GPS is a system of 30+ navigation satellites circling Earth. We know where they are because they constantly send out signals. A GPS receiver in your phone listens for these signals. Once the receiver calculates its distance from four or more GPS satellites, it can figure out where you are.
Earth is surrounded by navigation satellites. Credit: NOAA.
Humans have looked to the skies to find their way since ancient times. Ancient sailors used the constellations in the night sky to figure out where they were and where they were going.
Today, all we need is a simple hand-held GPS (short for Global Positioning System) receiver to figure out exactly where we are anywhere in the world. But we still need objects high in the sky to figure out where we are and how we get to other places.
Instead of stars, we use satellites. Over 30 navigation satellites are zipping around high above Earth. These satellites can tell us exactly where we are.
What is GPS?
The Global Positioning System (GPS) is made up of satellites, ground stations, and receivers.
GPS is a system. It’s made up of three parts: satellites, ground stations, and receivers.
Satellites act like the stars in constellations—we know where they are supposed to be at any given time.
The ground stations use radar to make sure they are actually where we think they are.
A receiver, like you might find in your phone or in your parents car, is constantly listening for a signal from these satellites. The receiver figures out how far away they are from some of them.
Once the receiver calculates its distance from four or more satellites, it knows exactly where you are. Presto! From miles up in space your location on the ground can be determined with incredible precision! They can usually determine where you are within a few yards of your actual location. More high-tech receivers, though, can figure out where you are to within a few inches!
The ancient sailors of history would be flabbergasted by the speed and ease of pinpointing your location today.
GPS in everyday life
There’s a whole lot of important things GPS is used for—but perhaps nothing is more important than finding the quickest slice of pizza! Check out our fun Space Place in a Snap animation “GPS and the Quest for Pizza” to learn more about how GPS works.
GPS is a system of 30+ navigation satellites circling Earth. We know where they are because they constantly send out signals. A GPS receiver in your phone listens for these signals. Once the receiver calculates its distance from four or more GPS satellites
GPS satellites
GPS satellite blocks are the various production generations of the Global Positioning System (GPS) used for satellite navigation. The first satellite in the system, Navstar 1, was launched on 22 February 1978.
https://en.wikipedia.org › wiki › GPS_satellite_blocks
There are over 30 satellites used for GPS, orbiting over 16,000 miles (26,000km) above the Earth! Your phone just needs to figure out how far away you are from some of them. If your phone knows how far away it is from four satellites, then there is only one place on Earth you can be!
GPS-based navigation uses one-way signals from GPS satellites to determine the spacecraft's trajectory through its on-board instruments and data processing.
The GPS receiver in your mobile device compares the time signals it receives from the satellites with its internal clock. Knowing the speed of light and when the signals were sent and received, your device can calculate your distance from each satellite, and thereby home in on your longitude, latitude and altitude.
The GPS Master Control Station (MCS), operated by Delta 8 at Schriever AFB, is responsible for monitoring and controlling the GPS satellite constellation. The GPS-dedicated ground system consists of six U.S. Space Force dedicated monitor stations (MS) and four ground antennas (GA) located around the world.
GPS is a system of 30+ navigation satellites circling Earth. We know where they are because they constantly send out signals. A GPS receiver in your phone listens for these signals. Once the receiver calculates its distance from four or more GPS satellites, it can figure out where you are.
GPS works on the “Trilateration mathematical principle”. This principle uses distances to points at known coordinates to locate an object's position. Trilateration needs 3 ranges to 3 known points whereas a GPS needs 4 pseudo-ranges to 4 satellites.
HOW GPS WORKS. GPS satellites circle the Earth twice a day in a precise orbit. Each satellite transmits a unique signal and orbital parameters that allow GPS devices to decode and compute the precise location of the satellite. GPS receivers use this information and trilateration to calculate a user's exact location.
These satellites are constantly sending out radio signals. GPS receivers are programmed to receive information about where each satellite is at any given moment. A GPS receiver determines its own location by measuring the time it takes for a signal to arrive at its location from at least four satellites.
National Aeronautics and Space Administration NASA What is GPS? The Global Positioning System (GPS) is a space-based radionavigation system, owned by the U.S. Government and operated by the United States Air Force (USAF).
The Global Positioning System (GPS) is a U.S.-owned utility that provides users with positioning, navigation, and timing (PNT) services. This system consists of three segments: the space segment, the control segment, and the user segment.
GPS satellites broadcast their signals in space with a certain accuracy, but what you receive depends on additional factors, including satellite geometry, signal blockage, atmospheric conditions, and receiver design features/quality. For example, GPS-enabled smartphones are typically accurate to within a 4.9 m (16 ft.)
Using the Global Positioning System (GPS), every point on Earth can be given its own unique address—its latitude, longitude, and height. The U.S. Department of Defense developed GPS satellites as a strategic system in 1978.
Currently 31 GPS satellites orbit the Earth at an altitude of approximately 11,000 miles providing users with accurate information on position, velocity, and time anywhere in the world and in all weather conditions. GPS is operated and maintained by the Department of Defense (DoD).
As demands increased, GPS grew from 24 satellites to 37
If GPS went away, the impact would be immediate and drastic. Countless commercial flights would be delayed. There would be increased costs for most goods and services. There would be delays in accessing your funds from banks and retirement accounts.
How GPS Tracking Works. The GPS tracking device is installed into a vehicle (or piece of equipment or asset) to gather real-time information including speed, idle time, diagnostics, etc. It uses Global Positioning Systems (GPS satellites) to know the vehicle or equipment's location on Earth at all times.
Earth scientists also use GPS technology to conduct a wide range of research. By installing high accuracy GPS receivers on physical features such as glaciers or landslips, scientists can observe and study both the speed and direction of movement, helping them to understand how landscapes change over time.
Astronomy: both positional and clock synchronization data is used in astrometry and celestial mechanics and precise orbit determination. GPS is also used in both amateur astronomy with small telescopes as well as by professional observatories for finding extrasolar planets.
Introduction: My name is Arielle Torp, I am a comfortable, kind, zealous, lovely, jolly, colorful, adventurous person who loves writing and wants to share my knowledge and understanding with you.
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