xcite xplorer xact xtract

With over 500,000 lkm’s of gravity survey completed, the system delivers by combining industry-leading Gravimetric Technology gravimeters mounted using NRG patented technology in a Pilatus PC6 aircraft renowned for its ability to fly slowly.


Fixed Wing Gravity and Magnetics

With over 500,000 Ikms of gravity survey completed, the Xtract™ system delivers by combining industry-leading GT gravimeters with an ideal slow-flying aircraft platform.

At the heart of the XTract™ system is a GT gravimeter system. Designed and built by Joint Stock Company Gravimetric Technologies in the Russian Federation, the system has been employed in both military and civilian applications including extensive use as an airborne gravimeter.

The gravity sensor is a custom-designed accelerometer mounted inside a gyro-stabilised unit. Inputs from the gyros, inclinometers, angle sensors and dual frequency GPS are used to drive servo motors which maintain the sensor in a vertical position. The entire assembly is mounted on a rotation table, maintaining the sensor orientation at the same heading.

Key Benefits of the System Include:

  • High precision 3-axis Schuler-tuned platforms with vertically constrained sensing element limits contamination from horizontal accelerations
  • NRG’s patented temperature stabilisation system greatly reduces system drift
  • Phase information from dual frequency DGPS provides accurate aircraft velocity measurement
  • Improved production
  • Less susceptibility to turbulence
  • Consistent data quality

Although most sedimentary basins produce significant long-wavelength negative gravity anomalies, resolving basin structure is far more challenging, requiring improvements in both resolution and accuracy. As resolution is proportional to aircraft speed, the choice of a suitable slow flying aircraft platform will provide a significant improvement to data resolution.

The XTract™ system is employed on a Pilatus PC-6 Turbo Porter STOL aircraft, renowned for its safety and ability to fly slowly, this aircraft presents an ideal gravity platform.

The Porter is fully capable of operating from different types of unprepared, rough and short airstrips, in remote areas, at high altitudes and in all climates. A simple but solid construction, proven systems and features, combined with precision workmanship result in the highest reliability and lowest maintenance possible.


Technical Specifications

Magnetic Platform
Type Total Field
Typical noise envelope 0.001nT/m SDEV 4th diff
Aircraft Type Pilatus PC6 (“Porter”)
Engine Type Turbine PT6-27
Fuel Type JetA1
Acquisition System
CPU Pentium 4 800Mhz
Operation Temperature -10 to 65 Degrees C
Standard Sampling Rate 20 Hz
Magnetometer Counter
Type NRG RDAC ll
Counter Frequency 1000Hz
Internal System Noise <0.0001 nT
Adc Inputs 10
Magnetometer Inputs 8
Recording Rate 20 Hz
Magnetometer Sensor
Type Scintrex CS3
Measurement Range 15 000 – 105 000 nT
Noise Envelope 0.002 nT
Gradient Tolerance 40 000 nT/m
Operating Temperature  -40 to +50 Degrees C
Recording Rate 20 Hz
Sensitivity 0.0006nT Hz RMS
Fluxgate Magnetometer
Type Bartington
Analogue output +- 10 V
Linearity error <0.0015%
Calibration accuracy -0.005
Bandwidth 0.3 KHz
Internal noise <6 pTrms/Hz @1Hz
Recording rate 20 Hz
Base Station Magnetometer
Manufacturer NRG Engineering
Range 15 000 to 105 000nT
Sensitivity 0.0006nT Hz RMS
Recording Rate 1Hz
GPS Base Station
Type Novatel DL-V3 OEMV L1,L2
Code Tracked L1 C/A, L2 P(Y), L1 Carrier Phase, L2 Carrier Phase 
Recording Rate 2Hz
No. of Satellites 12
Gravity Meter
Type GT1A/GT2A
Channels 3
Trigger External GPS
Recording Rate 2 Hz
Measurement Range ± 0.25 g, ± 0.5 g and ±1.0 g
Type Vaisala
Sample Rate 20 Hz
Pressure Resolution 0.001 mb
Operating Pressure Range 600 – 1060 mb
Recording Rate 20 Hz 
Type Vaisala
Sample Rate 20Hz
Resolution 0.05 DegC
Accuracy 0.1 DegC
Recording Rate 20 Hz
Radar Altimeter
Type Free Flight 
Operating range 0 - 762 m
Accuracy 0 - 10 m ±0.3m
Accuracy 10 - 762 m ±0.5%
Recording rate 20 Hz
GPS Navigation
Type Novatel DL-V3 OEMV L1,L2
Differential Correction Real Time
Code Tracked L1 C/A, L2 P(y)
Number of Satellites 12
Recording Rate 10 Hz Triggered
Processing Software Platforms Geosoft Oasis Montaj, Waypoint GrafNav,GTGRAV and GTNAV, Propriety Software