Comparison of AIRGrav and GT-1A airborne gravimeters for research applications

Airborne gravimetry has played a vital role in contributing to our knowledge of the subglacial environment in polar regions. Previous programs have produced extensive gravity data sets in Antarctica, but the resolution and accuracy of the data have been limited. We have evaluated the relative performance and suitability of two different airborne gravimeters for research applications from flight tests over the Canadian Rocky Mountains near Calgary. Survey design, mission profiles, and demands on the performance of an airborne gravimeter are different for the remote polar environment than for most commercial exploration surveys. Both systems, the AIRGrav and GT-1A, can produce higher-resolution data with improved flight efficiency than can the BGM-3 and LaCoste & Romberg gravimeters used in Antarctica. The AIRGrav and GT-1A systems are capable of draped flying of airborne gravity, allowing new applications for polar use. Both systems could provide the academic community with a significant increase in accuracy and horizontal resolution to enable major advances in understanding the subglacial environment. Compared to the GT-1A system, the AIRGrav system has a lower noise level and higher accuracy, and it is less sensitive to changing flight conditions - in particular, vertical accelerations during turbulent flights.