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. Longitude
1. 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 Earth
A. 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 GPS
unit, it locates the four
closet satellites.
E. Triangulation from towers
can identify your location.
V. Reading the Coordinates
A. 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
33⁰ 06’ 30”N, 96⁰ 39’ 27”W
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. 33⁰06’30”N -96⁰39’27”W
B. 33⁰06’30”N, 96⁰39’27”W
C. 33⁰06’30”N/96⁰39’27”W
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 Center
d. McKinney Court House
e. Eagle Stadium
f. Starbucks: Bethany and 75
g.
http://blip.tv/gatm/longitude-and-latitude-song-563068