Ground-truthing airborne geophysical data for carbon stock monitoring

This research project uses previously generated airborne Tellus radiometric data (Tellus project, GSNI) and newly acquired data collected as part of the EU-funded Tellus Border project to improve peat depth models for Northern Ireland and the bordering counties of the Republic of Ireland. The theory being tested is that gamma radiation from rocks is attenuated by overlying peat. Improved peat depth models produced though the integration and calibration of the Tellus data against known peat depths are used to improve carbon stock estimations. A 6km test line of the airborne survey is undertaken every 4-6 weeks and flown at a series of different elevations to allow the data to be assessed temporally with different saturation levels. An associated field survey takes place every 4-6 weeks to obtain data on the ground to correspond as closely as possible to the timing of the airborne flight survey. Analysis techniques on the ground include magnetometry, resistivity, radiometrics, moisture content, GPR and peat probing. Results for the airborne flight survey and ground-based data collection indicate that similarities between the traces can be identified. Ground validation enables the effect of changes in factors such as soil moisture to be assessed for the airborne radiometric data.