Geography & Technology Global Positioning System “GPS” CGC1D – Unit 1 – Chapter 3

GPS (Global Positioning System) The GPS (Global Positioning System) is a "constellation" of 24 well orbit the Earth and make it possible for people with ground receivers to pinpoint their geographic location. The location accuracy is anywhere from 100 to 10 metres for most equipment. Accuracy can be pinpointed to within one metre with special military-approved equipment.

GPS (Global Positioning System) GPS equipment is widely used in science and has now become sufficiently low-cost so that almost anyone can own a GPS receiver. The GPS is owned and operated by the U.S. Department of Defense but is available for general use around the world.

GPS (Global Positioning System)

GPS (Global Positioning System) A hand-held GPS units

GPS (Global Positioning System) An in-dash (vehicle) GPS unit

GPS (Global Positioning System) Phone GPS apps

Aerial Photographs Using the photographs of the Earth taken by airplanes, you can see the world in 3D using a stereoscope.

Aerial Photographs Google Earth shows aerial photographs in a digital format, with a general purpose map on top.

Satellite Imagery Satellite images are also pictures of the Earth taken from above, but these electronic images (instead of photographs) cover very large areas but show less detail. Landsat was developed by the Americans and uses sunlight and heat reflected from the Earth’s surface to create images SPOT was developed by the Europeans and similar Landsat, but it can create 3D images of the surface RADARSAT was developed by the Canadians and uses radar signals (or microwaves) instead of sunlight and heat, so it can be used at any time of day or night

GPS – Uses and Concerns What are some positive uses for GPS? What are some possible concerns we might have for using GPS?