GPS: Global Positioning System

GPS:Global

Positioning System

Wildlife Management 20/30

Feasibility studies begun in 1960’s. Pentagon appropriates funding in 1973. First satellite launched in 1978. System declared fully operational in April, 1995.

The History of GPS

How do you use these satellites to calculate your position?

The Global Positioning System is a constellation of 31 satellites that is used to calculate your position.

Control Segment

Space Segment

User Segment

Three Segments of the GPS

Monitor Stations

GroundAntennas

Master Station

Kwajalein Atoll

US Space Command

Control Segment

Hawaii

Ascension Is.

Diego Garcia

Cape Canaveral

Ground AntennaMaster Control StationMonitor Station

Control Segment

Space Segment

User Segment

Three Segments of the GPS

Monitor Stations

GroundAntennas

Master Station

Space Segment

Control Segment

Space Segment

User Segment

Three Segments of the GPS

Monitor Stations

GroundAntennas

Master Station

Military. Search and rescue. Disaster relief. Surveying. Marine, aeronautical and terrestrial navigation. Remote controlled vehicle and robot guidance. Satellite positioning and tracking. Shipping. Geographic Information Systems (GIS). Recreation.

User Segment

Position is Based on Time

T + 3Distance between satellite and receiver = “3 times the speed of light”

T

Signal leaves satellite at time “T”

Signal is picked up by the receiver at time “T + 3”

Sources of Signal Interference

Earth’s Atmosphere

Solid Structures

Metal

Electro-magnetic Fields

Waypoint A waypoint is based on coordinates entered into a GPS

receiver’s memory. It can be either a saved position fix, or user entered

coordinates. It can be created for any remote point on earth. It must have a receiver designated code or number, or

a user supplied name. Once entered and saved, a waypoint remains

unchanged in the receiver’s memory until edited or deleted.

Getting Started…• 5 buttons:

o Powero Page (also the “back” function)o Entero Upo Down

Getting Started…• Power the GPS on: Hold the Power Button

• It will prompt you if you are indoors, select: YES by pressing the up/down and enter keys.

• Keep selecting the “Page” button until you get to the MENU screen. You know you’re there when the following options are shown:o Marko Waypointso Routeso Trackso Setup

Getting Started…• Scroll down to Mark, and select it with the Enter

key.

• It will prompt you to Mark Waypoint, before you select YES with the Enter key, use the UP arrow to the Number: 001 Change this to the title school. Once that is titled, scroll down to highlight the OK and select it with your Enter key.

• Write down the Elevation:• Write down your bearing:

o N__*__.___`o W___*__.___`

Marking Way Points• You and a partner are going to mark Way Points. • Head to the M and mark the Way Point as M. • Head to the closet field goal post on the football

field and mark the Way Point as Post.• Head to the water tower and mark the Way Point

as Blue.

• **It is critical that you label your Way Points!!!**