Airborne geophysical surveys applied to urban/brownfield investigations

A number of airborne geophysical surveys have now been conducted in the UK using a fixed- wing system operated jointly by the British and Finnish Geological Surveys. The system provides magnetic, radiometric and frequency domain electromagnetic survey measurements. Regulatory survey permissions force a variety of flight elevations typically between 54 to 244 m. On the fringes of major conurbations, we encounter urban greenspace and brownfield areas. These areas may contain mixtures of infrastructure and built structures together with derelict and green areas. In order to provide valid interpretations of the airborne data, detailed studies of the behaviour of the data to a variety of influences found in the urban fringe of a town have been made. Non-geophysical spatial data sets are increasingly being applied to aid both the processing and interpretation of the survey data. This is particularly true in non-rural areas. Examples from a high-resolution survey acquired across a 5 x 5 km coastal area to the west of Irvine, Scotland are considered.