Raster versus Vector Map Data





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


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.