast single-shot digitizers are a viable alternative to equivalent time sampling in some applications.