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Encyclopedia of Marine and Energy Technology

Electronic chart display and information system (ECDIS)


The newly developed navigational tool using digital charts (vectorised and raster charts) for navigational tasks normally carried out with paper charts. The equipment must be type-approved and uses up-to-date official charts. As long as the area covered by vector charts (ENC) is small, the ecdis should be able to cover both vector and raster (RNC) charts. When operating in raster mode, an ecdis must be used together with an appropriate folio of up-to-date paper charts.

North up/heads capability of ecdis: In the normal north up mode the ship moves across the static chart until it approaches the edge of the screen when a new section of the chart is automatically displayed. In heads up the vessel remains in the center of the display while the chart moves underneath. The vessel always appears up on the display with the image automatically rotated to the correct orientation, thereby matching the scene outside the window.

Radar overlay – A navigation system which superimposes live radar video output over ecdis. It provides a scan-converted output for display, automatically scaled to suit the displayed chart. The transparency can be adjusted so that the chart can be seen through the radar image. The overlay and its controls conform to ecdis standard for combining radar with ecdis chart display.

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