The initial ice thickness and compactness are from the digitized ice chart
of the Finnish Institute of Marine Research (FIMR 2006).
An accurate freeze-up date could not be determined for the points located in the latter two regions (points 1, 3, 9, 13, 14, and 19) because in many consecutive years freeze-up had not yet occurred when the CIS published its last weekly ice chart
of the season.
Fresh satellite images and ice charts
has made it possible to update the voyage plan continuously thus enabling KV Svalbard to find the best route through the ice.
The CISDA is a collection of CIS's daily operational ice charts
, regional ice analysis charts, and weekly ice thickness and on-ice depth measurements.
In waters with unreliable ice charts
, that can pose big problems.
Therefore, vessel captains would need to rely on marine surveys and ice charts
. For some areas in the Arctic, however, these surveys and charts are out of date and not sufficiently accurate.
Ice thickness measurements in the Baltic Sea (Lepparanta & Hakala 1992) have shown that the amount of deformed ice is significantly larger than reported in routine ice charts
and the mean ice thickness (taken over several square kilometres) could exceed consequently 2-3 m in wide areas of the Baltic Sea.
Recent ice thickness measurements in the Baltic Sea  have shown that the amount of deformed ice is significantly larger than reported in the routine ice charts
. Consequently, the mean ice thickness could exceed 1-2 m in large areas of the Baltic Sea.
Burning Ice charts
the voyages of climate change crusaders Cape Farewell, as Tamzin Lewis writes.
The CISDA is a compilation of Canadian Ice Service regional weekly ice charts
that integrate all available real-time information about sea ice gathered from various satellite sensors, aerial reconnaissance, ship reports, operational model results, and the expertise of experienced ice forecasters.