Airborne gravity tests over Lake Ontario
| Autor: | John F. Halpenny, Dak M. Darbha |
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| Rok vydání: | 1995 |
| Předmět: | |
| Zdroj: | GEOPHYSICS. 60:61-65 |
| ISSN: | 1942-2156 0016-8033 |
| DOI: | 10.1190/1.1443763 |
| Popis: | Airborne gravity measurements were made over Lake Ontario in March 1991 to establish the feasibility of using a small survey aircraft for rapid and economical gravity surveys. A LaCoste & Romberg linear dynamic gravity meter, used with a PC lap‐top based digital controller, was operated in a twin‐engine Piper Navajo aircraft. A Trimble 4000 GPS receiver, operated in differential kinematic mode with a nearby base station, provided precise navigation, and radar and barometric altimeters provided additional altitude data. A major gravity low in eastern Lake Ontario, previously outlined by underwater gravity measurements, was surveyed with six lines from two flights at an altitude of 1000 ft (300 m). Large vertical accelerations caused by aircraft motion were almost completely removed using the height measurements, although separate reductions using global positioning system (GPS) and radar heights showed significant differences that indicated that the height measurements could still be improved. A grid formed of the differences between the smoothed air data and 56 underwater stations had a mean of −0.2 mGal and standard deviation of 2.7 mGal. |
| Databáze: | OpenAIRE |
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