AIRBORNE – QAMT – Full-Tensor Magnetic Gradiometry

Introducing the QAMT System

The QAMT system is a lightweight helicopter-borne AFMAG (magnetovariation tellurics) survey system, which passively measures the earth’s response to naturally-occurring electromagnetic fields. The system delivers low-noise, 3-component mobile data using LT SQUID (superconducting quantum interference device) sensors that are capable of acquiring unparalleled data quality.

Over the last decade, natural field airborne EM methods have advanced significantly. They are known to provide valuable subsurface information for deep targeting and large-scale mapping. Single component passive EM systems do not provide adequate levels of certainty in resistivity imaging. The QAMT, with low-noise and 3-component mobile acquisition, now provides a new standard of resolution and depth capability for this airborne method. Data sets can be acquired with greater confidence and will deliver a clearer and deeper imaging result.

The SQUID sensors are developed by Supracon AG of Jena, Germany. Operating within a liquid helium bath, the sensors measure the electromagnetic field with unrivaled sensitivity. The sensor system is the result of over 20 years of development and testing. SQUID sensors systems have revolutionized ground EM surveying, and we expect the same advantages will be seen in airborne applications.

The QAMT system can be used for MT surveying, 3 component magnetic surveying, and semi-airborne applications.

QAMT Advantages

  • Low-noise LT SQUID sensors
  • 3C H-field measurement
  • Lightweight towed bird
  • Full-tensor base station
  • Simultaneous 3 component magnetic data

QAMT Products

  • Apparent resistivity maps from surface to a depth
  • 2D and 3D resistivity models
  • High quality 3C magnetic products
  • Gradient maps Bx, By, Bz
  • 3D Inversion models

QAMT Specifications

  • SQUID sensor: 3 channels orthogonal
  • Noise: < 50 fT / √Hz)
  • SQUID electronic bandwidth: > 3 MHz
  • Operating temperature range: -10°C to +40°C
  • Cryostat operation: 2.5 days per refill
  • Data acquisition: 2 MS/s and SNR > 34 bit
  • IMU system: 3 fibre optic gyros, 3 accelerometer sensors
  • Radar altimeter: max of 3 % or 0.5 m
  • Laser altimeter: +/- 1 to 2 cm typical
  • Total bird weight: 267 kg
  • Tow rope: DyneemaTM – 32 m +