Summary27

# Summary27 - What you learned Geography 12: Maps and Spatial...

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Geography 12: Maps and Spatial Reasoning Lecture 27: Class Summary Professor Keith Clarke What you learned • Map geometry, construction and content • Practical map use, reading and navigation • Map representation • Cartometry and map analysis • Basics of cartography’s sister disciplines How you learned it • Textbook • Lectures • Gauchospace • Supplemental materials • Exercises in lab • Evaluations Maps and geodesy • For maps showing the whole earth, a sphere is fine • For detailed mapping, the ellipsoid is necessary • For extreme mapping, the geoid is necessary • This impacts the map’s DATUM • Location of places and their height change with the datum • In the USA, we usually use NAD83 (very similar to WGS84) based on GRS80

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Map scale • The map scale transformation is the first, and changes data about the earth into a representation at a particular scale • Don’t use the terms large and small scale • Most maps are between 1:1000 and 1:400M • RF = MD / GD • The paper strip trick works • Most maps are at standard scales, like 1:50 000 • Computer-based maps can be zoomed Map Projections • We can project onto a plane, a cylinder or a cone • We can orient the projection as equatorial, oblique or transverse • We can make the projection tangent or secant • No flat map can be both equivalent and conformal More projections • Many features of projections can be varied • Since no flat map can be both conformal and equivalent, all have distortion • We can customize where and how much error is in a projection • We can know and display the error • The smaller the extent the map covers, the less
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## This note was uploaded on 12/27/2011 for the course GEOG 12 taught by Professor Gautier during the Fall '08 term at UCSB.

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Summary27 - What you learned Geography 12: Maps and Spatial...

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