Appendix B
Conclusions from the Workshop on Airborne Geophysics
The Workshop on Airborne Geophysics was held to assess the promise of airborne geophysical techniques and precise positioning in supporting future scientific research in regional geodesy, from surveying applications to the measurement of global warming indicators, such as glacier and ice sheet mass balance. The workshop addressed the following themes:
- GPS positioning;
- integrating GPS and Inertial Navigation Systems (INS);
- recovery of topography from aircraft;
- airborne gravity field measurements; and
- scientific objectives.
Following are the major conclusions of the workshop:
Workshop Conclusion 1: Current airborne geophysics technology is sufficiently mature to address basic research problems and commercial applications in both the resource and environmental fields. Increased visibility and access to the present systems would encourage wider application of airborne geophysics integrated with precise positioning.
Workshop Conclusion 2: Precise aircraft positioning capability with GPS should motivate development of techniques for swath mapping topography with an accuracy between 10 and 100 cm and the capability to detect changes in topography in the range of 1 to 10 cm. This would allow advances in profiling ice sheets, resolving the horizontal and vertical response of the Earth's surface following a major seismic event, detecting magma chamber swelling, and verifying nuclear test ban treaties.
Workshop Conclusion 3: Airborne gravity technology is currently capable of detecting anomalies with wavelengths of several kilometers and accuracies of several milligal. Increasing the accuracy and resolution of airborne gravity measurements to the sub-mGal and less than 1-km range should be pursued by enhancing precise positioning capabilities, improving
sensors, and developing new technologies such as gravity gradiometers. These high-resolution applications are of particular importance for mineral and petroleum resource evaluation.
Workshop Conclusion 4: Research and development in GPS and INS should more directly target high-accuracy aircraft applications. Much of the available hardware and software was designed specifically for static applications; airborne applications will require more attention on multipath problems, tracking loops, and reduction software.
Workshop Conclusion 5: The implementation of Antispoofing policies, which increase the difficulty in tracking the GPS signal, seriously encumbers future applications of airborne geophysics.