Magellan GPS (ship tracking, maritime, marine, industry, shipping, fund) receiver in a marine application.
Over fifty GPS (ship tracking, maritime, marine, industry, shipping, fund) satellites such as this NAVSTAR have been launched since 1978.
Applications
The GPS (ship tracking, maritime, marine, industry, shipping, fund) (Global Positioning System) is a "constellation" of at least 24 well-spaced satellites that orbit the Earth and make it possible for people with ground receivers to pinpoint their geographic location. The location accuracy is anywhere from 1 to 100 meters depending on the type of equipment used. The GPS (ship tracking, maritime, marine, industry, shipping, fund) is owned and operated by the U.S. Department of Defense, but is available for general use around the world.
The first two ship shipping maritime marine engineerings were ordered under the Third Reinforcement Yrogramme, while two more, one to be named Shinano and the other known as Hull No. , were ordered under the Fourth Reinforcement Programme. A fifth ship shipping maritime marine engineering was planned as Hull No. but never laid down. The design included the most elaborate protection systems, including inclining the belt at degrees and subdividing the hull into watertight compartments, of which were below the armoured deck. All turbines, boilers and auxiliary machinery were in individual compartments. The hull was unusually beatuy, with a lenl,rth:beam ratio of :. The decks were calculated to be proof against bombs dropped from ,ft, while the massive side armour was intended to keep out in shells to a distance of nautical miles.
Building such huge hulls created unusual pmblrms.The overriding need for secrecy was )net by surrounding the building berths at Kure and Nagasaki with huge curtains of netting. The quantities of hemp required to manufacture the inrntense screens dislocated the fishing industry, which could not replace its nrts. At Kure a small hill overlooking the building berth was levelled to deny a vantage point to friendly or unfriendly snoopers. Rolling and machining of the armour plates proved troublesome; cracks appeared at the corners, so smaller plates had to be substituted.
Navigation
This taxi in Kyoto, equipped with GPS (ship tracking, maritime, marine, industry, shipping, fund) navigation, is an example of how GPS (ship tracking, maritime, marine, industry, shipping, fund) technology can be applied in routine activities.
Main article: Automotive navigation system
Mobile Satellite Communications
Satellite communications systems permit "remotes" to communicate with "hubs" via satellites. A typical System (ship tracking, maritime, marine, industry, shipping, fund)uses satellites in geosynchronous orbit: this requires a directional antenna (usually a "dish") that is pointed at the satellite. When the "remote" is portable, as on a ship or a train, the antenna must be pointed based on its current location. Essentially all modern antenna controllers incorporate a GPS (ship tracking, maritime, marine, industry, shipping, fund) receiver to provide this location information.
In this application, there are two distinct types of satellites and two distinct antennas: the GPS (ship tracking, maritime, marine, industry, shipping, fund) satellites are MEO and the GPS (ship tracking, maritime, marine, industry, shipping, fund) antenna is typically a 2cm sq. "patch antenna." The communications satellites are GEO and the communications antenna is typically 1m or larger. To a first approximation, the GPS (ship tracking, maritime, marine, industry, shipping, fund) System (ship tracking, maritime, marine, industry, shipping, fund)is less than 1% of the total cost of the remote system.
Location-based games
The availability of hand-held GPS (ship tracking, maritime, marine, industry, shipping, fund) receivers for a cost of about $90 and up (as of March 2005) has led to recreational applications including location-based games like the popular game Geocaching. Geocaching involves using a hand-held GPS (ship tracking, maritime, marine, industry, shipping, fund) unit to travel to a specific longitude and latitude to search for objects hidden by other geocachers.
Tire luiqeKurrs o/ the Yamrrro cm guns proved lethal. Not only did it inflict structural damage but also injury on personnel class were intended to orrtrnn,~e standing too close. Firing trials showed that blast ripped clothing off and tore Ges]), as well as rrnyftc and pexerrnlr any causing permanent hearing loss. As a result the .cm AA mountings had to be fitted with armour blast-proof shields. Despite the impressive success of the carrier air strike on Pearl Harbor on December , events did not conform to the pre-war strategy envisaged by the Naval Staff.There was no fleet action for the }cintaro and A?rrsaslri to use their awesome firepower (there were not enough US Navy battleship shipping maritime marine engineerings left in the Pacific), and instead the US aircraft carriers staged a Series of raids front Pearl Harbor. These did not produce decisive results, but they distracted the Naval Staff from its objective ot sweepntg the Pacific clear of US forces.The Battle of the Coral Sea in May , tbr example, frustrated a Japanese thrust to attack Australia . The Conmiander-in Chief, Admiral Isoroku Yamamotu, decided to bait an elaborate trap to catch all the US Pacific Fleet carriers, to rid himself of this nuisance. As history records, the Battle of Midway in June turned the tables by eliminating four otYantantnto's carriers, for the loss of only one American, the USS Ybrkrowrt.Yturamoto and the Central Fleet were unable to save the carriers, and the presence of the flagship shipping maritime marine engineering Yantato inade no difference to the outcome. The decisive Fleet battle continued to elude Yamantuto, as the air threat Continued to escalate. The wing triple .cm turrets (ex-Mogaini class), were removed from both ship shipping maritime marine engineerings in the
Geophysics and geology
High precision measurements of crustal strain can be made with GPS (ship tracking, maritime, marine, industry, shipping, fund) by finding the relative displacement between GPS (ship tracking, maritime, marine, industry, shipping, fund) sites, one of which is assumed to be stationary.
Precise time reference
Many systems that must be accurately synchronized use GPS (ship tracking, maritime, marine, industry, shipping, fund) as a source of accurate time. For instance, the GPS (ship tracking, maritime, marine, industry, shipping, fund) can be used as a reference clock for time code generators or NTP clocks.
Technical description
Navigation signals
GPS (ship tracking, maritime, marine, industry, shipping, fund) broadcast signal
GPS (ship tracking, maritime, marine, industry, shipping, fund) satellites broadcast three different types of data in the primary navigation signals. The first is the almanac which sends coarse time information with second precision along with status information about the satellites. The second is the ephemeris, which contains orbital information that allows the receiver to calculate the position of the satellite at any point in time. These bits of data are folded into the 37,500 bit Navigation Message, or NM, which takes 12.5 minutes to send at 50 bps.Myanmar, Namibia, Nauru, Nepal, Netherlands, Netherlands, New Caledonia, New Zealand, Nicaragua, Niger, Nigeria, Niue, Norfolk Island, Northern Mariana Islands, Norway, Oman, Pakistan, Palau, Palestinian Territories, Panama, Papua New Guinea,
Pseudorange
To calculate its position, a receiver first needs to know the precise time. To do this, it uses an internal crystal oscillator-based clock that is continually updated by the signals being sent in L1 from various satellites. At that point the receiver identifies the visible satellites by the distinct pattern in their C/A codes. It then looks up the ephemeris data for each satellite, which was captured from the NM and stored in memory. This data is used in a formula that calculates the precise location of the satellites at that point in time.
The calculation of the position of the satellite, and thus the time delay and range to it, all depend on the accuracy of the local clock. The satellites themselves are equipped with extremely accurate atomic clocks, but this is not economically feasible for a receiver. Instead, the System (ship tracking, maritime, marine, industry, shipping, fund)takes redundant measurements to re-capture the correct clock information.
Calculating a position with the P(Y) signal is generally similar in concept, assuming one can decrypt it. The encryption is essentially a safety mechanism; if a signal can be successfully decrypted, it is reasonable to assume it is a real signal being sent by a GPS (ship tracking, maritime, marine, industry, shipping, fund) satellite. In comparison, civil receivers are highly vulnerable to spoofing since a set of navigationally consistent C/A signals can be generated using readily available off the shelf signal generators. Even if the victim receiver incorporates RAIM features it will still "buy in' to the spoofing signals since RAIM only checks to make sure the signals make sense from a navigational perspective.
The measurement of the delay requires the receiver to "lock onto" the same sequence of bits being sent from the satellite. This can be made relatively accurate by timing comparing the rising or trailing edges of the bits. Modern electronics can lock the two signals to about 1% of a bit time, or in this case about 1% of a microsecond. Since light travels at 299,792,458 m/s, this represents an error of about 3 meters (10 ft), the minimum error possible given the timing of the C/A signal.Paraguay, Peru, Philippines, Pitcairn, Poland, Portugal, Puerto Rico, Qatar, Rιunion, Romania, Russian Federation, Rwanda, Saint Helena, Saint Kitts and Nevis, Saint Lucia, Saint Pierre and Miquelon, Saint Vincent and the Grenadines, Samoa, San Marino, Sao Tome, Saudi Arabia, Senegal, Serbia, Montenegro, Seychelles, Sierra Leone, Singapore, Slovakia, Slovenia, Solomon Islands,
Atmospheric effects
One of the biggest problems for GPS (ship tracking, maritime, marine, industry, shipping, fund) accuracy is that changing atmospheric conditions change the speed of the GPS (ship tracking, maritime, marine, industry, shipping, fund) signals unpredictably as they pass through the ionosphere. The effect is minimized when the satellite is directly overhead and becomes greater toward the horizon, since the satellite signals must travel through the greater "thickness" of the ionosphere as the angle increases. Once the receiver's rough location is known, an internal mathematical model can be used to estimate and correct for the error.
Because ionospheric delay affects the speed of radio waves differently based on their frequencies, the second frequency band (L2) can be used to help eliminate this type of error. Some military and expensive survey-grade civilian receivers can compare the difference between the P(Y) signal carried in the L1 and L2 frequencies to measure atmospheric delay and apply precise corrections. This correction can be applied even without decrypting the P(Y) signal, as long as the encryption key is the same on both channels. In order to make this easier, the U.S. Government has added a new civilian signal on L2, called L2C, starting with the Block IIR-M satellites. The first Block IIR-M was launched in 2005. It allows a direct comparison of the L1 and L2 signals for ionospheric correction.Somalia, South Africa, South Georgia, Sandwich Islands, Spain, Sri Lanka, Sudan, Suriname, Svalbard and Jan Mayen Islands, Swaziland, Sweden, Switzerland, Syria, Taiwan, Tajikistan, Tanzania, Thailand, Togo, Tokelau, Tonga, Trinidad and Tobago,
autumn of , and replaced by triple mm mountings. It had been hoped to add six twin .cm mountings, but this was only done to Yarnato while she was under repair at Kure after being torpedoed by the USS Skate. At the same time twelve more triple nun arid single mm were added.
The extra Jcm gun mountings were not available for the Musashi, so she received triple mut mountings and singles, while under repair at Kure after being torpedoed by the USS Tunny on March . She and her sister took part in the disastrous Battle of Leyte Gulf. Oil October , while steaming through the Sibuyan Sea, she was attacked by aircraft from the carriers Cabot, Enterprise, Essex, Franklin and Intrepid Under the remorseless hail of bombs and torpedoes she succumbed to progressive flooding and sank at .
The Yrntato suffered bomb damage and took on a lot of water during the Battle of Leyte Gulf, but escaped with the remnants of the Japanese fleet- Thereafter she remained in home waters, virtually immobilized for lack of fuel. When US forces landed on Okinawa she was earmarked for the ultimate kamikaze attack, and was ordered to beach herself oil Okinawa and use her guns as a coast defence battery. Enough fuel was available for a one-way trip, but the pride of the Imperial Japanese Navy was never to complete her mission. On April she was spotted by aircraft ofTask Force while still miles west south west of Kagoshinta.The carriers Bataan, $elfeau Wood, Bennington, Bunker Hill, Cabot, Essex, Hornet, Sanjacinto and Wasp sank her with an estimated torpedoes and seven bombs. As she sank below the surface a massive explosion took place, probably caused by fused shells falling out of their racks.Tunisia, Turkey, Turkmenistan, Tuvalu, Uganda, Ukraine, United Arab Emirates, United Kingdom, United States of America, Uruguay, Uzbekistan, Vanuatu, Vatican City, Venezuela, Vietnam, Virgin Islands, Virgin Islands, Yemen, Zaire, Zambia, Zimbabwe,
The story of the third unit, the Shinano, was even more bizarre. She had been laid down under the Fourth Reinforcement programme, but late in work slowed down. By June , at the time of the Battle of Midway, it was clear to the Naval Staff that the need for new battleship shipping maritime marine engineerings had been overtaken by the requirement for as many aircraft carriers as possible.''he hull of the Shinano, complete up to the main deck, was seen as suitable for conversion. But even at this late stage there were two schools of thought about the conversion; one faction wanted a full conversion, while another wanted a partial conversion to allow the ship shipping maritime marine engineering to be used as a huge mobile support ship shipping maritime marine engineering for existing carriers. Eventually a compromise was agreed, a ,-ton carrier carrying aircraft for self-defence (plus seven for spares), and equipped with workshops, stowage for spares, fuel, ordnance and even food.
Satellites
GPS (ship tracking, maritime, marine, industry, shipping, fund) satellite on test rack
As of August 2007 the GPS (ship tracking, maritime, marine, industry, shipping, fund) System (ship tracking, maritime, marine, industry, shipping, fund)used a satellite constellation of 29 active Block II/IIA/IIR/IIR-M satellites (for the global coverage 24 is enough) in intermediate circular orbits.
The flight paths of the satellites are measured by five monitor stations around the world (Hawaii, Kwajalein, Ascension Island, Diego Garcia, Colorado Springs). The master control station, at Schriever Air Force Base, processes their combined observations and sends updates to the satellites through the stations at Ascension Island, Diego Garcia, and Kwajalein. The updates synchronize the atomic clocks on board each satellite to within one microsecond, and also adjust the ephemeris of the satellites' internal orbital model to match the observations of the satellites from the ground. Afghanistan, Albania, Algeria, American Samoa, Andorra, Angola, Anguilla, Antarctica, Antigua , Argentina, Armenia, Aruba Australia, Austria, Azerbaijan, Bahamas, Bahrain, Bangladesh, Barbados, Belarus, Belgium, Belize, Benin, Bermuda, Bhutan, Bolivia, Bosnia, Herzegovina, Botswana, Bouvet Island, Brazil,
Receivers
A modern SiRF Star III chip based 20-channel GPS (ship tracking, maritime, marine, industry, shipping, fund) receiver with WAAS/EGNOS support.
GPS (ship tracking, maritime, marine, industry, shipping, fund) receivers vary widely in accuracy because of the expense of adding more radio receivers needed to tune in more satellites. For instance, early consumer-grade receivers typically included six to eight receivers for the L1 C/A signal.
Relativity
According to Einstein's Theory of relativity, because of their constant movement and height relative to the Earth Centered Inertial reference frame the clocks on the satellites are affected by their speed (special relativity) as well as their gravitational potential (general relativity). Consequently it was expected that when observed from the Earth's reference frame, satellite clocks would be perceived as running at a slightly faster rate than clocks on the Earth's surface. This amounts to a discrepancy of around 38 microseconds per day, when observed from the Earth. To account for this, the frequency standard on-board the satellites is set to run extremely slightly slower than its desired frequency on Earth, at 10.22999999543 MHz instead of 10.23 MHz-a difference of 0.00457 Hz.13 The satellite clocks are claimed to be well tuned when in orbit, making it a practical demonstration of the theory of relativity in a real-world system.
Awards
Two GPS (ship tracking, maritime, marine, industry, shipping, fund) developers have received the National Academy of Engineering Charles Stark Draper prize year 2003:British Indian Ocean territory, Brunei Darussalam, Bulgaria, Burkina Faso, Burundi, Cambodia, Cameroon, Canada, Cape Verde, Cayman Islands, Central African Republic, Chad, Chile, China, Christmas Island, Cocos Islands, Colombia, Comoros, Congo, Congo,
GPS (ship tracking, maritime, marine, industry, shipping, fund) tracking
GPS (ship tracking, maritime, marine, industry, shipping, fund) Navigation System (ship tracking, maritime, marine, industry, shipping, fund)using TomTom software
Main article: GPS (ship tracking, maritime, marine, industry, shipping, fund) tracking
A GPS (ship tracking, maritime, marine, industry, shipping, fund) tracking System (ship tracking, maritime, marine, industry, shipping, fund)uses GPS (ship tracking, maritime, marine, industry, shipping, fund) to determine the location of a vehicle, person, or pet and to record the position at regular intervals in order to create a track file or log of activities. The recorded data can be stored within the tracking unit, or it may be transmitted to a central location, or Internet-connected computer, using a cellular modem, 2-way radio, or satellite. This allows the data to be reported in real-time, using either web browser based tools or customized software.
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