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what’s the use?
When the driver does not recognize the road by satellite positioning, using the screen and voice prompts to guide to the destination.
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Advantages:
· need information on nearby gas station or restaurant and accommodation, you can queries to the desired place surrounding the position, navigation go.
· when driving to the upcoming intersection, GPS will be displayed in front of the intersection in advance which lane is straight lanes, turning lanes and other information, and advance line.
Optional optimal route, a detour to avoid the waste of travel time and the like. GPS navigation systems are equipped with the shortest distance, recommended roads, high-speed priority mode and other settings, you can choose on demand.
· Today’s GPS navigation system also features real-time traffic feature, road congestion will be displayed in real time, to remind you to avoid congested roads.
· You avoid violation fines because of unfamiliar roads caused. Some navigation in the face of the bus lane, no U-turns, one-way road even gun cases and other sections will prompt you to avoid violations.
· GPS is not easily affected by the weather, coverage of up to 98 percentage on the ground, quickly and efficiently a wide range of applications, and scalable range of services.
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Myth:
· Car GPS precise positioning can not be done, inThere may be a small range of error location and guidance, especially in the densely overpasses and other road sections may be errors in judgment upon which your road.
· GPS function will fail. Where satellite signals can not be covered, GPS can not accurately locate and operate other functions, such as underground garages and other places.
· GPS information display can not be synchronized with the urban road construction, new roads if no navigation map information, we recommend that you update.
· Some models do not place GPS satellite signals can still follow the vehicle steering, travel, this is the GPS system built-in gyro effect, be able to operate the vehicle displacement, but accuracy is not high.
· Today’s GPS navigation systems are not necessarily all on the big screen in the control display, some models can simplify navigation information is displayed on the instrument heads-up display, or HUD, and even use the phone to sync to display the vehicle.
· once GPS navigation systems require an external storage device such as CD-ROM with, and now vehicles are generally the map information stored in the vehicle comes with a built-in hard disk.
· GPS navigation system can be achieved through post-installation, optional wide variety of brands on the market, you can choose on demand.
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Background:
global positioning system (English: GlobalPositioningSystem, commonly referred to as GPS), also known as the Global satellite positioning system. Initially the system by the US government in the 1970s began to develop in 1994 and fully completed. Users only need to have a GPS receiver to use this service at no extra charge. Civilian GPS signal is divided into Standard Positioning Service (SPS, StandardPositioningService) military regulations and precise positioning service (PPS, PrecisePositioningService) categories. Since the SPS without any authorization to any use, because the United States had to worry about hostile states or organizations will use SPS to attack the United States, it is artificially added to selection bias in the civilian signal (ie SA policy, SelectiveAvailability) to reduce its accuracy, a final positioning accuracy in about 100 m; ten meters accuracy in the following military specifications. After 2000, the Clinton administration decided to cancel the interference with civil signals. So now civilian GPS positioning accuracy can reach about ten meters.
In addition to the US GPS system, satellite global positioning system GLONASS Russian system is currently running Beidou satellite navigation and positioning system of the People’s Republic of China. In early 1999 the EU formally launched the “Galileo” program, to deploy a new generation of satellite positioning. The program consists of 27 operational satellites and three preparatory satellites, global coverage, location accuracy of a few meters, also compatible with the US GPS system, a total investment of 3.5 billion euros. Now launch three experimental satellites, not to provide services. International Committee on Global Navigation Satellite System as an informal body to the United Nations. Its purpose is to promote civil satellite-based positioning, navigation, timing and value-added services related to the issue of cooperation and development, and various issues of compatibility and interoperability of global navigation satellite systems.
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Working principle:
GPS system consists of a space constellation part, the ground control segment and the user equipment parts .
space constellation section
the GPS satellite constellation consists of 24 satellites, of which 21 is operating satellites, of three spare satellites. 24 satellites evenly distributed in six orbital planes, i.e., four satellites in each orbital plane. Satellite orbit the Earth’s surface with respect to the equatorial plane of the orbit inclination angle is 55 °, each of the ascending node of orbital plane ascension difference of 60 °, the satellite orbit on a satellite in orbit plane of the respective cross-plane than lift adjacent westAdvance angle from 30 °. The purpose of this arrangement is to ensure that anywhere in the world, any time can be observed at least four satellites.
GPS satellite by the Rockefeller International space developed, satellite, weighing 774kg, the service life of seven years. Satellite using the honeycomb structure body was cylindrical, having a diameter of 1.5m. Satellite sides with two pairs of leaves sense of orientation of the solar cell windsurfing (BLOCKI), the entire length of 5.33m to solar area of 7.2m ^ 2. Sense of orientation wings battery control system windsurfing rotating the plate surface is always aligned with the sun, continue to provide power to the satellite, and three groups of 15Ah rechargeable nickel-cadmium batteries, can work to ensure that the satellite in the Earth shadow portion. In the bottom of the multi-beam directional antenna with 12 units of stars, capable of transmitting an opening angle of about 30 degrees two L-band (19cm and 24cm wave) signals. Both end faces of stars with omnidirectional remote telemetry antenna for communication with ground control networks. In addition satellite attitude control system is also equipped with a control system and orbit, the satellite remains visible so that the ground at an appropriate height and angle, an accurate alignment of the satellite.
apparent from the GPS system works, the more accurate onboard clock, the higher positioning accuracy. Early tests using the type of satellite Hopkins developed by a quartz oscillator, the relative frequency stability of 10 ^ {–11} / sec. Error of 14m. After 1974, GPS satellites rubidium atomic clock, the relative frequency stability of 10 ^ {–12} / sec, errors 8m. 1977, BOKCKII type with frequency and time after Mas Systems developed relatively stable cesium clock frequency of 10 ^ {–13} / sec, the error is reduced to 2.9m. In 1981, Hughes developed relatively stable frequency of 10 ^ {–14} / sec so that atomic hydrogen BLOCKIIR type satellite error is only 1m.
ground monitoring section
mainly by the ground control master station 1 (MasterControlStation, referred to as MCS), 4 terrestrial antenna stations (GroundAntenna) and six stations (MonitorStation) composition.
master control station located Sheri Dover Air Force Base in Colorado, Is the whole management center and technical center ground monitoring system. There is also a Maryland Gettysburg standby master station to enable the event of an emergency.
There are four injection plants, which are located in the South Pacific Marshall Islands Kwajalein, Ascension Island in the Atlantic Ocean British dependencies, British Indian Ocean Territory Diego Garcia Island and is located in United States, Colorado Colorado Springs, Colorado. Implantation station the role of the master station satellite ephemeris calculated, navigation data and other information to the appropriate satellite injected.
Stations implantation station also, in addition to Hawaii, and located at stations 2 Canaveral, so there are six stations. Stations main role is to collect GPS satellite data and the local environmental data, and then sent to the master station.
User Part
The user equipment is mainly a GPS receiver, the main role is the received signal from the GPS satellite and the user information calculation using the three-dimensional position and the time of coming.
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Further reading:
more personalized navigation services as well as third-party agencies pay extended services, such as: G-BOOK, ONSTAR and other artificial intelligence to drive online assistant, able to assist you with a set destination through voice, looking at the surrounding roads for your route guidance voice, driving do not have their own operating system, GPS, even it can automatically detect and provide timely help in times of crisis, improve your driving safety.