Gps wikipedia

Ya kabud ganap a gaganang GNSS king yatu, maliari yang gamitang timawa ampong alang bayad, at maras, magsilbi ya kareng sibilian king pamaglayag. Gagamit yang constellation da reng pilatan ning 24 ampng satellite a Medium Earth Orbit a magparalang eksaktung senias a microwavea sasaup kareng GPS receiver a mangarcula king salukuyan dang pusisiun o kabilianing oras, ampo ing karelang bilis o salusu velocity.

Manibat aniang ganap deng pepagana aniangmeging maleparan ing pamangamit ning GPS antimong saup king pamaglayag king mabilug a yatu, ampong metung a maulagang kasangkapan king pamangawang mapapamaniukad gabun, negosiu, gamit a pang-siensia, ampong hobby antimong en:geocaching. Bukud kaniti, magsilbi ya ing saktung time reference kareng dakal a pigagamitan, alimbawa ing sientipicung pamanigaral kareng ayun. Metung ya muring maulagang pamangailangan king pamiagnan-agnan da reng cellular networkanti ing Qualcomm CDMA air interface a gagamitan da reng dakal a wireless carriers kareng miayaliwang bangsa.

Template:Nautical portal. Ibat king Wikipedia. Charting a Course Toward Global Navigation. The Aerospace Corporation. Retrieved on Suglung a pang-kapamahalan GPS.

Also includes satellite almanac data. Personal Location Tracking and Publishing Service. Dana, Peter H. Chadha, Kanwar. David L.

GPS signals

Kategorya : All articles with unsourced statements Articles with unsourced statements since November Aerospace engineering Articles with separate introductions Avionics Command and control Geodesy Geographical technology GPS Hiking equipment Missile guidance Navigation Navigational equipment Nuclear command and control Outdoor locating games Radio navigation Surveying Technology systems Weapon guidance Wireless locating American inventions.

Deng pirinan-lagyu Namespaces Bulung Pamisabi-sabi. Pamaglawe Basan Lon ya ing pikuanan Lawen ya ing amlat. Deng pakasuglung keti Miyalilan a makaugne Maglulan simpan file Bulung a makabukud Suglung a permanenti Page information Banggitan ya ing articulung ini Wikidata item. Wikimedia Commons. Ing panimanman ning metung a talagulis artist's conception keng GPS satellite a dudurut king yatu. Ing automotive navigation system king metung a taxi. Magagamit no kareng dakal a cellphone deng GPS receiver.Global Positioning System GPS satellites broadcast microwave signals to enable GPS receivers on or near the Earth's surface to determine location and time, and to derive velocity.

gps wikipedia

The system is operated by the U. Department of Defense DoD for use by both the military and the general public. GPS signals include ranging signals, used to measure the distance to the satellite, and navigation messages. The navigation messages include ephemeris data, used to calculate the position of each satellite in orbit, and information about the time and status of the entire satellite constellation, called the almanac.

There are four signals available for civilian use. The other signals are called modernized signals and are not broadcast by all satellites. In addition, there are restricted signals with published frequencies and chip rates but encrypted coding intended to be used only by authorized parties. Some limited use of restricted signals can still be made by civilians without decryption; this is called codeless and semi-codeless access, and is officially supported.

The GPS satellites called space vehicles in the GPS interface specification documents transmit simultaneously several ranging codes and navigation data using binary phase-shift keying BPSK. Only a limited number of central frequencies are used; satellites using the same frequency are distinguished by using different ranging codes; in other words, GPS uses code division multiple access.

Some satellites transmit several BPSK streams at the same frequency in quadrature, in a form of quadrature amplitude modulation. However, unlike typical QAM systems where a single bit stream is split in two half-symbol-rate bit streams to improve spectral efficiencyin GPS signals the in-phase and quadrature components are modulated by separate but functionally related bit streams. Satellites are uniquely identified by a serial number called space vehicle number SVN which does not change during its lifetime.

In addition, all operating satellites are numbered with a space vehicle identifier SV ID and pseudorandom noise number PRN number which uniquely identifies the ranging codes that a satellite uses. There is a fixed one-to-one correspondence between SV identifiers and PRN numbers described in the interface specification.

These codes only match up, or strongly autocorrelate when they are almost exactly aligned. In other words, the PRN codes are highly orthogonal to one another.

Receivers track these codes well within one chip of accuracy, so measurement errors are considerably smaller than m. Different codes are obtained by selectively delaying one of those bit streams. The arguments of the functions therein are the number of bits or chips since their epochs, starting at 0.The Global Positioning system broadcasts a date, including a weekly counter which is stored in only ten binary digits.

The range is therefore 0— After the internal value "rolls over", changing to zero again. Software which is not coded to anticipate the rollover to zero may stop working or could be moved back in time by 20 or 40 years. GPS is not only used for positioning, but also for accurate time. Time is used to accurately synchronize payment operations, broadcasters, and mobile operators.

NavCen issued an advisory prior to the rollover stating that some manufacturers have not fixed the issue. The second rollover occurred on the night of April 6 to April 7,when GPS Weekrepresented as in the counter, advanced and rolled over to 0 within the counter.

gps wikipedia

Products known to have been affected by the rollover include Honeywell 's flight management and navigation software that caused delays for a KLM flight and cancellations for numerous flights in China because the technicians failed to patch the software.

Prior to return to normal standard time from daylight saving time during the morning of November 3,Apple issued a warning to owners of iPhone and iPadwhich were sold beforethat these Apple products could lose internet.

A third rollover may happen in November The above rollovers are due to a ten-bit week number; the more recent CNAV protocol, successor to the original NAV protocol, uses thirteen-bit week numbers, which amounts to a year cycle; therefore, using the same epoch ofthe first rollover won't be until From Wikipedia, the free encyclopedia. Retrieved Retrieved 3 September Ars Technica. Mobile Syrup. GPS World. The Verge. Des Moines, Iowa.

gps wikipedia

October 31, Retrieved October 31, — via CNN. Hidden categories: CS1 Czech-language sources cs. Namespaces Article Talk. Views Read Edit View history. Help Learn to edit Community portal Recent changes Upload file. Download as PDF Printable version.A Global Positioning Systemalso known as GPSis a system of satellites designed to help navigate on the Earth, in the air, and on water.

A GPS receiver shows where it is. It may also show how fast it is moving, which direction it is going, how high it is, and maybe how fast it is going up or down.

Many GPS receivers have information about places. GPSs for automobiles have travel data like road mapshotelsrestaurantsand service stations. GPSs for boats contain nautical charts of harborsmarinasshallow water, rocks, and waterways.

Global Positioning System

Other GPS receivers are made for air navigationhiking and backpacking, bicyclingor many other activities. The majority are in smartphones. Most GPS receivers can record where they have been, and help plan a journey. While traveling a planned journey, it predicts the time to the next destination.

A GPS unit takes radio signals from satellites in space in orbit around the Earth. The orbital period is 11 hours and 58 minutes. The radio signals contain information about the time and position of the satellite, including its ephemeris. The GPS receiver subtracts the current time from the time the signal was sent. The difference is how long ago the signal was sent. The time difference multiplied by the speed of light is the distance to the satellite. The GPS unit uses trigonometry to calculate where it is from each satellite's position and distance.

Usually there must be at least four satellites to solve the geometric equations. A GPS receiver can calculate its position many times in one second. A GPS unit can usually also calculate its current speed. Cheap ones like in a mobile phone do this by comparing present position with recent position.The GPS does not require the user to transmit any data, and it operates independently of any telephonic or internet reception, though these technologies can enhance the usefulness of the GPS positioning information.

The GPS provides critical positioning capabilities to military, civil, and commercial users around the world. The United States government created the system, maintains it, and makes it freely accessible to anyone with a GPS receiver. The GPS project was started by the U.

Department of Defense inwith the first prototype spacecraft launched in and the full constellation of 24 satellites operational in Originally limited to use by the United States military, civilian use was allowed from the s following an executive order from President Ronald Reagan. Inthe U. The GPS service is provided by the United States government, which can selectively deny access to the system, as happened to the Indian military in during the Kargil Waror degrade the service at any time.

The latest stage of accuracy enhancement uses the L5 band and is now fully deployed. GPS receivers released in that use the L5 band can have much higher accuracy, pinpointing to within 30 centimeters or The GPS project was launched in the United States in to overcome the limitations of previous navigation systems, [15] integrating ideas from several predecessors, including classified engineering design studies from the s.

GPS Week Number Rollover

The U. Department of Defense developed the system, which originally used 24 satellites. It was initially developed for use by the United States military and became fully operational in Civilian use was allowed from the s. Roger L. InFriedwardt Winterberg proposed a test of general relativity — detecting time slowing in a strong gravitational field using accurate atomic clocks placed in orbit inside artificial satellites.

Special and general relativity predict that the clocks on the GPS satellites would be seen by the Earth's observers to run 38 microseconds faster per day than the clocks on the Earth. This was corrected for in the design of GPS. Early the next year, Frank McClure, the deputy director of the APL, asked Guier and Weiffenbach to investigate the inverse problem—pinpointing the user's location, given the satellite's.

At the time, the Navy was developing the submarine-launched Polaris missile, which required them to know the submarine's location. Navy developed the Timation satellite, which proved the feasibility of placing accurate clocks in space, a technology required for GPS. In the s, the ground-based OMEGA navigation system, based on phase comparison of signal transmission from pairs of stations, [25] became the first worldwide radio navigation system. Limitations of these systems drove the need for a more universal navigation solution with greater accuracy.

Although there were wide needs for accurate navigation in military and civilian sectors, almost none of those was seen as justification for the billions of dollars it would cost in research, development, deployment, and operation of a constellation of navigation satellites.

During the Cold War arms racethe nuclear threat to the existence of the United States was the one need that did justify this cost in the view of the United States Congress. This deterrent effect is why GPS was funded. It is also the reason for the ultra-secrecy at that time. Considered vital to the nuclear deterrence posture, accurate determination of the SLBM launch position was a force multiplier.

Precise navigation would enable United States ballistic missile submarines to get an accurate fix of their positions before they launched their SLBMs. The Navy and Air Force were developing their own technologies in parallel to solve what was essentially the same problem.

The Naval Research Laboratory continued making advances with their Timation Time Navigation satellites, first launched inwith the third one in carrying the first atomic clock into orbit. A fourth ground-based station, at an undetermined position, could then use those signals to fix its location precisely. With these parallel developments in the s, it was realized that a superior system could be developed by synthesizing the best technologies from B, Transit, Timation, and SECOR in a multi-service program.

Satellite orbital position errors, induced by variations in the gravity field and radar refraction among others, had to be resolved. A team led by Harold L Jury of Pan Am Aerospace Division in Florida from —, used real-time data assimilation and recursive estimation to do so, reducing systematic and residual errors to a manageable level to permit accurate navigation.The sweet-shooting offense of New Orleans will go head-to-head against the porous defense of Sacramento.

The Pelicans currently rank fifth in effective field goal percentage (0. The Pelicans should have the edge on that end of the court. Sacramento heads into the game with records of 7-17 straight up (SU) and 10-11-3 against the spread (ATS). Meanwhile, New Orleans owns records of 13-12 SU and 14-11 ATS.

Vegas tends to place the total low when the Pelicans are involved, as 56. Both teams have had a player take their game to the next level over their last five games.

This is the second game of the season between these two teams. In the first, Cousins scored a game-high 41 points and the Pelicans beat the Kings 114-106, covering as 1-point underdogs. He also recorded 23 rebounds and six assists. The game finished with a total of 220 points, which was 16 points above the projected point total of 204 points.

New Orleans had a much better offensive rebounding percentage (25. New Orleans ranks second in assists per game (26. The Pelicans rank 12th in three pointers attempted per game (30. Sacramento ranks third in points off turnovers allowed per game (15. The Kings rank 10th in steals per game (8. New Orleans ranks second in points in the paint per game (51. The Kings rank 12th in fast break points allowed per game (10. New Orleans averages 12. Sacramento ranks 15th in second chance points allowed per game (12.

During their last five games, the Pelicans have scored an average of 114. Tags New Orleans Pelicans Sacramento KingsThe Creighton Bluejays (6-2) matchup against the Nebraska Cornhuskers (7-3) at CenturyLink Center Omaha on Saturday night.

The Oklahoma State Cowboys (7-1) welcome the No. ET on Friday, December 8 on NBC Sacramento Kings vs. At home, New Orleans is 6-6 ATS with 7 overs and 5 unders.

Sacramento is 3-2 when they allow below 100 points, while New Orleans is 4-0. When scoring over 100 points, the Kings are 4-4 and the Pelicans are 11-7. New Orleans ranks 14th in rebounds per game (44.A Model Object has the following properties: Creating a model is a process that can take just a few seconds or a few days depending on the size of the dataset used as input and on the workload of BigML's systems.

The model goes through a number of states until its fully completed. Through the status field in the model you can determine when the model has been fully processed and ready to be used to create predictions. Support is a number from 0 to 1 that specifies the minimum fraction of the total number of instances that a given branch must cover to be retained in the resulting tree. If you repeat the support parameter in the query string, the last one is used.

Non-parseable support values are ignored. Value is a concrete value or interval of values (for regression trees) that a leaf must predict to be kept in the returning tree. Intervals can be closed or open in either end. Confidence is a concrete value or interval of values that a leaf must have to be kept in the returning tree.

The specification of intervals follows the same conventions as those of value. Since confidences are a continuous value, the most common case will be asking for a range, but the service will accept also individual values. It's also possible to specify both a value and a confidence. Finally, note that it is also possible to specify support, value, and confidence parameters in the same query. Filtering and Paginating Fields from a Model A model might be composed of hundreds or even thousands of fields.

Thus when retrieving a model, it's possible to specify that only a subset of fields be retrieved, by using any combination of the following parameters in the query string (unrecognized parameters are ignored): Fields Filter Parameters Parameter TypeDescription fields optional Comma-separated list A comma-separated list of field IDs to retrieve. To update a model, you need to PUT an object containing the fields that you want to update to the model' s base URL.

Once you delete a model, it is permanently deleted. If you try to delete a model a second time, or a model that does not exist, you will receive a "404 not found" response. However, if you try to delete a model that is being used at the moment, then BigML. To list all the models, you can use the model base URL. By default, only the 20 most recent models will be returned. You can get your list of models directly in your browser using your own username and API key with the following links.

You can also paginate, filter, and order your models. This is valid for both regression and classification models. Objective Weights: submitting a specific weight for each class in classification models. Automatic Balancing: setting the balance argument to true to let BigML automatically balance all the classes evenly.


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