Rapid processing of GPR time slices for data visualisation during field acquisition

Recent developments in multi-channel instrumentation now allow unprecedented levels of high sample density GPR to be collected over very large areas. The volume of data created by such surveys can present a significant challenge for data processing and it is often only undertaken after the field work has been completed. This paper describes the development of software tools to allow the rapid processing of continuous wave stepped frequency GPR data in the field, with each swath of mutli-channel measurements processed immediately following completion of the line whilst the system continues data acquisition. The data are processed to a full series of geo-referenced amplitude time slices allowing in-field quality assurance of both the GPR signal and positioning information (e.g. GPS coordinates). This immediate analysis also allows both the density of survey coverage to be confirmed, so that large gaps between instrument swaths can be avoided, and the extent of the survey to be adjusted in relation to the detected anomalies. The instant display of processed results has also proved useful when demonstrating the GPR technique to surveyors who have not used this technique before.