Abstract: |
The Earth is a sphere. Like any sphere, the Earth can be modelled using a series of horizontal and vertical circles. Latitude and longitude lines form a global grid which is used as an international referencing system. Latitude and longitude perform the same function as the grid reference numbers and letters in this directory. The difference is, the system is global. After much argument, world leaders agreed to define zero longitude as the line which passes through Greenwich in England. Now, with Global Positioning Systems, we can locate a place or a person fast and precisely. |