Students must be able to identify and understand the following projections. • Mercator • Polar • Robinson
Mercator Projection Most Accurate in the tropics from Cancer to Capricorn Most Distortion at the North and South Poles
Mercator Projection • Used for: • Locating Latitude and Longitude • Sea Captains use it for navigation at sea
Mercator Projection • Characteristics: • All lines are at 90 degree angles • Simplest to read • Accurate direction • Distorted size, distance, shape
Robinson Projection Most Accurate at the equator Most Distortion around the outer edges
Robinson Projection • Same characteristics as the Mercatorexcept: • lines of longitude are curved • shapes at the poles are flat and not as distorted • used mostly in classrooms--one of the most accurate maps
Polar Projection Most Accurate at the poles Most Distortion around the outer edges
Polar Projection Used for navigation of air planes
Polar Projection • Characteristics: • Distances and direction are accurate from the center along the longitude lines. • Size and shape are accurate at the center of the map
Types of Maps Conic Projections • A conic projection is a map made by projecting points and lines from a globe onto a cone. • The cone touches the globe at a particular line of latitude along which there is very little distortion in the areas or shapes of landmasses. • Distortion is evident near the top and bottom of the projection.
Types of Maps Gnomonic Projections • A gnomonic projection is a map made by projecting points and lines from a globe onto a piece of paper that touches the globe at a single point. • Gnomonic projections distort direction and distance between landmasses. • Gnomonic projections are useful in plotting long-distance trips by air or sea.
Types of Maps Gnomonic Projections • Great circles are imaginary lines that divide Earth into two equal halves. • On a sphere such as Earth, the shortest distance between two points lies along a great circle. • Navigators connect points on gnomonic projections to plot great-circle routes.