The GT-1A airborne gravimeter brings proven design and fully automatic operation to mobile scalar gravity measurement. Intelligent Platform Control combined with continuously recorded wide dynamic range allows the collection of high quality data through periods of turbulence. Proprietary software provides on-side delta-g values for post-flight evaluation.
The wide dynamic range provides high precision data in calm to turbulent flying conditions; data is acquired through short periods of saturation in extreme turbulence by the automatic application of a reduced-order Kalman filter, enabling platform misalignment to be computed and hence controlled; the automatic calibration program computes accelerometer scale factors and errors in perpendicularity between the accelerometer sensitive axis and the platform surface. The GT-1A installation in a fixed wing aircraft is shown in Fig 1 (courtesy of Airborne Petroleum Geophysics Ltd)
The GT-1A is hermetically sealed for protection when operating in environmental extremes. Short lead-ins improve survey efficiency and reduce costs. Filters depending on aircraft speed and flight conditions provide spatial resolution typically ranging from 1.2 kms to 3.5 kms.
|9.75 to 9.85
|Drift per day (corrected)
|+10 to +50
|150 at 27Vdc
|Weight (without rotation table)
|Dimensions (without rotation table)
|400 x 400 x 600 h
|Standard deviation in gravity anomaly estimation
|Under the following conditions
|maximum vertical acceleration GT-1A
|constant barometric altitude
|dual frequency GPS receivers of at least
|minimum number of visible satellites