History of Navigation Some of this might seem familiar

The Tools of Navigation The Stick Chart The Kamal The Compass The Cross Staff The Astrolabe The Mariners Quadrant The Sextant The Chronmeter

A _____________ _______is a sophisticated navigation aid based on knowledge the directions of approaching swells as well as wave refraction. Polynesians also used the stars to explore Micronesia in their double-hulled canoes.

The Arab ______ transom Knotted String Sailors would line up Polaris (The North Star) at their home port and tie a knot in the string. They would use that to “know” they are sailing along the right latitude.

The Compass An early form of the compass was invented in China in the 11th century. The familiar mariner's compass was invented in Europe around ______.

A compass determines position in response to the Earth’s magnetic field - NOT geographic or true north. Early Navigators unaware of this thought them to be inaccurate and only useful when the sun was down. However, sometimes magnetic north and true north are aligned in the same places on earth. This common area is called the __________.

When magnetic and true north line what is that common area called? 1.The Commons 2.The Agonic Line 3.The Agnostic Line 4.True Mag. North

The Cross Staff The _______ is moved up the stick marking Polaris (The north Star) to determine latitude. “Shooting the Stars” Transom

Astrolabe The Mariner's Astrolabe was used to determine the latitude of a ship at sea by measuring the noon altitude of the Sun or the meridian altitude of a star of known declination. The North Star (Polaris) Angle of the Star = Ships Latitude

If your Astrolabe told you that the angle of declination between the horizon and the north star was 39 degrees what is your latitude? 1.39 degrees south 2.39 degrees north 3.51 degrees south 4.Cannot be determined

MAPS were New Technology They weren’t always accurate. Ask Columbus

Mariners __________ The scale spans 90 degrees and is divided into whole degrees. A plumb bob establishes a vertical line of reference. Another way to measure the angle of a known star to determine latitude. Our Next Lab: Making a Quadrant

The Sextant A more accurate device to measure star (declination) to determine latitude. Notice the double mirrors and one with only half a mirror. You can align the star right along the horizon without tilting the device

A Marine Quadrant uses mirrors to determine declination. 1.True 2.False

Longitude remained a mystery until ____ ________ found a way to calculate it. He received a prize of £20,000 of money from the Royal Committee of Britain for developing the chronometer. Longitude lines run north to south and are used to measure east or west of the Prime Meridian. The chronometer is not much more than a very accurate timepiece which keeps Greenwich England time or GMT (Greenwich Mean Time) The Chronometer

Longitude is based on comparing local apparent noon - when the sun is highest in the sky - to the GMT and using the equation of time to convert to Greenwich apparent time. 360 degrees/24 hours in a day = 15 degrees/hour 60 minutes divided by 15 degrees= 4 minutes per degree

To calculate longitude: (a) Find the amount of time elapsed between local time and Greenwich time. (b) Convert the hours only to minutes by multiplying by 60, then add in the remaining minutes. (c) Divide the number of minutes by 4 to get an answer in degrees. (d) If the time at your location is earlier than GMT, then you are in the Eastern hemisphere; if it is later, then you are in the Western hemisphere

Captain James Cook Tested the ___________ on his second voyage in 1772 Made careful observations of Longitude (EW) Determined Harrison’s device works

Which navigation tool was used by the Polynesians ? 1.The Compass 2.The Stick Chart 3.The Astrolabe 4.The Chronometer

What is the name of this device? 1.Sextant 2.Compass 3.Cross Staff 4.Marine Quadrant

An early form of the compass was invented in the 11 th Century in which country? 1.China 2.Arabia 3.Europe 4.Portugal

Which one does NOT measure declination? 1.The Arab Kamal 2.The Sextant 3.The Compass 4.The Cross Staff

The term “shooting the stars” comes from the use of the …. 1.Compass 2.Astrolabe 3.The Kamal 4.The Cross Staff

Who invented the Chronometer? 1.John Harrison 2.Harrison Ford 3.James Cook 4.Magellan

What is the name of this device 1.The Stick Chart 2.The Arab Kamal 3.The Transom 4.The Sextant

The chronometer keeps track of time in ….. 1.Greenwich, Connecticut. 2.Greenwich Village 3.Greenwich, England 4.Paris, France

Global Positioning Systems (GPS) a PRECISE global positioning system developed and maintained by the Department of Defense consists of 24 satellites Available to the general public in the 1990’s

Latitude and Longitude Piloting or navigating uses coordinate lines called latitude and longitude on nautical maps called charts.

Latitude Geographers divided the Earth into two hemispheres. The north and the south. They are divided by a horizontal imaginary line called the Equator. The Equator is 0 o latitude.

Latitude is given first in degrees north or south of the equator; 3 digit number ex: 045N Latitude lines are parallel and run east to west.

They are equally spaced but not the same length; and can be used to measure distance north or south of the equator. One degree of latitude = 60 nautical mile. Degrees are divided into minutes: 1 minute of latitude = 1 nautical mile

Latitude The horizontal lines on the map are lines of latitude or parallels. They are parallel to the Equator. Latitude lines are given in degrees north or south of the Equator. Everything north of the Equator is in the Northern Hemisphere. Everything south of the Equator is in the Southern Hemisphere.

Latitude Where does that put us?

Latitude Two important parallels are 23 ½ o N which is the Tropic of _______ and 23 ½ o S which is the Tropic of _________. Other important lines of latitude are the _________Circle at 66 ½ o N and the _________ Circle at 66 ½ o S.

1 degree and 3 minutes equals 1.13 Nautical Miles 2.63 Nautical Miles 3.57 Nautical Miles 4.3 Nautical Miles

The correct way to write 41 degrees north latitude would be N 3.041N 4.041

0 Latitude is known as 1. Tropic of Cancer 2.Tropic of Capricorn 3.Equator 4.Prime Meridian

In the Northern Hemisphere, latitude can be determined by measuring the altitude or angle of Polaris, the North Star. If the star is 30 degrees above the horizon, the latitude is 30 o. Latitude may also be calculated by measuring the angle of the sun’s shadow at noon IF you have the declination. Latitude = 90 o - sun’s altitude + declination* *At the solstices, the declination is o in June and on December 21 it is o. At the equinox on March 21 and September 23, the declination is 0 o.

Longitude The vertical lines on the map are longitude lines or meridians. They are given in degrees east or west of the Prime Meridian. The Prime Meridian is 0 o It is called the prime because it is the primary meridian that others are based on. It is called meridian because it means midday. When the sun crosses any meridian it is noon or midday at that spot.

Longitude At 180 o it is exactly opposite the Prime Meridian and is called the ____________________. When you cross the International Date Line you move forward or backward one day. The International Date Line is in the Pacific. Moving toward California you gain a day, moving toward China you to backward one day.

Longitude Everything west of the Prime Meridian is in the Western Hemisphere. Everything east of the Prime Meridian is in the Eastern Hemisphere.

Longitude Where does that put us? PRIME MERIDIAN

180 degrees longitude is also known as 1.The Prime Meridian 2.The international dateline 3.The Equator 4.The Tropic of Capricorn

0 degrees longitude is known as 1.Prime Meridian 2.The Equator 3.The international Dateline 4.The Tropic of Cancer

Longitude divides the world into two hemispheres, they are: 1.Eastern and Southern 2.Western and Northern 3.Eastern and Western 4.Northern and Southern

In your next lab you will make a 1.Sextant 2.Astrolabe 3.Marine Quadrant 4.Chronometer