Canada • Singapore • India • South Africa A Neterwala Group Company

Helicopter Frequency-Domain EM

McPHAR’s helicopter-borne frequency-domain electromagnetic survey system is integrated around the HUMMINGBIRD EM sensor, which is available in a 5-frequency configuration, see the table below. The HUMMINGBIRD EM sensor, which is the heart of this system, can be simply described as a multi-frequency, multi-coil electromagnetic system, which measures the in-phase and quadrature responses from a number of coil-pairs installed in a tubular bird, towed beneath a helicopter. All components of the HUMMINGBIRD are digitally controlled, in fact, HUMMINGBIRD is 100% digital from front to back. 

Data is telemetered on a lightweight serial cable to the data acquisition console onboard the helicopter, where it is displayed on a LCD colour screen and recorded on hard disk.
Pilot guidance and DGPS navigation systems are integrated into the package together with a gammaray spectrometer (optional).  

A high-sensitivity cesium vapour magnetometer is installed inside the HUMMINGBIRD sensor airfoil.
Other flight control instruments include radar and barometric altimeters and a digital colour video imaging system.



  • Helicopter-borne frequency domain EM System - 5 frequencies ranging from 900 Hz to 35 kHz
  • Good contouring in rugged terrain with accurate anomaly positioning
  • All digital samples generated by HUMMINGBIRD provided as inphase and  quadrature measurements
  • Flown in conjunction with magnetics and (optional) radiometrics
  • DGPS navigation with pilot guidance
  • Radar and/or laser altimeter, barometric altimeter & digital colour imaging



  • Base & precious metals exploration
  • Minerals exploration
  • Geothermal mapping
  • Kimberlite exploration
  • Environmental engineering surveys
  • Sand and Gravel mapping
  • Ground Water exploration
  • Sea-ice thickness mapping
  • Mapping fresh water/salt water interfaces
  • Permafrost mapping
    HUMMINGBIRD EM system and a Bell 206 L Long Ranger helicopter in Romania.
HUMMINGBIRD EM system and a Eurocopter SA-315 LAMA helicopter in Venezuela. HUMMINGBIRD EM system and a Eurocopter AS350B2 helicopter in Greenland.