GPS What is it, what is it for and how does this geographic location system work?

0 17 11 minutes of reading

With the development of technology, many solutions have emerged for simplify people's daily life . That is why many terms have been adopted which cover a myriad of optimal utilities when commissioning a certain system. This is the case with geolocation system recognized which uses the acronym "GPS" .

In general, users rely on this system which, via their smartphone or their car , allows them to locate a specific point on a map and go anywhere, without even knowing the address. But, although this is a widely used technology at the moment, the truth is that beaucoup ne know always not how does GPS actually work .

Therefore, in order to understand what is GPS and what it is used for , we will detail this information of great interest below. Even, it is also worth know its origin and history , the aspects which intervene in its signal to offer precise results and even its scientific foundations . Which one you can meet here.

What is the GPS system and what is it used for in computers?

Being the acronym of "Global Positioning System" which in Spanish means "Global Positioning System" , GPS is defined as a satellite navigation system that allows determine the position of any object on Earth . Which consists of a navigation system that operates through a network , promising has at least 24 satellites and is located on the planet at an altitude of about 20 km.

For its part, in computer science, this global positioning technology has been induced in different devices and mobile phones , mainly. In this way, it allows to locate said equipment in case of theft, to run certain applications requiring this functionality, to maximize the functioning of the games, to reach a precise address when traveling by car, motorbike, bicycle or even on foot , etc.

In this sense, GPS has the ability to locate any person, vehicle or thing , regardless of the speed at which it is moving. In addition, it has the necessary characteristics to reveal data such as its height at any time and its specific point in the earth globe. While its precision goes up to a few centimeters and that is why it is so effective.

What are the characteristics of GPS and what can be done with it?

To find out more about the composition of the GPS, please specify what are its main characteristics . So, first of all, it should be noted that a GPS is composed of three elements which are : satellites orbiting the Earth, user-owned GPS receivers and ground monitoring and control stations. Thus, it is appreciated that the GPS is composed of three different components or sectors, such as: the space sector, user sector and land sector .

Then we specify what it is:

Space sector : It is made up of 24 satellites arranged in a total of six orbits (4 satellites in each of them). Which roam the planet at a height of 20 km and their speed of rotation, approximately, corresponds to one round the earth every 12 hours . They also follow a route with an inclination of 55 degrees from the celestial equator.
User sector : It consists of an antenna, an amplifier and a receiver . From these elements, the team chooses the satellites that can provide the information necessary to determine the relevant position and measure the time between transmissions.
Land sector : It consists of a control sector which is responsible for correct the signal acquired by the satellites and, in addition, it improves any deviations from the orbit. Generally, it is composed of 9 stations (5 for monitoring, 3 for data and 2 for general).

Thanks to all this, the GPS stands out with the following peculiarities, in particular:

Shelf life : 7,5 years.
Altitude : 20 km.
Period : 11 hours 58 minutes (or 12 sidereal hours).
tilt : 55 degrees around the earth's equator.
HIGHLIGHTS : 1 ns.
User capacity : unlimited.
COVER : in the whole world.
Coordinate system : 8 000.

On the other hand, to characterize this recognized global positioning system, it is necessary to know its main applications , beyond its specific operation in the IT environment.

Therefore, below we specify its most important uses:

Military use : it is no secret that it is the main application of GPS. Since, many years ago, it was born as a tool to develop a system capable of provide the exact location of a person or object and even its speed . With this, it also enabled the development of radio navigation technologies and the launch of weapons to a specific geographic location.
Public and private security : In the field of security, the Global Positioning System also has multiple applications. Either for anti-theft measures, as a personal security tool or for its integration into alarms .
Air, sea and land navigation : Although these tools were used by the military, the truth is that many of them ended up being used by civilians in different media based on sea, air and land navigation.
Engineering and mapping : Of course, GPS is also used to collect precise and reliable data from all over the world in order to carry out projects in this field. It also allows steps , monitoring what is happening in the large structures in real time overload, detect the tremors land located at a certain point, etc. .
Sport : Besides its computer applications, GPS is also widely used for sports. Since he allows you to monitor the progress of certain workouts and thus optimize performance with absolute precision by obtaining data such as running pace, distance traveled, delay time, etc.

History and origin When was it created, who made it and how did GPS evolve?

Basically, the origin of GPS as a global positioning system dates back to the period between 1957 and 1960 . Since 1957, the first artificial satellite called "Sputnik" launched by the Soviet Union a born . Then, from the 1960s, the OMEGA land navigation system pioneered this technology and became the world's first radio navigation system .

However, the notable limitations of these systems made it necessary a more universal navigation solution which could guarantee higher precision. From there, the U.S. Navy began experimenting with a satellite navigation system for provide up-to-date and accurate position observations in its fleet systems .

In principle, this system of thought should meet global requirements to cover the entire surface of the Earth. In addition, it had to show continuous operation without the atmospheric conditions being able to affect it and, as if that were not enough, it should also allow its use in aviation. Therefore, the fundamentals of GPS correspond to a system: global, continuous, dynamic and precise .

But, under these conditions, the "TRANSIT" system was born in 1964 which, three years later, became available for commercial and military use. Which, mainly, had a constellation of 6 satellites in low polar orbit and at a height of 1074 km . However, although it did reach comprehensiveness, it was not constant. For this reason, experts continued to look for other solutions to be able to answer the foundations of a truly optimal global positioning system.

In view of this, in 1967. , the US Navy launched a satellite called "Timation" who succeeded in ensuring the viability of placing precise clocks in space in order to maintain the necessary continuity for GPS . Thanks to that, in 1973. , they were able to combine programs designed by the United States Air Force and Navy to promote a new navigation technology project known as the "Navigation Technology Program" . Which was later renamed "NAVSTAR GPS" .

So they started to develop 11 additional satellites on an experimental basis to improve the performance of NAVSTAR with a total of 18 satellites planned. With that, in 1985. , they succeeded in completing the current constellation and thanks to its remarkable constancy, dynamism and precision, they were able to declare it as a system with "Full operational capacity" by adding 24 satellites with three alternatives in 1993. . With which, the famous GPS that we know today was launched.

How does the Global Positioning System work and how accurate is its data?

Regarding its operation, we emphasize that the GPS satellites (24 in total) are in charge of circulating the Earth twice a day , or every 12 hours. Which they do in an exact orbit to be able to transmit signal information to Earth .

The GPS receivers then acquire this information and use triangulation or trilateration to measure or calculate the exact location of the user. Considering that, for this, said receiver concentrates on the comparison of transmission and reception times around a signal transmitted by the satellite . So you can find the user's position to display.

Therefore, through the process of trilateration, the position of the receptor can be discovered as follows:

Each satellite of the set indicates that the receiver is at a point on the surface of the sphere . Basically centered on the satellite itself and a radius equal to the total distance from the receiver.
After getting the data in question based on two satellites , the result will be a circle that illustrates when the two spheres intersect at a certain point where the receiver is located.
On the base of informations by a third satellite , the lack of synchronization between satellite clocks and GPS receivers is eliminated. With that, an exact 3D position is found based on latitude, longitude and altitude .

So, in layman's terms, the GPS receiver must be connected to the signal of at least two or three satellites to find the 2D position and follow the movement. Later, with another satellite in sight, the receiver manages to calculate the user's 3D position and thanks to this, it will also be able to calculate other data of interest (speed, heading, distance traveled, distance to destination, track, time of departure, sunset, etc.).

Then we will see the accuracy of the data:

But how accurate is this data?

Now, you are probably wondering how accurate the Global Positioning System is compared to the information it provides. Therefore, we recall that GPS systems have a certain degree of random error which can fluctuate between 15 meters and 100 meters . In evaluating this, its accuracy will depend on the number of satellites visible at any given time, as well as the user's position and certain atmospheric factors. However, it should be noted that at Currently, GPS receivers are very accurate .

“UPDATE ✅ Do you want to know more about GPS, what are its origins and impact on the world? ⭐ ENTER HERE ⭐ and learn all about SCRATCH! ✅ "

Due to the multi-channel parallel design they contain. Well, by default they maintain strong ties, whether you are in urban environments with tall buildings or in a dense forest, for example. Apart from this, users can also get better accuracy with differential GPS (DGPS) , Known under the name of "Differential global positioning system" . This is ideal for correcting existing errors in satellite orbits and perfecting the position provided by GPS.

While it works as follows:

A set of fixed ground stations is responsible for comparing the position provided by the GPS and the real situation, for establish the error at any time .
Once this calculated error , it is communicated and distributed to the user's antennas and thus, the teams of the same focus on applying said error to discover the correct position (based on a 10 meter margin, maximum).

All of this is carried out thanks to the DGPS structure which includes the following elements: Monitored station as a reference (which has: a GPS receiver, a microprocessor and a transmitter) and user equipment (it contains a DGPS receiver which is a GPS with a monitored station data link receiver).

GPS signal What is its frequency and what aspects influence it?

If true, the GPS signal provides "Time of the week" exact, based on the atomic clock on board the satellite, the GPS week number and a status report. So each transmission lasts 30 seconds and carries 1 bits of encoded data which, basically, is that a GPS signal has three bits of summary information.

Which are :

A pseudo-random code : It is an identification number which allows to know which satellite transmits the information. This code is usually found on your Garmin GPS device .
Ephemeris data : they provide information to the GPS receiver, indicating where each GPS satellite should be at a given time of the day. Those data present orbital information for each element of the system .
Data almanac : These are data transmitted by each satellite, permanently. They usually provide information about the status of the satellite, the current date and time. THU are essential to determine a position .

For its part, each GPS satellite emits a navigation message at 50 bits per second , continuously, on the microwave transport frequency of 1600 MHz, but specifically, GPS satellites are characterized by emitting two weak radio signals. power known as "L1" and "L2" .

In the case of GPS for civilian use, it uses essentially the frequency L1 in the UHF band which specifically provides 1575,42 MHz . While, the L2 signal offers 1227,6 MHz . At this frequency, the civilian GPS signal can cross clouds, plastic and glass (i.e. line of sight). But, it cannot be transmitted by most solid objects, such as mountains or buildings .

This means that, normally, the frequency of the GPS signal is influenced by several aspects that can obstruct it, among which we mention:

Receiver clock errors : Atomic clocks on board GPS satellites are generally accurate. However, the receiver's built-in clock is not as precise as it is and therefore may have slight timing errors affecting the GPS signal.
Orbital errors : These are ephemeris errors and inaccuracies in the location reported by the satellite .
Delays in the troposphere and ionosphere : during its passage through the atmosphere, the satellite signal can decrease . However, the GPS system has an additional model which calculates an average delay in order to correct this type of error.
Intentional degradation of the satellite signal : Known as "Selective availability", it corresponds to a deliberate degradation of the signal formerly imposed by the United States Department of Defense. Thus, they sought to prevent military adversaries use high precision GPS signals . But, it has currently been disabled to improve the GPS signal to civilian receivers.
Number of visible satellites : Electronic interference, terrain, buildings and dense foliage often block GPS signal reception and thus cause position errors or missing readings. Because less a GSP receiver peut "See" of satellites , the lower its precision .
Multipath signal : This is a problem that occurs when the GPS signal is reflected from some objects (rocky surfaces, tall buildings, etc.) before it reaches the receiver. This is why the travel time of this signal increases and generates notable errors .