Ice detection with FLIR Systems thermal imaging cameras
by Drew Valentine on 27 Feb 2012
The earth's polar regions are considered by seafarers to be among the most challenging environments on the planet. Thanks to FLIR Systems thermal imaging cameras can help today's arctic mariners find the safest way through the ice.
Glacier ice is difficult to track by marine radar as the signal is scattered by air bubbles and other imperfections in the ice. Many experienced seafarers know the difficulties in detecting ice with radar. Even the radar signal returns from large icebergs are much lower than from ship targets because the lower radar reflectivity of ice (and especially snow) compared to steel.
Pieces of ice also break from icebergs known as bergy bits or growlers. The smaller growlers are even harder to detect by radar especially in heavy seas. During daylight hours the inability of radar can be compensated by visual inspection but thise relies on clear conditions. But what happens at night or in fog or snow?
The solution is in the use of thermal imaging cameras which record the intensity of electromagnetic radiation in the infrared spectrum. All matter emits infrared radiation - even ice. In a thermal imaging camera the infrared radiation is focused by a lens onto the detector. The intensity of the recorded infrared radiation is translated into a visual image. Because thermal imaging cameras rely on thermal contrast instead of colour contrast they do not need lighting to produce crisp images during the night. They provide an overview of the situation giving a much better idea of the surroundings than the narrow beam of a searchlight.
Ice detection tests were carried out by FLIR in Greenland using the FLIR models M-612L and M-625L. The FLIR M-Series thermal imaging camera is available with a variety of sensors and resolutions to meet a wide range of maritime needs.