Navigation

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Navigation
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SAD JOKE

• Dead ahead, through the pitch-black night, the
  captain sees a light on a collision course with
  his ship. He sends a signal "Change your course
  ten degrees east."    "Change yours ten degrees
  west," comes the reply.The captain responds,
  "I'm a United States Navy captain! Change your
  course, sir!"    "I'm a seaman second class,"
  the next message reads. "Change your course,
  sir."The captain is furious. "I'm a battleship!
  I'm not changing course!"    "I'm a lighthouse.
  Your call."

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How do we know where we are?
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You are here. Huh?
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• When people first started going out in boats they
  tended to stay close to shore so they could use
  landmarks to guide them.

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• As people ventured further (the Hawaiians 3000BC
  could travel over 1000km between islands) they
  needed to find other landmarks so they turned to
  the stars.

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Celestial navigation

• The pattern of stars and planets seen from Earth
  are constant in space.
• The celestial sphere.
• It is useful to be able to precisely specify
  positions on the celestial sphere.

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• The North Celestial Pole is the point on the
  celestial sphere directly above the Earth's North
  Pole.Similarly, the South Celestial Pole is
  directly above the Earth's South Pole.
• The star Polaris, in the constellation Ursa
  Minor, is located very close to the North
  Celestial Pole.Polaris is therefore also called
  the North Star.

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Tools of the trade

• Sexton measures the angle between celestial
  bodies and the Earth to determine position.
• Compass Point to magnetic North, so you can
  follow a course by knowing our position in
  relation to North.
• Loran C radio transmissions from set positions
  on the surface of the Earth, that triangulate to
  give you a position.
• GPS is a worldwide radio-navigation system
  formed from a constellation of 24 satellites and
  their ground stations.

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Sexton

• a device that measures the angle between two
  objects. It uses the position of stars to find
  latitude longitude.

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Compass
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Loran C

• LORAN-C was originally developed to provide
  radio-navigation service for U.S. coastal waters
  and later all of the continental U.S.
• Twenty-four U.S. LORAN-C stations work in
  partnership with Canadian and Russian stations to
  provide coverage in Canadian waters and in the
  Bering Sea.
• LORAN-C provides better than 0.25 nautical mile
  absolute accuracy.
• Loran-C is a low frequency/long wave electronic
  position fixing system using radio signals
  transmissions _at_ 100 KHz from 3 or more
  transmitters, linked in a chain. It gives a
  latitude and longitude readout position to
  marine, aero and land receivers.

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The Global Positioning System (GPS)

• The GPS is a worldwide radio-navigation system
  formed from a constellation of 24 satellites and
  their ground stations.
• GPS uses these "man-made stars" as reference
  points to calculate positions accurate to a
  matter of meters (or better than a centimeter in
  advanced models)!
• GPS receivers are becoming very economical, which
  makes the technology accessible to virtually
  everyone.
• These days GPS is finding its way into cars,
  boats, planes, construction equipment, movie
  making gear, farm machinery, balloons, and even
  laptop computers.

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What happens when you are not a good navigator!!!