Learn Latitude and Longitude A key geographical question throughout the human experience has been, "Where am I?" In classical Greece and China, attempts were made to create logical grid systems of the world to answer this question. The ancient Greek geographer Ptolemy created a grid system and listed the coordinates for places throughout the known world in his book Geography. But it wasn't until the middle ages that the latitude and longitude system was developed and implemented. Latitude When looking at a map, latitude lines run horizontally. Longitude The vertical longitude lines are also known as meridians. How Latitude and Longitude Work Together To precisely locate points on the earth's surface, degrees longitude and latitude have been divided into minutes (') and seconds ("). To locate the latitude and longitude of a specific place on earth, see my Locate Places Worldwide collection of resources.
USNO NAVSTAR Global Positioning System The following Global Positioning System (GPS) information is obtained from the 1994 Federal Radionavigation Plan (FRP), prepared jointly by the Department of Defense (DoD) and the Department of Transportation (DoT) and other sources such as conferences, meetings and seminars. The GPS is a DoD developed, worldwide, satellite-based radionavigation system that will be the DoD's primary radionavigation system well into the next century. The constellation consists of 24 operational satellites. The U.S. Air Force Space Command (AFSC) formally declared the GPS satellite constellation as having met the requirement for Full Operational Capability (FOC) as of April 27, 1995. Requirements include 24 operational satellites (Block II/IIA) functioning in their assigned orbits and successful testing completed for operational military functionality. GPS provides two levels of service, Standard Positioning Service and the Precise Positioning Service . US Naval Observatory Home Page What Time Is It?
Satellite Learning Center How Do Satellites Work? A satellite works by receiving radio signals sent from the Earth and resending the radio signals back down to the Earth. In a simple system, a signal is reflected, or "bounced," off the satellite. For example, it is possible to bounce a signal off the surface of the Moon back down to Earth. Unlike a passive satellite such as the moon or the early ECHO satellite, a modern communications satellite receives the radio signal and sends it back down to Earth stronger than it was received. People communicate to a satellite using an antenna on the ground, which called an "earth station" in technical terms. The satellite receives these signals, makes them stronger, and then re-transmits them back down to the Earth. Sometimes the uplink and downlink earth stations perform various specialized functions. The area that can be served by a satellite is determined by the "footprint" of the antennas on the satellite.
How GPS Receivers Work" Our ancestors had to go to pretty extreme measures to keep from getting lost. They erected monumental landmarks, laboriously drafted detailed maps and learned to read the stars in the night sky. Things are much, much easier today. In this article, we'll find out how these handy guides pull off this amazing trick. When people talk about "a GPS," they usually mean a GPS receiver. Each of these 3,000- to 4,000-pound solar-powered satellites circles the globe at about 12,000 miles (19,300 km), making two complete rotations every day. A GPS receiver's job is to locate four or more of these satellites, figure out the distance to each, and use this information to deduce its own location.
Satellites "Man must rise above the Earth -- to the top of the atmosphere and beyond -- for only thus will he fully understand the world in which he lives." Socrates made this observation centuries before humans successfully placed an object in Earth's orbit. And yet the Greek philosopher seemed to grasp how valuable a view from space might be, even if he didn't know how to achieve it. Those notions -- about how to get an object "to the top of the atmosphere and beyond" -- would have to wait until Isaac Newton, who published his now-famous cannonball thought experiment in 1729. His thinking went like this: Imagine you place a cannon atop a mountain and fire it horizontally. The cannonball will travel parallel to Earth's surface for a little while but will eventually succumb to gravity and fall to the ground. In October 1957, the Soviets finally proved Newton correct when they launched Sputnik 1 -- the first artificial satellite to orbit Earth.
GPS User Support Civilian User Support — Non-Aviation The U.S. Coast Guard Navigation Center (NAVCEN) is the primary point of contact in the government for providing operational GPS user support to the civilian community. The following links lead to pages on the NAVCEN website. If you suspect a GPS disruption due to illegal signal jamming (Learn more), please call the FCC Jammer Tip Line immediately at 1-855-55-NOJAM, then submit an outage report to NAVCEN. For help with wrong addresses, bad directions, and other map-related errors in GPS devices, please visit our page on Address, Route, & Map Problems. Civilian User Support — Aviation Civil aviation users should contact the Federal Aviation Administration (FAA) for GPS user support within the United States. Military User Support The GPS Operations Center (GPSOC) at Schriever Air Force Base, Colorado, is the focal point in the Department of Defense (DOD) for operational issues and questions concerning military use of GPS. The GPSOC is responsible for:
How Do Satellites Work Title Page Each GPS satellite sends out two low power radio signals which are designated L1 and L2. GPS used by civilians use the L1 signals, which have a frequency of around 1575.42 MHz in the UHF band. Signals “travel by line of sight,” ( which means that though they can pass through clouds, glass, and plastic, they are unable to make it through most other solid objects. Signals are given a pseudorandom code which serves as an ID used to identify which satellite the information is coming from. Each satellite continuously sends out what is known as ephemeris data. Geographic coordinate system A graticule on a sphere or an ellipsoid. The lines from pole to pole are lines of constant longitude, or meridians. The circles parallel to the equator are lines of constant latitude, or parallels. Latitude and Longitude of the Earth A geographic coordinate system is a coordinate system that enables every location on the Earth to be specified by a set of numbers or letters. Geographic latitude and longitude[edit] A line, which was intended to pass, through the Royal Observatory, Greenwich (a suburb of London, UK) was chosen as the international zero-longitude reference line, the Prime Meridian. In 1884 the United States hosted the International Meridian Conference and twenty-five nations attended. The combination of these two components specifies the position of any location on the planet, but does not consider altitude nor depth. UTM and UPS systems[edit] Stereographic coordinate system[edit] During medieval times, the stereographic coordinate system was used for navigation purposes. is
Lat Long Map of Australia The Commonwealth of Australia is located on the geographic coordinates of 25.0000° S latitude and 135.0000° E longitude in Australia. Australia, the smallest among the continents of the world, is located in between 27°00' South Latitude and 133°00' East Longitude. Some of Australia 's major cities are located in slightly different latitude and longitudinal areas. Australia 's latitude and longitude has given it a particular type of climate.
Title Page The Global Positioning System, also known as the GPS, is made up of a network of around twenty-four satellites sent into orbit by the Department of Defense of the US. It is a navigation system which was initially meant to be used for US military purposes. However, in the 1980’s, civilians were allowed access to the system, too, by the US government. The GPS is made up of 24 satellites that orbit the earth.
Hawaii tiger shark migration in fall coincides with rise in bites Traditional Hawaiian stories warn about an increased danger of shark bites in the fall, from September to November. A recent study shows that there could be something behind this folk wisdom: During this time, an increased number of tiger sharks make their way to the islands, likely to give birth. "Both the timing of this migration and tiger shark pupping season coincide with Hawaiian oral traditions suggesting that late summer and fall, when the wiliwili tree blooms, are a period of increased risk of shark bites," said study co-author Carl Meyer, a researcher at the University of Hawaii, in a statement. But Meyer and lead author Yannis Papastamatiou, a researcher at the Florida Museum of Natural History, said that people shouldn't jump to the conclusion that this migration is directly related to recent shark bites near the islands. The study that found the potential link involved tagging tiger sharks over a seven-year period, and included more than 100 animals, most of them female.
What is Migration? In ecology and animal behaviour, Migration, Migratory behavior, or Migratory may refer to: Other scientific uses[edit] Information technology[edit] Data migration, the process of transferring data between storage types, formats, or computer systemsSystem migration, the tasks involved when moving data and applications from current hardware to new hardwareSoftware migration, refers to the conversion, rewriting or porting of a legacy system to a modern computer systems Arts and entertainment[edit] Other uses[edit] Piercing migration, in body modification, a process that occurs when a body piercing moves from its initial location See also[edit]