Navigation

Question 1

What is navigation based upon?

Answer 1

A coordinate system or grid system of imaginary lines on Earth’s surface

These lines coincide with the time of day and the position of the North Star or Polaris in the Northern Hemisphere

Question 2

Units of Time

Answer 2

Day-Based on motions of Earth (rotation)

24 hours to rotate/360 degrees

15 degrees per hour

Month-Based on motions of the moon around the Earth

Year-Based on motions on the Earth (revolution) around the sun

Noon-Time when the sun reaches its zenith (or highest point overhead)

Question 3

GMT

Answer 3

Greenwich Mean Time

Time on the prime meridian (0 degrees) in Greenwich England

Question 4

Local clock Time

Answer 4

Time where you are

Question 5

Traveling and Time

West and East

Answer 5

West of the prime meridian is earlier

East is later

Question 6

Terrestrial Coordinate Systems: Lattitude

Answer 6

A measure of the angular distance North or South of the equator

0-90 degrees

Lines are horizontal or run parallel to the equator

Never meet

Question 7

Terrestrial Coordinate Systems: Longitude

Answer 7

Lines that measure the angular distance East or West of the Prime Meridian

0-180 degrees

Also called meridians

Are vertical

Meet at the poles

Question 8

To find the latitude:

Answer 8

If you know the altitude of the North Star or Polaris you can find your latitude

The altitude of Polaris is equal to the latitude of observer

Question 9

To find longitude:

Answer 9

Must know your local time and the time on the Prime Meridian and if you are East or West of the Prime Meridian

Determine time difference

Multiply difference by 15 degrees

Question 10

What is navigation?

Answer 10

The science of locating a position on Earth