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Navigational Elements

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					            Where am I?
• N39.797013 degrees, W84.126885 degrees
       Navigational Elements
Know the four elements of navigation.
  State how to determine position using latitude and
     longitude
  State how to determine direction using cardinal
     directions and compass rose degrees
  State how to determine distance both in nautical
     and statute miles
  State how to determine time based
    on distance and speed traveled
Points on a Map Assignment
• Lines of reference are necessary in order to locate
  specific points on the Earth.
                   Finding Your Position
•   Latitude is expressed as
    either north or south of the
    equator in degrees up to 90,
    and longitude is expressed
    as either east or west and is
    expressed in degrees up to
    180.
    – A degree (o) of arc may be
      subdivided into smaller
      units by dividing each
      degree into 60 minutes (’)
      of arc.
    – Each minute may be
      further subdivided into 60
      seconds (”) of arc.
    – Smaller areas can be
      located by going beyond
      degrees and minutes and
      using seconds.
                              Position
• Longitude
  •   The Greenwich Meridian is
      sometimes called the first
      or prime meridian,
      although it is actually the
      zero meridian.
      • Longitude is counted east and
        west from this meridian
        through 180o.
      • The Greenwich Meridian is
        the 0o longitude on one side
        of the Earth; and, after
        crossing the poles, it becomes
        the 180th meridian.
      • These designations define the
        Eastern and Western
        Hemispheres.
    What is the step by step procedure for finding
    the absolute location of a place on the earth?




Start with latitude: 1. Go to the Equator 2. Determine your direction
(north or south) 3. Determine the distance (in degrees) Then do the
longitude: 1. Go to the Prime Meridian 2. Determine your direction (east
or west) 3. Determine the distance (in degrees) Find the intersection of
these two lines for the absolute location.
         Where am I?
N39.797013 degrees, W84.126885 degrees
      Where am I?




N30 degrees W 60 degrees
POP QUIZ

5 QUESTIONS
Which letter is located at 50 degrees
   north and 120 degrees east?
 0 degrees latitude, 0 degrees longitude, the
  intersection of the Equator and the Prime
Meridian, would be located in which ocean?
What continent would you be on at
 10 degrees south and 70 degrees
              west?
An airplane crashes at 40 degrees north
and 60 degrees east. What letter would
 you travel to to hunt for survivors?
  You receive a radio SOS call that a boat is
 sinking at 20 degrees south and 100 degrees
east. What ocean would you travel to to try to
              rescue the people?
POP QUIZ REVIEW
Which letter is located at 50 degrees
   north and 120 degrees east?
 0 degrees latitude, 0 degrees longitude, the
  intersection of the Equator and the Prime
Meridian, would be located in which ocean?
What continent would you be on at
 10 degrees south and 70 degrees
              west?
An airplane crashes at 40 degrees north
and 60 degrees east. What letter would
 you travel to to hunt for survivors?
  You receive a radio SOS call that a boat is
 sinking at 20 degrees south and 100 degrees
east. What ocean would you travel to to try to
              rescue the people?
                         Direction
• Direction is the
  position of one
  point in space,
  relative to another,
  without reference
  to the distance
  between them.
• The points of a
  compass are not
  adequate for
  modern navigation.
  It has been
  replaced, for the
  most part, by a
  numerical system.
DIRECTION KNOCKOUT!!!
                Direction
• Since determination of direction is one of
  the most important parts of the navigator’s
  work, the various terms involved should be
  clearly understood.
  • Course – Where I want to go
  • Heading – Which way I am pointed when I
    travel
  • Track – Actual path I follow
                 Distance
• Measured by the length of a line joining two
  points. In navigation, the most common unit
  of measuring distance is the nautical mile.
  • The nautical mile is about 6,076 feet.
  • Equal to 1 minute of arc on a meridian, which
    is 1 minute of latitude.
  • To convert nautical miles to statute miles, the
    nautical mile figure can be multiplied by the
    factor 1.15.
  • To convert statute miles to nautical miles,
    multiply the statute miles by 0.87.
                    Time
• The Earth makes a complete rotation of
  360o during a 24 hour day.
• Zone Time
  • Before the establishment of zone time in 1883,
    every city and town had its own time.
  • Each time zone is 15o of longitude (1 hour of
    angular measure) in width, and the first zone
    centers on the prime meridian.
  • The United States has four standard time
    zones (in the contiguous states).
                   Time
• Greenwich Mean Time
  • The use of Greenwich Mean Time (GMT)
    avoids the necessity of considering time
    zones.
  • GMT is the time of day at any given moment
    at Greenwich, England.
                 Summary
1.   Earth’s Size and Shape
2.   Position
3.   Direction
4.   Distance
5.   Time

				
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