# Coordinate System YouTube Lecture Handouts

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## Directions, Coordinate System & Time Zones

Agenda

• Understanding directions
• Coordinate system and degree
• Latitude and Longitude
• Time and Date Delineation

## Direction on a Map

• Why draw maps with north at the top?
• Standard convention.
• Compasses are made to measure to the magnetic north pole of the Earth.

## Finding the North?

• Left hand to west
• Right hand to east
• Face towards north

## North on the Map

• Magnetic north is measured by a compass.
• Grid north follows the grid lines of the coordinate system the map is made on.
• True north corresponds to the Earth՚s axis, the North Pole.

## Magnetic Declination

• Difference or angle between magnetic north and true north
• Topographic map depicts difference

## Measure Direction on a Map

• Use protractor or compass to measure degrees or angle from north line
• Both measure use circle of 360 degrees

## Map Grid

• Imaginary lines crossing the globe
• Meridian lines or longitude are drawn north-south
• Parallel lines or latitudes are drawn east-west
• Coordinate point is intersection of latitude and longitude

## Coordinate Systems

Two common coordinate systems are:

• Geographic coordinate system
• Universal Transverse Mercator (UTM)

## Geographic Coordinate System

• Latitude lines run east-west and are parallel.
• Longitude lines run north-south & are called meridians.
• Lines are numbered in degrees, minutes and seconds similar to a clock.
• Degrees is used as measurement tool because angles are always measured in degrees.

## Understanding Terms

• Each degree is divided into 60 minutes
• Each minute is divided into 60 seconds
• Holds true for both latitude and longitude
• Latitude: Distance from equator along Y axis
• Longitude: Distance from prime meridian along X axis – total 360 meridians (180 east and 180 west of prime meridian)

## Universal Transverse Mercator (UTM)

• UTM lines are straight on global map
• UTM is a type of projection, calculated to make a flat map of the round Earth.
• UTM zones are numbered east to west and lettered north to south.
• Each zone is equivalent to 6o and is measured in meters.

## Problem 2: Basics of Time

• Problem: If it is noon where you are, would it be before or after noon for someone that is east of you?
• After noon
• Recall, the sun rises in the east and sets in the west
• As you look down from the north pole, the earth would rotate counterclockwise
• If the sun is just beginning to rise in California, then the sun would be near noon in New York, so …
• As you travel east, time becomes later

## Time Zone

• Earth is divided into 24 time zones!
• because the Earth Rotates
• 1 Time zone for every 150 of Longitude
• The Earth Spins 360 0 in 24 hours
• hours
• Or longitude is 4 minutes
• We measure from Prime Meridian in Greenwich England
• Every to the East =+ 1 Hour
• Every to the West =- 1 Hour

## Greenwich, England is Initiation Point for Time Zones

• World rotates west to east (counterclockwise) , so time zones to the east are ahead of the those time zones to the west

## Problem 3 – Time Zone

How many hours difference is there between Tokyo?

• So the difference is
• Since one hour is 150 longitude
• So it is hours.
• Now Tokyo is east of Rome, so it is 8 hours later in Tokyo.

## International Date Line

• Located in mid-Pacific Ocean near 180° longitude.
• Crossing IDL from east to west, it՚s the next day (+ 1 day)
• Crossing IDL from west to east, it՚s the previous day (-1 day)

## Problem 4 - IDL

• It is 9 AM Saturday in California what time is it in Australia ?
• So, it is per hour = 7 hours
• So total time difference is 7 hours, since travelling east to west, time becomes earlier it is 7 hours before, i.e.. , 2 AM
• Also you are crossing IDT east to west, so it becomes next day, therefore time in Australia is 2 AM Sunday

## Daylight Savings Time

• Used mainly in USA to add an “extra” hour of daylight in the afternoon during spring/summer
• “Spring forward and Fall back”

## Problem 5 - Sunrise/Sunset Time Corrections

• If sunset in Winnipeg what is the time for sunset in Manitoba
• Difference is
• longitude is 4 minutes
• longitude is minutes
• So, it is 32 minutes late, i.e.. , 5: 25 PM + 32 minutes = 5: 57 PM

## Jet Lag

• Medical phenomena that occurs due to crossing the various time zones
• Characterized by extreme fatigue, disorientation and loss of appetite.
• Sleep is seen as one of the best cures for jet lag, as is exposure to sunlight.
• It is considered that it takes 1 day per time zone to recover from jet lag.

Manishika