Due to the sparse data coverage with surveying along contour lines and the lack of GPS positioning, both the spatial resolution and the spatial accuracy is low. In addition, some of the data (1975/76 surveys) were originally stored on magnetic tapes, which were partly under bad physical conditions.

The company DRTS Ltd, St Pauls Cray, Kent, England, a private company specialized in the recovery of data from old tapes, was contracted from GEUS to transfer the data from the tapes and most - but not all - of the data were recovered. Details about the data recovery process and data quality evaluation of the 1975/76 are given in the GEUS report 2003-37 “Digital airborne radiometric data from the 1975 and 1976” and we recommend to contact Thorkild Maack Rasmussen (now Luleå University, formerly GEUS), who was involved in this process, for any further information about this process.

Only counts for four windows were collected (probably total count, K, eU, eTh) and spectral data are missing. This very much limits the options of reprocessing and more advanced processing techniques for noise removal and radon reduction in the uranium window are not possible.

The gamma-spectrometer had been calibrated at a pad facility at Risø, which enabled the conversion of recorded counts per second in the four channels to simulated concentrations of radioactive components in the surface of the overflown terrain and K is given in % and eU and eTh in ppm.

In summary, the datasets are not comparable with nowadays acquired radiometric airborne data, neither in their data quality nor in the uniformity and density of the data coverage. This means the main value of these data lie in the regional extent such that large areas of West Greenland and South Greenland can be qualitatively evaluated in terms of the natural radioactive isotopes.