Coordinates of the Earth

I. Global Positioning Systems

A. GPS is a system of angular measurements or

precision grid lines drawn over maps and globes

describing positions on the earth’s

surface. B. The lines are

measured in degrees.

C. GPS was used by primarily by mariners, aviators, and the military.

D. These systems are now used world wide. (Do the pictures below give you any ideas how?)

II. GPS Jargon A. Latitude

1. Lines running horizontal to the

equator (east and west) called parallels.

2. 0° is the equator, the imaginary line dividing

our planet into the northern and southern

hemispheres.

3. The North Pole 90° N Latitude and the

South Pole 90° S Latitude

4. A degree of latitude is approximately 69

miles (111 km) apart.

5. The earth is not a perfect sphere but an oblate ellipsoid (slightly egg-shaped), causing a variation in distance as you approach the poles.

B. Longitude1. Vertical lines converging at the north and

south poles called meridians.

2. 0° is the Prime Meridian running through

Greenwich, England- an imaginary line

dividing our planet into the eastern and

western hemispheres.

3. Meridians run 180°east and 180°

west ; meet in the Pacific Ocean.

4. Each degree is 69 miles (111 km) apart.

 5. In 1884 during a convention held at the British Royal Observatory in Greenwich, England, the Prime Meridian was established as the starting point for measuring degrees longitude worldwide.

6.The International Date Line located on the other side of the world is located in the middle of the Pacific Ocean and is still longitude.

Photo by Matt Rosenberg

III. Divisions of the EarthA. Hemispheres

B. Additional Divisions

C. Precise Locations Using +/-

IV. How GPS Works…A. GPS devices functions as receivers.

B. Receive radio wave frequency broadcast from orbiting satellites send to ground stations.

C. 24 satellites function

worldwide all the time,

12 in each hemisphere.

D. When you turn on a GPSD. When you turn on a GPS unit, it locates the four unit, it locates the four closet satellites. closet satellites.E. Triangulation from towers E. Triangulation from towers can identify your location. can identify your location.

V. Reading the CoordinatesA. When reading the coordinates, they are read in

the following sequence:

Degrees, Minutes, Seconds, then

Direction.

B. 1 degree subdivided into 60 minutes

C. 1 minute subdivided into 60 seconds

D. Latitude is read before longitude.

E. Reading Practice

33 06’ 30”N, 96 39’ 27”W⁰ ⁰ Read as 33 degrees, 6 minutes

and 30 seconds of Latitude N of

the equator and 96 degrees,

39 minutes 27 seconds of

Longitude W of the Prime Meridian

VI. Display methods/same coordinates A. 33 06’30”N -96 39’27”W ⁰ ⁰ B. 33 06’30”N, 96 39’27”W ⁰ ⁰ C. 33 06’30”N/96 39’27”W ⁰ ⁰

VII. Find me if you can!!!!!a.Using a program of your choice locate the following coordinates and write them below b. Cowboy stadium c. American Airline Centerd. McKinney Court Housee. Eagle Stadiumf.Starbucks: Bethany and 75g.http://blip.tv/gatm/longitude-and-latitude-song-563068