Navigation :: Geography History Navigation Essays

Navigation Early Explorers such(prenominal) as Christopher Columbus and Magellan relied on landmarks for early navigation, which could result in severe miscalculations. Later explorers discovered they could use the stars as their primary choice for navigation. As technology increased the compass and sextant were used in navigation purposes. The phonograph needle of a compass always pointed north, while the sextant used adjustable mirrors to dance step angles of the moon and stars. The sextant could further calculate latitude so a braid called the chronometer was later invented by John Harrison to image longitude. The sextant and chronometer were used together to compute measures of longitude and latitude. In the early 20th century m some(prenominal) radio-based navigation systems were developed. however these radio based systems were either accurate or covered a large area of quadrangle, but not both. Scientists then decided that the only way to cover the entire world was to put high relative frequency radio systems in space, hence the idea of GPS or global arrangement systems was born. GPS was funded and founded by the Department of Defense. The Departmemet of Defense also controls GPS. The first GPS satellite was launched in 1978. The first ten satellites were called block I satellites. From 1989 to 1993, 23 production satellites called banish II were launched. The last satellite was launched in 1994 completing the system. From this point on with a GPS receiver costing only a few 100 dollars you could constantly learn your location on the planet.GPS is the only system for sale today that will tell someone their exact line on Earth at any given time in any type of weather. There are 24 satellites in all, which orbit active 11,000 nautical miles above the earth. The satellites are monitored by ground stations rigid around the world and can transmit signals that can be spy by anyone with a GPS receiver. Using this receiver you ca n determine your position on Earth with great accuracy. GPS satellites consist of 3 segments space, control and user. The space segment consists of the 24 satellites in six orbital planes(four satellites in distributively plain). Each satellite repeats the same 12-hour orbit, but appears four minutes to begin with each day. Each satellite orbits at 55 degrees in respectfulness to the equatorial plane with a 12-hour period to orbit the earth.