Tue, 25 Jan

# Latitude Longitude

##### Latitude
• Horizontal mapping lines on Earth are lines of latitude (AKA parallels).
• Are the temperature coordinates of Earth.
• The equator is the starting point for measuring latitude.
• One degree of latitude is 60 nautical miles, 69 statute miles or 111 km.
• One minute of latitude is 1 nautical mile, 1.15 statute miles, or 1.85 km.
• Angles can range UP to +90 degrees (or 90 degrees north), and DOWN to -90 degrees (or 90 degrees south).
• Equator {0° parallel} itself is largest parallel and only circle of latitude which also is a great circle.
##### Latitude
• Vertical mapping lines on Earth are lines of longitude (AKA meridians).
• Are the time coordinates of Earth.
• The Prime Meridian (Universal vertical line at British Royal Observatory in Greenwich England) is starting point to measure how far a location is east or west.
• Lines of longitude or meridians, run between the North and South Poles, with half-circles.
• Measure distance east or west of prime meridian.
• Are the farthest apart at the Equator and meet at the poles.
• Cross the Equator at right angles.
• Are equal in length (Lines of Longitude are all just as LONG as one another).
• Angles can range UP to +180 degrees (or 180 degrees east) and DOWN to -180 degrees (or 180 degrees west).
• The +180 and -180 degree longitude meridians coincide directly opposite the prime meridian.
• The distance between two meridians is farthest at the equator and it decreases as we move towards poles and becomes zero at poles.
##### Key Points
• A globe has two fixed points - the North Pole and the South Pole.
• Equator lies exactly halfway between two poles.
• Every location on earth has a global address.
• The Prime Meridian divides the globe into Eastern and Western hemispheres, just as the equator divides the globe into Northern and Southern hemispheres.
• The Prime Meridian is at 0 degrees longitude, just as the equator is at 0 degrees latitude.
• A global address is given as two numbers called coordinates
• Local Time: It is the time at a certain location. Local time of any place is 12 noon when the sun is exactly overhead. It will vary from the Greenwich time at the rate of four minutes for each degree of longitude.
• Standard Time: It is the uniform time fixed by each country. It is fixed in relation to mean time of a certain meridian which generally passes through it.
• Greenwich Mean Time: The time at 0° longitude is called Greenwich Mean Time. It is based on local time of the meridian passing through Greenwich near London.
• Indian Standard Time: It is fixed on the mean of 821/2°E Meridian, a place near Allahabad. It is five and half hours ahead of Greenwich Mean Time.
• International Date Line: It is an imaginary line of demarcation on the surface of Earth that runs from the North Pole to the South Pole and demarcates the change of one calendar day to the next.