The EM-Bird is a sensor used to determine the thickness of sea ice by helicopter or aeroplane
The EM-Bird is a sensor used to determine the thickness of sea ice by helicopter or aeroplane. Using the aerogeophysical electromagnetic (EM) induction method, the sea-ice thickness is determined on the basis of the electrical conductivity of the surface. In this regard, the major contrast in electrical conductivity between seawater and sea ice is used to determine the distance between the EM instrument and the underside of the ice. An additional laser-based method is used to measure the distance to the surface of the ice; the difference between the two readings is the thickness of the sea ice and snow cover. Read more about the EM-Bird here.