GIS: maps in layers

你需要知道的

• GIS stands for geographical information system: a computer system to capture, store, display and analyse data about places.
• Spatial data records where a feature is, as a point (a hospital), a line (a road) or a polygon (a county boundary).
• Attribute data describes the feature, such as a building's name, height or date, and is stored in a table.
• A GIS stores each type of feature in its own layer, such as buildings, streets or land use, and stacks layers to rebuild the real world on screen.
• Good results depend on good data: poor data in means poor answers out.

这个短片讲了

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