Digital Map Compilation and Desktop Mapping

SP 240 CartographyAlex Chaucer

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Terms to go over for this chapter

• CRT• DEM• Digitizer• DRG• DOQ• graphical user interface (GUI)• Hard copy• Peripherals• plotter

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CRT

• Cathode-ray tube• Aka computer monitor

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DEM

• Digital Elevation Model• Raster data where each cell has an

elevation value as a z-value• From it can create

Hillshade Slope Aspect 3D elevation

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Digitizer

• Devices to convert analog images into digital representation

• Also, a person who is digitizing

http://www.aircraftcovers.com/media/digitizer.jpghttp://www.advancedgis.ca/workdir/images/digitizer.jpg

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DRG

• Digital Raster Graphics• Scanned image of USGS topo map

http://tahoe.usgs.gov/images/4ds/drg_zoom.gif

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DOQ

• Uniform Aerial Photos from USGS• Digital Ortho Quad

http://erg.usgs.gov/isb/pubs/factsheets/fs05201.graphics/doq.gif

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graphical user interface (GUI)

• The interface between the user and the computer

• Often includes menus, buttons, display screen, etc.

• The ArcMap and ArcCatalog screens are each GUI for the ArcGIS Desktop software

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Hard copy

• Printed copy of machine output that is in readable form

• Ie. A paper map• Softcopy would be a map as a digital file,

such as a jpeg or a pdf

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Peripherals

• Associated equipment coupled to the computer (printers, plotters, scanners…)

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plotter

A plotter is a device that develops an image (map) by controlling pen movement over the output medium

Also used for large format printers

http://www.encad.com/seo_images/body/r1c2_t-200.gif