1. Ch2 Sec3 Maps and Computers

2. Key Concepts • How does computer mapping differ from earlier ways of making maps? • What sources of data are used in making computer maps?

3. Key Terms • Surveying • Digitizing • Satellite image • Pixel • Global Positioning System

4. Ch2 Sec3 • Surveying: mapmakers determine distances and elevations using instruments and the principles of geometry • With computers, mapmakers can store, process, and display map data electronically • Digitizing: the process by which mapmakers convert the location of map points to numbers

5. Ch2 Sec3 • Computers produce maps using data from many sources, including satellites and the Global Positioning System • Satellite images: pictures of the surface based on data • Pixels: a satellite is made up of thousands of tiny dots • GPS: is a method of finding latitude, longitude, and elevation of points on Earth’s surface using a network of satellites