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GPS & GISGPS & GIS

Quick QuizQuick Quiz

• What Do GPS & GIS Stand For?• How much does it cost?

AnswersAnswers

• What Does GPS Stand For? - Global Positioning System

• What Does GIS Stand For?– Geographic Information System

• How Much Does it Cost?– The service is free.

DesignDesign

• 3 segments: Space, Control, User– Space segment made of 24

satellites orbiting the Earth.

– Control consists of engineers organizing the flight plan

– Users, like you and me, have receivers that contact the satellites for information on location.

How GPS WorksHow GPS Works

• User requests GPS information

• GPS sends response with time

• GPS receiver calculates location based on response time

Common ApplicationsCommon Applications

• Outdoorsmen/women use GPS

• Smart Bombs, Cruise Missiles, and other million dollar explosives use GPS

• Vehicles started to use GPS

• Police uses it for vehicle tracking

• Surveyors use it to determine boundaries, area elevations of land, etc

Common Applications

• Farmers use GPS to survey their fields so that they can distribute fertilisers more efficiently

• Airline pilots use GPS • Zoologists attach

miniscule GPS receivers to animals like dolphins & polar bears to study their behaviours in their natural habitats

GPS In VehiclesGPS In Vehicles

• DVD Navigation– DVD + GPS Information

= Interactive Map

• Pros– Harder to get lost– You look cool

• Cons– Expensive– Talking voices are

annoying

GIS

Refers to Geographic Information System

GIS allows you to store, visualize, and manipulate data provided to it through GPS and other data collection tools.

How are GPS & GIS related?How are GPS & GIS related?

GPS is a data gathering tool, and GIS allows you to store, visualize, and manipulate dataprovided to it through GPS and other data collection tools

GIS stores data and uses satellite imagery or aerial photographyas a basemap for the overlay of these layers. Each layer can store vast amounts of information, such as soil types, crops, land boundaries, place names, and populations.

Collecting a Point FeatureCollecting a Point Feature

• The first new feature you need to record is a road sign. This is a point feature.

• To record a point feature, you remain stationary while the TerraSync software logs GPS positions.

• These positions are averaged to compute the final GPS position of the point feature.

Collecting a Point FeatureCollecting a Point Feature

• When the TerraSync software is logging GPS positions, the logging icon appears in the status bar.

• The number beside the icon indicates how many positions have been logged for the selected feature.