Chapter 3 Notes

Section 1-3

While You Read

1. Mercator ProjectionStrengths: shows whole world on one map, shows true directions as straight lines;

Weaknesses: distorts areas near poles

Latitude Lines |

Longitude Lines |

2. Gnomonic Projection:

Strengths: accurately shows shortest distance between two points; shows polar regions well;

Weaknesses: distorts land mass shapes away from center; shows only part of the Earth

Gnomonic

Gnomonic Stereographic Orthographic

3. Polyconic Projection

Strengths: landforms have true size and shape relation to each other; shows middle latitudes well.

Weaknesses: distorts areas at poles; shows only part of Earth

Polyconic

4. Globe

Strengths: most accurate representation of our three-dimensional planet;

Weaknesses: difficult to transport

After You ReadExplain the importance of map scales and

orientation.

Map scales allow you to determine real distances and relationships of the features on the map.

Orientation tells you direction, without which you cannot relate a map to the real places it depicts.

3.2 Mapmaking and Technology

While You Read1. Plane-table surveying: draw map from

highest point, using sighting device and visual observation.

2. Photos from airplanes: draw map by copying contours of land from aerial photos.

3.2 While You Read3. Radar: use radio signals to create

images regardless of weather.

4. Satellite imaging: use sensors to make images from light waves

5. GPS: combine computer and satellite technology to locate people or places anywhere on Earth

3.2 After You ReadExplain how weather might affect the

mapmaking technologies discussed in this lesson.

Weather could cause visibility problems for plane-table surveys and airplane photography. Weather has little effect on satellite and GPS technologies

3.3 Topographic MapsAfter You Read

1. Topographic map: map that shows the altitude of land

2. Uses: city planning, road engineering, resource search, outdoor recreation

3. Symbols: color and shape indicate natural and human-made features

4. Contour lines: connect points of the same elevation

5. Slope: distance between contour lines shows slope of the land.

Additional Questions

1. What device detects and records data from Earth’s surface?

2. In what form does the data travel?

3. What happens to the data once it is recorded?

Additional Questions

4. What does GIS and GPS stand for?

5. What are some uses for GPS?

6. Why would a hiker find topographic maps useful?

Answers

1. A scanner on a satellite.

2. As electromagnetic waves

3. Computers convert the data to code, then to pixels, and finally to usable images.

Answers4. GPS – Global Positioning System

GIS – Global Information Systems

5. Locate people and vehicles when they are lost, help someone find a route to a destination, and investigate scientific phenomena such as ocean currents, or help law enforcement create a database of deer/car collisions.

Answers

6. Hikers can use topographic maps to find their way relative to land features, avoid bodies of water and too-steep trails, and estimate how far they have to travel.