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How does a GPS receiver calculate its distance from a satellite?
Wiki User
∙ 11y ago
Very easily. The GPS receiver measures how long it takes a certain radio signal to travel from the GPS satellite(s) to itself, and from that, the receiver calculates the distance. It can do that because it knows precisely how fast the radio signal travels.
If you have signals from at least 3 satellites, the process of trilateration (not triangulation) pinpoints the location where the 3 distances 'cross' each other. If you have 4 satellites 'locked in', then you will find out your altitude, too. (The process is not quite this simple, but to go on would be confusing.)
The hard part is measuring the precise time it takes for a certain radio signal to travel from the GPS satellite to your GPS receiver. Well, hard if you do it, but very easy when the GPS receiver does it!
First, each GPS satellite carries an on-board atomic clock. This clock is outrageously accurate, but even so, ground stations connected to the US Navy atomic clock system keep each satellite precisely at the correct time. Your GPS receiver has an on-board high-precision clock of its own.
Second, when your GPS receiver first makes contact with the constellation of GPS satellites, it is sent an 'almanac' that lists where each satellite is, what it's precise time is, and other goodies. After reading the almanac, the GPS receiver sets itself to the precisely same time as the satellite constellation.
Thirdly, when the GPS receiver gets a signal from the satellites, there is information in it that says precisely at what time the radio signal left each satellite, which is identical for all the satellites. Then your GPS receiver 'looks at its watch' and subtracts the 'sent' time from the 'received' time. The data in the almanac are updated by the satellite constellation every few hours so that your GPS receiver will always know where the satellites are and what their precise time is.
Go back to the beginning and reread what your GPS receiver can do once it knows the precise travel time of the radio signal.
Wiki User
∙ 11y ago
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What does a gps satelite do?
A GPS satellite emits a very precise and accurate time signal that the receiver can use to calculate it's distance from the satellite.
What is it necessary to observe a minimum of four gps satellites to define position?
The GPS receiver measures the distance from it to a GPS satellite. Then it measures the distance to another GPS satellite. The location is somewhere on a line made up of the millions of plaes that these two distances cross each other. A third satellite distance is required to find out where your GPS receiver is, somewhere on that line.This process is called "Trilateration" (Three distances). (Not triangulation).If you want to know how high you are above sea level, you need a distance from a fourth satellite.
What causes GPS interference?
GPS units calculate your position by measuring the distance to four satellites. Your GPS receiver does this by knowing the exact pattern that the satellite transmits, allowing you to know how long the signal took to arrive. Since the receiver knows exactly where the satellites are, it can figure out where you are. If the radio signal bounces from something like a mountain or a building, then it will take longer than expected for the signal from the satellite to reach your receiver. The receiver may calculate your position incorrectly.
How does a GPS receiver work?
A GPS (short for "Global Positioning System") is an electronic device that measures its distance to three or more satellites to determine its precise location. There are 24 such satellites in fixed orbits around the world. All of the satellites are perfectly synchronized, and send out digital radio transmissions broadcasting the current time. Your GPS receiver receives three or more of these signals, where the distance to the satellite will delay the signal just a tiny bit. The GPS receiver uses the relative delays to determine its precise location. GPS receivers are available from Garmin, Magellan, Tom Tom, and a number of other companies. Many newer cellphones also have a built-in GPS receiver.
Does GPS represent an invasion of your privacy?
No. It's just a radio receiver, listening for satellite signals.
What does a gps satelite do?
A GPS satellite emits a very precise and accurate time signal that the receiver can use to calculate it's distance from the satellite.
What is it necessary to observe a minimum of four gps satellites to define position?
The GPS receiver measures the distance from it to a GPS satellite. Then it measures the distance to another GPS satellite. The location is somewhere on a line made up of the millions of plaes that these two distances cross each other. A third satellite distance is required to find out where your GPS receiver is, somewhere on that line.This process is called "Trilateration" (Three distances). (Not triangulation).If you want to know how high you are above sea level, you need a distance from a fourth satellite.
How do GPS's work?
GPS works like a distance measuring device using a laser.... the only difference is it uses time intervals. GPS consist of some components such as the satellite receiver , atomic clocks, power supply and etc. Lets start from GPS satellite... in these satellites they have we so called the atomic clocks. These clocks gives time and being sent by the transmitter in the satellite in all direction and within this direction the GPS receiver we have onland or on seas can detect this and try to calculate at what time it received the signal. This calculation will give you the bearing(direction) and distance travelled by this signal, with 3 satellites it can give you the accurate position of your receiver by plotting these distances and directions(cross-bearings).
How do GPS WORK?
GPS works like a distance measuring device using a laser.... the only difference is it uses time intervals. GPS consist of some components such as the satellite receiver , atomic clocks, power supply and etc. Lets start from GPS satellite... in these satellites they have we so called the atomic clocks. These clocks gives time and being sent by the transmitter in the satellite in all direction and within this direction the GPS receiver we have onland or on seas can detect this and try to calculate at what time it received the signal. This calculation will give you the bearing(direction) and distance travelled by this signal, with 3 satellites it can give you the accurate position of your receiver by plotting these distances and directions(cross-bearings).
What causes GPS interference?
GPS units calculate your position by measuring the distance to four satellites. Your GPS receiver does this by knowing the exact pattern that the satellite transmits, allowing you to know how long the signal took to arrive. Since the receiver knows exactly where the satellites are, it can figure out where you are. If the radio signal bounces from something like a mountain or a building, then it will take longer than expected for the signal from the satellite to reach your receiver. The receiver may calculate your position incorrectly.
How does a GPS receiver work?
A GPS (short for "Global Positioning System") is an electronic device that measures its distance to three or more satellites to determine its precise location. There are 24 such satellites in fixed orbits around the world. All of the satellites are perfectly synchronized, and send out digital radio transmissions broadcasting the current time. Your GPS receiver receives three or more of these signals, where the distance to the satellite will delay the signal just a tiny bit. The GPS receiver uses the relative delays to determine its precise location. GPS receivers are available from Garmin, Magellan, Tom Tom, and a number of other companies. Many newer cellphones also have a built-in GPS receiver.
How does gps calculate its positinon?
by satellite.
What is pseudo range?
The pseud orange is a measure of the range, or distance between the GPS receiver and the GPS satellite, since there is accuracy errors in the time measured, the term pseudo-range are used rather than ranges for such distance.
How a GPS works?
How a GPS works is like a description or paragraph explaining this. But how does it work is a question asking for information. The principle behind GPS is the measurement of distance between the satellites and the receiver. The satellites tell us exactly where they are in their orbits by broadcasting data the receiver uses to compute their positions. It works something like this: If we know our exact distance from a satellite in space, we know we are somewhere on the surface of an imaginary sphere with a radius equal to the distance to the satellite radius. If we know our exact distance from two satellites, we know that we are located somewhere on the line where the two spheres intersect. And, if we take a third and a fourth measurement from two more satellites, we can find our location. The GPS receiver processes the satellite range measurements and produces its position.
If your GPS system is stolen out of your tractor can it be relocated when it is turned back on?
Unfortunately, a GPS is a receiver only. It locates its position on the surface of the earth by determining its distance from a series of satellites. It does not transmit any information back to the satellites, which would be necessary for a satellite to locate the GPS.
What is the function of the navigation satillite?
Satellite Navigation The U.S. govt launched satellites that triangulate any spot on the globe and give your location if you have the device that receives their signal. For further clarification, GPS receiver units time a signal sent from a satellite and through the use of extremely accurate clocks, calculate the time it took for the signal to reach the receiver from the satellite. Knowing the speed that these signals travel allows the receiver to calculate a distance from the satellite which results in a line of position (LOP). Obtaining a minimum of three of these LOPs allows the receiver to accurately determine the receiver's position on the face of the earth. Having a fourth LOP will also allow the determination of the elevation, or height, of the receiver.
Does GPS represent an invasion of your privacy?
No. It's just a radio receiver, listening for satellite signals.
