Airborne Gravimetry is done with an advanced technology that seeks as far as Earth's gravitational field that extreme positioning accuracy and the plane attitude. The challenge is to subtract the measurement of the vertical acceleration due to gravity, all of a sudden acceleration by underwent by the plane or helicopter during the flight.
Sensors used for Airborne Gravimetry
GT-1A (or GT-2A) is a gravimetric GPS-INS scalar vertical sensor installed on a three-axis inertial platform, itself mounted on an anti-vibration support.
The main sensor weighs about 50 kg. Together, the sensor and inertial platform measure 40 x 40 x 70 cm. The anti-vibration support has a cutoff frequency of approximately 5 Hz and has a dimension of 60 cm in diameter by 22 cm high, giving the entire system a size of 92 cm.
System performance are described as follows:
Under the following conditions, the error in measuring the gravity anomaly is estimated at 0.6 mGal RMS using 100s filter (0.01 Hz cutoff frequency):
- Vertical acceleration of less than +/- 500 mGal 300 Hz;
- Optimum installation of the GPS antennas on the aircraft and on the ground;
- Using dual frequency GPS receivers;
- GPS Sampling Rate 2 Hz.
For more information, please contact our Airborne Survey Team