Sat Nav

satellite navigation

Shopping online for Sat Nav & Car Electronics from a wide selection at Electronics & Photo Store. satnav (countable and uncountable, multiple satnavs). ("Informal") A satellite navigation system.

("Informal") A receiver for a satellite navigation system. Satellite navigation or satellite navigation system is a system that enables autonomous geo-spatial positioning by means of satellites.

Best Sat Nav Offers 2018

Satellite navs are a must for any vehicle, but there are so many different models to select from. At first glance it can seem a bit overpowering. Please refer to our Buyer's Guide below for details. When streets are changing and new buildings are being built, your navigation system can quickly become obsolete, giving you more travel times or no longer getting to your destinations.

Fortunately, most vendors publish new charts often, and it's simple to get them onto your navigation device. Please see our guideline below to learn how you can do this.

chip="mw-headline" id="Classification">Classification[edit]>>

Sat-nav or sat-nav is a system that enables independent geo-spatial localisation by means of spacecraft. This enables small electronics devices to pinpoint their position (length, width and height/elevation) with high accuracy (within a few meters) using timing signal sent by a line of vision via spacecraft.

It can be used to determine the location, navigate or track the location of a receiver-equipped object (satellite positioning). While Satnav operates independent of telephone or web access, these technology can increase the value of the resulting location information. GNSS (Global Sat Nav System) is a system of satellites with worldwide cover.

Since December 2016[update] only the United States' GPS (Global Positioning System), the Russian GLONASS, the Chinese BeiDou Navigation Satellite System (BDS) and the Galileo of the European Union are still GNSS (Global Navigation Satellite System). Galileo GNSS of the European Union should be fully functional by 2020. China is in the midst of developing its BeiDou navigation satellite system into the BeiDou-2 GNSS system by 2020.

India, France and Japan are also working on the development of local navigational and grafting regimes. As a rule, overall system cover is provided by a combination of 18-30 mid -earth orbiting spacecraft (MEO) distributed over several levels of orbiting. However, the real system varies but uses tendencies of >50 and period orbits of about 12 h (at an elevation of about 20,000 kilometers or 12,000 miles).

Nuclear satellite radionavigation system, currently GPS (United States), GLONASS (Russian Federation), Galileo (European Union) and Compass (China). Satellite-supported global augmentation system (SBAS) such as Omnistar and StarFire. SBAS regional offices include WAAS (USA), EGNOS (EU), MSAS (Japan) and GAGAN (India). Satellite regional radionavigation products such as Beidou from China, NAVIC from India and KZSS from Japan.

Kontinentale ground augmentation systems (GBAS), z.B. das australische GRAS und die gemeinsame US Coast Guard, Canadian Coast Guard, US Army Corps of Engineers und US Department of Transportation National Differential GPS (DGPS). GBAS and CORS network on a local level. Terrestrial radionavigation has been in use for a long time.

DECCA, LORAN, GEE and Omega use long-wave transmitter technology to transmit a wireless impulse from a known "master" site, followed by a repetitive impulse from several "slave" emitters. The US Naval Observatory (USNO) continually monitored the exact orbit of these spacecraft to guarantee precision.

The USNO sends the information to the spacecraft because the satellites have different orbits. Follow-up transmissions from an upgraded spacecraft would contain its last few ephemerides. Today's sys-tems are more straightforward. It transmits a spacecraft information containing trajectory information (from which the location of the spacecraft can be calculated) and the exact timing of the transmission.

It uses an atclock to keep all spacecraft in the configuration in sync. Recipients compare the coded transmitting times of three (at ocean level) or four different spacecraft and measure the flying times to each of them. Multiple such readings can be made simultaneously on different spacecraft, so that with an adjusted variation of the trilatation a continuous fix can be created in near-realtime: see GPS position computation for detail.

In the case of high-speed recipients, however, the location of the message will move when receiving messages from multiple spacecraft. Also, the wireless waves decelerate slightly as they travel through the atmosphere, and this deceleration will vary with the recipient's inclination to the spacecraft, as it changes the range through the atmosphere.

Thus, the base calculation tries to find the closest line that runs tangentially to four flattened ball dishes that are centered on four sat. Sat-nav receiver reduces error by using a combination of signal from more than one spacecraft and several correlator and then using technologies such as Kalman filtration to consolidate noise, partially and continuously varying information into a common estimation of location, timing and speed.

Originally, the motivations for sat-nav were for defence use. The use of sat-nav enables the precise supply of arms to destinations, significantly enhancing their mortality and at the same time decreasing the number of accidental victims of misguided-armament. Sat-nav enables the armed services to orient and localise themselves more readily, thereby lessening the nebula of their warfare.

It is also the capacity to refuse the provision of navigational information by means of space. Operators of such a system have the potential to reduce or abolish the provision of GPS in any desired area. United States Global Positioning System (GPS) comprises up to 32 mid-size orbiting spacecraft in six different levels of space, with the precise number of spacecraft changing as older spacecraft are decommissioned and substituted.

In operation since 1978 and available worldwide since 1994, GPS is currently the most widely used GPS system in the global market. Formerly known as the Sovjet and now known as the Russia's Global'naya Navigatsionnaya Sputnikovaya Sistema (GLObal NAV igation Satelite System or GLONASS) is a spaceborne satelite positioning system that provides a civil radio positioning satelite and is also used by the RF Air and Aerospace Forces.

With 24 satellite stations GLONASS is represented all over the world. In March 2002, the European Union and the European Space Agency decided to establish a separate GPS replacement, the so-called Galileo position system. The Galileo system went into operation on 15 December 2016 (Global Early Operating Capability (EOC)). 6 ] With an estimate of 3 billion[7], the system of 30 MEO spacecraft was initially expected to go into operation in 2010.

8 ] The first test spacecraft was launch on 28 December 2005. 9 ] Galileo should be fully compliant with the modernised Galileo system. Recipients will be able to use Galileo and Galileo combined to significantly improve precision. By 2020, Galileo is fully operational at a much higher price.

1 ] The primary modulator in the Galileo Open Servicesignal is the Composite Binary Offset Carrier (CBOC) modulator. It has announced that it will complement the whole second generating Beidou navigation satellite system (BDS or BeiDou-2, formerly known as COMPASS) by extending the existing Asia-Pacific services to include comprehensive satellite services by 2020.

2 ] The BeiDou-2 system will comprise 30 MEO spacecraft and five geo-stationary spacecraft. An Asian-Pacific region satellite with 16 spacecraft was finalized by December 2012. China's Asia-Pacific satellite system (16 satellites) to be extended to the entire BeiDou-2 system, consisting of all 35 spacecraft, by 2020.

CoverageRegional, Satellites5 GEO, 30 MEO24 by theme, 14 operationally, 4 launch, 24 by theme3 GEO, 5 GSO MEO4 by end 2010, Status22 operationally, Leading edge technology, Leica Geosystems Satellites5 GEO, Leica Geosystems Satellites5 GEO, Satellites5 GEO 4, 24 GEO4, 5 GSO MEO4, and more, and more, is a way to improve the features of a navigational system, such as precision, dependability and access, and more, and more, with more, and more, by integrating information from outside the computation system, e.g. the Wide Area augmentation system, the European Geostationary Navigations Overlay Service, the Multifunctional Satellite augmentation system, Differenerential GPS, GAGAN (GPS Aided GEO Augmented Navigation) and ISS.

Both of the low earth orbiting telephone satellites currently in operation are capable of tracking a few kilometres of radio receiver unit with the aid of double displacement math. Jumping up ^ orbiting times and velocities are computed with the following relations: 4?²R = T²GM and V²R = GM, where R1 = radii of the circular path in meters, T = orbiting time in seconds, C = orbiting velocity in m/s, W = gravity constants ? 6.

Skip up to: a bar "Galileo goes on! Skip up to: a BMW "Beidou global satnav in 2020". Jewellery panel, A, 1973, Application of the Kalman filter to real-time synchronous sat-nav, 945-952, Proceedings out of the 9th International Symposium on Space Technology and Science, Tokyo.

Jumping up ^ "Galileo goes on! Leap up ^ "Boost to Galileo sat-nav system". Leap to the top ^ "Commission places large orders for the commissioning of Galileo in early 2014". "launching the first Indian Sat Nav spacecraft next year." Leap to the top ^ "India is building a configuration of 7 navigational satellite by 2012".

Leap up ^ "ISRO: All 7 IRNSS satellites in orbit by March". JAXA Quasi-Zenith Satellite System". Top ^ "Information and Analysis Centre for Positioning, Navigation and Timing".

Mehr zum Thema