Maps and Globes

Geographer use two- and three-dimensional tools to learn about the earth.

Geographers use computer-assisted technology to study the earths surface.

Maps and Globes Globe- three dimensional

representation of the earth.•Benefits- most accurate•Deficiency- not portable

Map- Two-dimensional•Benefit- portable•Deficiency- distortion of landmasses

Map Projections A map projection is a way of drawing

the earths surface that reduces distortion caused by presenting the round earth on a flat surface.

Robinson Projection

Cylindrical projection: Shows the entire earth with nearly true sizes and shapes of the continents and oceans but landforms at the poles appear flat.

Mercator Projection

Cylindrical projection: the shapes of the continents are distorted at the poles and compressed at the equator.

Sinusoidal Projection

Conical Projection

Conical projections distort the size and shape of landmasses at the edges of the map.

Homolosine Projection

Cylindrical map: Shows accurate shapes and sizes of landmasses but the distances are not correct

Types of Maps

Topographic map: representation of natural and man-made features on the surface of the earth.

Thematic map Thematic Maps emphasize specific

information such as climate of population.

Mapmaking

Step 1: Surveying: data is gathered by a series of satellites and aerial photography.

Landsat- series of satellites Geostationary Operational Environment

Satellite (G.O.E.S)- weather satellite

Mapmaking Step 2: Data is recorded and

converted into a gray image (pixels).

Then mapmakers (cartographers) use this data and computer software converts the pixels into usable images to construct maps.

Geographic Information System

GIS stores information about the world in a digital database. Mapmakers, researchers, geographers etc… can log into GIS and combine information from a variety of sources to create a specific map. http://www.geodata.gov/

What is GISSimply put, a GIS combines layers of information about a place to give you a better understanding of that place. What layers of information you combine depends on your purpose—finding the best location for a new store, analyzing environmental damage, viewing similar crimes in a city to detect a pattern, and so on.

Global Positioning Satellite GPS : A system originally developed by the

military, this system of 24 Navstar satellites beam information to the earth. It sends information about absolute location using longitude and latitude coordinates as well as altitude and time.

This technology is now being used by hikers, joggers, sea captains and drivers to determine exact location. The Onstar navigation system in cars is a good example.