Ice Probe and Ice Pic

Fixed-mount EM probe

Fixed-mount EM probe

Towed sensor

Towed sensor

Diagram of a "Bird" being towed by a Helicopter

Diagram of a "Bird" being towed by a Helicopter

The Ice Probe consists of a cylindrical sensor package, or "bird", which is towed 30 m beneath a helicopter at between 15 and 30 m above the ice surface. The bird is 4 m long and weighs about 125 kg. The tow cable supplies power from the helicopter to the sensors in the bird and transmits data from the bird to the data logger in the helicopter.

Fixed-mount EM probe

Fixed-mount EM probe

The Ice Pic is a fixed-mount EM sensor that measures ice thickness. The overall weight of the fixed-mount sensor package is 44 kg and consists of the laser, an EM transmitter, and an EM receiver mounted inside a cylindrical tube that is fitted to the nose of the helicopter. The EM induction system uses 4 frequencies: 1.67, 5.02, 11.7, and 35.1 KHz, to measure the distance to the ice-seawater interface. The laser measures the distance to the surface of the pack ice. The EM footprint is about 2.5 times the sensor altitude above the seawater surface.

The system can be used to "spot sample" by soft-landing and averaging the incoming 10 Hz data, or it can be used to profile floes by slowly flying at low altitude. The Ice Pic console runs on 28-volt helicopter power, and, in addition to the EM laser data, it logs GPS position and radar altimeter data derived from the helicopter's avionics. The real-time outputs are snow and ice thickness, ice conductivity, and the laser altitude.

onboard system console

The onboard system console is strapped into the back seat of the helicopter and logs the data.

hand-held operator's control unit

The hand-held operator's control unit is shown on the front seat of the helicopter with the power and GPS input connectors to the helicopter visible in the background.

In EM systems, a transmitter coil generates a primary magnetic field using frequencies between 20 and 90kHz. This induces eddy currents in a nearby conductor, in this case, seawater. These currents, in turn, generate a secondary magnetic field which is sensed by the receiver coil near the back of the bird. The amplitude and phase of the secondary field relative to the primary field are used to estimate the distance between the sensor and the surface of the ocean, and the laser altimeter measures the distance to the ice or snow, if it is present. The difference between the two distances gives the ice-plus-snow thickness, referred to as "EM-measured ice thickness". The altimeter is also used to measure the surface roughness.

Results

Plots

Plots

Ice Drift

Ice Drift

The Ice Probe and Ice Pic data are sent from the field via e-mail to co-investigators as plots and as data files. The data files can be accessed by using viewing software that is capable of zooming data sections and displaying profiles and histograms of ice thickness, ice draft, or surface roughness.

Related Publications

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  • Belliveau, D. J., H. Hayden, and S. J. Prinsenberg. 2001. "Ice Drift and Draft Measurements from Moorings at the Confederation Bridge"
  • Holladay J. S. 1995. Analysis of Electromagnetic/Laser Data Over the Newfoundland Shelf
  • Holladay, J. S. and S. J. Prinsenberg. 1999. Airborne Electromagnetic Sea Ice Sounding Measurements During 1998 Gulf of St. Lawrence Field Program
  • Holladay, J. S., B. Lo, and S. J. Prinsenberg. 1997. "Bird Orientation Effects in Quantitative Airborne Electromagnetic Interpretation of Pack Ice Thickness Sounding"
  • Holladay, J. S., R. Moucha, and S. J. Prinsenberg. 1997. Analysis of Electromagnetic/Laser Data over the Labrador Shelf 1994
  • Holladay, J. S. and S. J. Prinsenberg. 1999. Airborne Electromagnetic Sea Ice Sounding Measurements During 1997 Gulf of St. Lawrence Field Program
  • Holladay, J. S. and R. Moucha. 1998. Electromagnetic/Laser Ice Thickness Data from the Labrador Shelf, 1994
  • Holladay, J. S. 1999. Airborne Electromagnetic Sea Ice Sounder Operational Sensitivity and Error Analysis
  • Moucha, R. Z., J. S. Holladay, and S. J. Prinsenberg. 1998. Airborne Electromagnetic Sea Ice Sounder Measurements of RADARSAT Validation Project 1996
  • Peterson, I. K., S. J. Prinsenberg, and J. S. Holladay. 1997. "Comparison of Electromagnetic Sea Ice Thickness Measurements with RADARSAT Imagery in the Gulf of St. Lawrence"
  • Peterson, I. K. and S. J. Prinsenberg. 1996. "Ice Drift and Electromagnetic Ice Thickness Measurements in the Gulf of St. Lawrence during the 1996 RADARSAT Validation Experiment"
  • Peterson, I. K., S. J. Prinsenberg, and J. S. Holladay. 1999. "Using a Helicopter-Borne EM-Induction System to Validate RADARSAT Sea Ice Signatures"
  • Peterson, I. K., S. J. Prinsenberg, J. S. Holladay, and L. Lalumiere. 2000. "Mapping Sea Ice Properties with a Helicopter-Borne Electromagnetic-Induction and Video System"
  • Peterson, I. K., S. J. Prinsenberg, J. S. Holladay, and L. Lalumiere. 2000. "Mapping Sea Ice Thickness with RADARSAT and a Helicopter-Borne Electromagnetic-Induction System"
  • Prinsenberg, S. J., I. K. Peterson, and A. Maillet. 1998. "1997 Pack Ice Properties in Northumberland Strait"
  • Prinsenberg, S. J., I. K. Peterson, and A. van der Baaren. 1996. "Comparison of Labrador Pack Ice Observations with RADARSAT Imagery during March 1996"
  • Prinsenberg, S. J. and I. K. Peterson. 2001. "Pack Ice Thickness and Concentration Measurements from the Area Around Confederation Bridge (Canada) Using Helicopter-borne Sensors"
  • Prinsenberg, S. J. and I. K. Peterson. 2003. "Comparing ice chart parameters against ice observations"
  • Prinsenberg, S. J., S. Holladay, and J. Lee. 2002. "Measuring Ice Thickness with EISFlowTM, a Fixed-mounted Helicopter Electromagnetic-laser System"
  • Holladay, J. Scott. 2006. Application of Airborne and Surface-based EM/Laser Measurements to Ice/Water/Sediment Models at Mackenzie Delta Sites
  • Peterson, I. K., S. J. Prinsenberg, and J. S. Holladay. 2008. "Observations of sea ice thickness, surface roughness and ice motion in Amundsen Gulf"
  • Prinsenberg, S. J., I. K. Peterson, and Scott Holladay. 2008. "Measuring Freshwater-layer Plume Depths and Ice Thicknesses of and Beneath the Land-fast Ice Region of the Mackenzie Delta with Helicopter-borne Sensors"
  • Peterson, I. K., S. J. Prinsenberg, J. Hamilton, and R. Pettipas. 2008. "Variability of Oceanographic and Ice Properties of the Canadian Arctic Archipelago"
  • Holladay, S., S. Prinsenberg, and I. Peterson. 2010. "Measuring Arctic Nearshore Properties with a Multi-Frequency Airborne Electromagnetic Sensor".