Initial appraisal of ground probing radar for site investigation in Britain : Darracott, B W; Lake, M I Ground Engng, V14, N3, April 1981, P14–18

Abstract

This article describes the equipment and the use of the method on a number of typical site investigations. The results of the tests are given and some of the problems and limitations of UK are discussed. The system used was that manufactured by Geophysical Survey Systems Inc (GSSI) of New Hampshire, USA, and is designed primarily as a shallow sub-surface exploration tool for engineering applications. The radiated signal is in the form of an electromagnetic 3 nano second transient in the low vhf range. Reflected waves can be displaced on a chart recorder calibrated in terms of depth. The resolution depends upon the pulse length and the frequency of the signals. Soil conductivity places the greatest limitations on the use of radar, but in favourable conditions penetration of up to 30 metres can be obtained. Results from the nine tests in various conditions described show that the technique appears to work well in sandy soils where ground water is fresh and in rocks. It is best used where known targets such as pipes, sewers or old foundations are being searched for. The system does not work at all well in areas where there are near-surface clays. (TRRL)