Open AccessAirborne gravity and precise positioning for geologic applications
Author(s) -
Bell R. E.,
Childers V. A.,
Arko R. A.,
Blankenship D. D.,
Brozena J. M.
Publication year - 1999
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/1999jb900122
Subject(s) - geology , gravimetry , gravimeter , global positioning system , radar , geodesy , instrumentation (computer programming) , gravitational field , remote sensing , gravity anomaly , gradiometer , geophysics , altimeter , seismology , aerospace engineering , magnetometer , engineering , telecommunications , paleontology , casing , physics , geotechnical engineering , quantum mechanics , astronomy , oil field , computer science , magnetic field , reservoir modeling , operating system
Airborne gravimetry has become an important geophysical tool primarily because of advancements in methodology and instrumentation made in the past decade. Airborne gravity is especially useful when measured in conjunction with other geophysical data, such as magnetics, radar, and laser altimetry. The aerogeophysical survey over the West Antarctic ice sheet described in this paper is one such interdisciplinary study. This paper outlines in detail the instrumentation, survey and data processing methodology employed to perform airborne gravimetry from the multi‐instrumented Twin Otter aircraft. Precise positioning from carrier‐phase Global Positioning System (GPS) observations are combined with measurements of acceleration made by the gravity meter in the aircraft to obtain the free‐air gravity anomaly measurement at aircraft altitude. GPS data are processed using the Kinematic and Rapid Static (KARS) software program, and aircraft vertical acceleration and corrections for gravity data reduction are calculated from the GPS position solution. Accuracies for the free‐air anomaly are determined from crossover analysis after significant editing (2.98 mGal rms) and from a repeat track (1.39 mGal rms). The aerogeophysical survey covered a 300,000 km 2 region in West Antarctica over the course of five field seasons. The gravity data from the West Antarctic survey reveal the major geologic structures of the West Antarctic rift system, including the Whitmore Mountains, the Byrd Subglacial Basin, the Sinuous Ridge, the Ross Embayment, and Siple Dome. These measurements, in conjunction with magnetics and ice‐penetrating radar, provide the information required to reveal the tectonic fabric and history of this important region.