Raster versus Vector Map Data
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Advantages |
Disadvantages |
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Raster |
Direct copy of familiar paper product, with same accuracy and reliability Cheaper and simpler to produce, widely available Does everything paper chart does, and more Can emulate most vector functions Can add alarms manually |
Clutter when overlaid with other information No automatic depth alarms Cannot be interrogated (just a dumb picture) Cannot easily be rotated to heads-up orientation Generally larger memory requirements |
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Vector |
Display layers selectively User can tailor chart display Zoom in and out Set own safety and alarm depth Interrogate for additional information Can rotate Easier to integrate with other data, radar displays |
More complex, more cost, longer to produce ECDIS standards not finalized Large areas unlikely to be available for many years Users will need additional training More difficult to ensure quality |
Adapted from Dawson, J. (1997). Digital charting, now and in the future. Journal of Navigation, 50, 251-255. Dawson is from the U.K. hydrographic office, but these are his opinions and not Her Majesty's government.