Ice Penetrating Radar System

Icefield Instruments Inc. manufactures pulse radar transmitters based on the Narod transmitter (Narod, 1994). This transmitter is very small and portable, consumes little power, yet is capable of measuring ice thicknesses of 300m (temperate ice) to 800m (cold ice).

Components

Icefield Instruments Inc. can provide impulse radar systems consisting of any or all of the following components:

Transmitter

Narod Geophysics-type broad-band transmitter fitted with power and antenna terminals³.

Modified "slow" transmitter using MOSFET triggers offers a slower rise time suitable for lower frequencies (below 5MHz). Useful in thicker and/or warmer ice. Return signals will generally have less surface clutter owing to the lower frequencies (e.g., less noise from crevasses).

Antennas

5m resistively-loaded dipole antenna (overall length 10m); 8-10MHz nominal frequency (receive/transmit).¹ - CAD $690/set

10m resistively-loaded dipole antenna (overall length 20m); 4-5MHz nominal frequency.¹ - CAD $780/set

Custom antennas are available. The formula to compute the antenna arm length for a specific centre frequency is h=42/f where h is the length of a dipole arm in metres and f is the centre frequency in MHz (this formula assumes an ice velocity of 168m/µs). The overall length of each antenna will be twice the computed value of h. Available centre frequencies range from 1MHz to 70MHz. - please contact us for pricing

Optional webbing jacket for dipole antennas.² - CAD $150/set

Accessories

45m optical fibre cable and pulser unit which serve to synchronize the transmitter and receiving oscilloscope, thereby removing reliance on air-wave triggering.³

50 Ohm terminator for receiving antenna (improves impedance matching and noise immunity; particularly useful for shallow ice). - CAD $170

Prices do not include shipping, duty, or taxes. The harmonized commodity codes for radar transmitters is 8526.10.00.90 and for aerials and accessories is 8529.10.00.91.

NOTE: This page may be printed and used for formal quotation purposes. Prices are provided here for that purpose, and to save us time and effort better spent on other tasks. Prices are guaranteed to be current. If your institution insists on a formal price proposal, we charge an additional $50 documentation fee. Delivery times and estimated shipping costs are quoted without cost via email. We can email you the operations manual if you need more information (available in English and Spanish).

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Transmitter Specifications

• Peak power: 24kW, ~1.1kV into 50 Ohm
• Rise time: < 2ns (standard transmitter)
• Pulse repetition rate: 512Hz
• Power consumption:
• Standby: 5mA at 10-14VDC
• Active: 180mA at 10-14VDC
• Dimensions: 110mm x 82mm x 44mm
• Weight: 200g

Receiver Options

Software Oscilloscope

Blue System Integration Ltd. has developed a software oscilloscope solution that includes software to produce and display radar sections in the field. Please contact Laurent Mingo for pricing information and support. Radar components may also be purchased through Blue System Integration.

Hardware Oscilloscope

We recommend that users choose one of the following portable oscilloscopes as receivers. Although Icefield Instruments may be able to provide customers with these units, we suggest that you contact local suppliers. If you cannot find any scopes on this list (several are obsolete), look for a scope that can provide 2-5mV/division on time scales of 500ns/div to 2µs/div. Since the radar signal is repetitive, the ability to average signals (available on digital scopes) is an advantage.

• Textronix 222 or 224 (glass CRT - better cold-weather performance)
• Textronix TekScope (backlit LCD display)
• Fluke Scopemeter 90 or 100 series (backlit LCD display - better visibility in bright sun)

Product Packing Lists

• Radar Transmitter
  • transmitter unit (requires 10-14 VDC @ 200mA max.)
  • 30cm power cable (default termination is bare wire - please specify if you wish alternative termination)
• Pulser Unit
  • pulser unit (requires 9-14 VDC @ 50mA)
  • 50m fibre-optic cable with terminations, installed in 45m of 25mm tubular webbing
  • 60-90cm (2-3ft) BNC jumper cabe to connect pulser to receiver's external trigger input
  • 30cm power cable (default termination is bare wire - please specify if you wish alternative termination)

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Notes

1. Antennas are constructed of rubber test lead wire with excellent cold-weather properties.
2. For improved handling, antennas may be sheathed in 25mm colour-coded military-grade tubular webbing. This sheath is not recommended for wet environments because the antenna may be damaged should it be handled when the sheath is frozen. This option costs an additional $150 per antenna set.
3. Power supply for the transmitter and optical pulser is a nominal 12VDC. 30cm-long power leads without termination are provided.

References

Jones, F.M.H., Narod, B.B., and Clarke, G.K.C., 1989. Design and operation of a portable, digital impulse radar, J. Glac., 35(119), p.143-148.

Narod, B.B. and Clarke, G.K.C., 1994. Miniature high-power impulse transmitter for radio-echo sounding, J. Glac., 40(134), p.190-194.

Shen, L.C. and King, R.W.P., 1965. Correction to the Cylindrical Antenna With Nonreflecting Resistive Loading by Wu and King, IEEE Trans. on Antennas and Propagation, AP-13, No. 6, p.998.

Wu, T.T. and King, R.W.P., 1965. The Cylindrical Antenna With Nonreflecting Resistive Loading, IEEE Trans. on Antennas and Propagation, AP-13, No. 3, p.369-373.