Portable Ice-Pilot Unit Converts Satellite Data into Actionable Information
An article by Dr. Lasse Rabenstein, CEO at Drift & Noise Polar Services GmbH
Radar satellite images are widely accepted as the most valuable tool for navigation in ice infested waters. With them the experienced ice pilot can extract information about the position and type of marine ice in the working area independent of daylight and clouds. The only pain with such images is their large file size and a cumbersome data handling. Unfortunately, the internet connection on board ships is magnitudes slower than what we are used to on land and in the high latitudes of the Arctic the bandwidth is even further decreased. Two of the MarSat partners, Drift & Noise Polar Services GmbH and TRENZ GmbH, addressed that problem and developed a portable ice-pilot unit.
The basic functionality of the so-called Ice-Pad is the visualization of satellite radar images and other ice information on a chart display. But its unique functionalities are the optimization for a low bandwidth environment, the near-real time availability of images and an image-on-demand button. With the Ice-Pad software installed on board, administrative work to organize an excellent ice information level on board is no longer needed, neither before nor during a cruise.
The Ice-Pad prototype was tested as part of the MarSat project by Hapag-Lloyd Cruises during an expedition cruise in the North-West Passage and by FUGRO Hydrographic Surveys during surveying work close to the Svalbard archipelago.
Both test users appreciated the low bandwidth functionality. With the Ice-Pad only the interesting part of a satellite image is transferred on board, in a resolution optimized for the needed level of detail and only if the user considered the image new enough. That makes the Ice Pad functional even in regions where the only available satellite communication is IRIDIUM. Nicole Schnell, nautical officer on the MS Hanseatic commented: “The Ice-Pad enabled us to receive satellite images during our northern most section of the cruise: The Nares Strait between Greenland and Ellesmere Island where broadband satellite internet connections do not work.”
Within the Ice-Pad Sentinel-1 radar images are available within 2 to 4 hours after satellite recording, 24 hours a day, 7 days a week. This near-real-time feature is guaranteed by the automated Ice-Pad backend system which runs on servers with a broadband internet connection to the Copernicus Marine Environmental Monitoring Service (CMEMS). All potentially interesting Sentinel-1 images are enhanced, cut to the region-of-interest and rescaled to different resolutions and are available for the frontend system to be fetched on demand.
A voyage into the ice infested waters of the polar regions cannot be planned in beforehand in all its details. Flexibility is needed to adapt the course to changing ice conditions. Often different regions are suddenly of interest than anticipated before the voyage. That is the reason why the Ice-Pad system divides the Arctic map into a grid of smaller tiles. On demand, satellite images can be obtained by clicking on a tile in a part of the Arctic map which was not anticipated to be of interest before the voyage.
This follows a three-step approach
- Check for data availability and the date of the newest available Sentinel-1 scene available for that tile (download of a few bytes only).
- Download a preview image (50 - 120 Kbyte)
- Download a full scale image (2 -3 Mbyte)
The Ice-Pad prototype delivers the basic concept and is the nucleus for a comprehensive ice information system in the future. The idea is, that useful ice information products will be available on board with the same matter of course as nautical charts. The MarSat consortium invites interested test users of the Ice-Pad software to contact us.
Figure 1: Captain Thilo Natke of the MS Hanseatic uses the Ice-Pad prototype system during a voyage into the Canadian North West Passage (Copyright Hapag-Lloyd Cruises GmbH).
Figure 2: The MS Hanseatic operated by Hapag-Lloyd Cruises. (Copyright by Hapag-Lloyd Cruises GmbH)