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Words to be learnt. precisely identify – точно определить

precisely identify – точно определить

by measuring – путем измерения

ongoing maintenance – постоянно ведущиеся эксплуатационные работы

military application – военное применение

troop deployment – расположение войск

recreational – прогулочный, развлекательный, для отдыха

surveyor – наблюдатель

weapon – оружие

commonplace – привычная вещь

emergency roadside assistant – помощь при аварии на дорогах

to span – охватывать, включать

saving – сбережения, спасение

to flag – сигнализировать

hostile – вражеский, неприятельский

howitzer – гаубица

reconnaissance – разведка, рекогносцировка

detonation – взрыв, детонация

to keep track – проследить

turning – хронирование

unmanned monitoring station – автоматическая станция

master control station – ведущая станция контроля

uplinks – спутниковый канал связи


Global Positioning System is a network of satellites that continuously transmit coded information, which makes it possible to precisely identify locations on earth by measuring distance from the satellites. GPS stands for Global Positioning System, and refers to a group of U.S. Department of Defense satellites constantly circling the earth. The satellites transmit very low power radio signals allowing anyone with a GPS receiver to determine their location on Earth.

This remarkable system was not cheap to build, costing the U.S. billions of dollars. Ongoing maintenance, including the launch of replacement satellites, adds to the cost of the system. GPS actually predates the introduction of the personal computer. The designers originally had a military application in mind. The first satellite navigation system, Transit, used by the United States Navy, was first successfully tested in 1960. It used a constellation of five satellites and could provide a navigational fix approximately once per hour. In 1967, the U.S. Navy developed the Timation satellite which proved the ability to place accurate clocks in space, a technology that GPS relies upon. In the 1970s, the ground-based Omega Navigation System, based on phase comparison of signal transmission from pairs of stations, became the first worldwide radio navigation system. The design of

GPS is based partly on similar ground-based radio navigation systems, such as LORAN and the Decca Navigator developed in the early 1940s, and used during World War II. The military applications of GPS span many purposes:

• Navigation: GPS allows soldiers to find objectives in the dark or in unfamiliar territory, and to coordinate the movement of troops and supplies. The GPS-receivers that commanders and soldiers use are respectively called the Commanders Digital Assistant and the Soldier Digital Assistant.

• Target tracking: Various military weapons systems use GPS to track potential ground and air targets before they are flagged as hostile. These weapon systems pass GPS co-ordinates of targets to precision-guided munitions to allow them to engage the targets accurately. Military aircraft, particularly those used in air-to-ground roles use GPS to find targets.

• Missile and projectile guidance: GPS allows accurate targeting of various military weapons including ICBMs, cruise missiles and precision-guided munitions. Artillery projectiles with embedded GPS receivers able to withstand accelerations of 12,000g's or about

117,600 meters/second2 have been developed for use in 155 mm howitzers.

• Search and Rescue: Downed pilots can be located faster if they have a GPS receiver.

• Reconnaissance and Map Creation: The military use GPS extensively to aid mapping and reconnaissance.

• The GPS satellites also carry a set of nuclear detonation detectors consisting of an optical sensor (Y-sensor), an X-ray sensor, a dosimeter, and an electromagnetic pulse (EMP) sensor (W-sensor) which form a major portion of the United States Nuclear Detonation Detection System.

Fortunately, an executive decree in the 1980s made GPS available for civilian use also. Land-based applications are more diverse. The scientific community uses GPS for its precision timing capability and a myriad of other applications. Surveyors use GPS for an increasing portion of their work. GPS offers an incredible cost savings by drastically reducing setup time at the survey site. It also provides amazing accuracy. Basic survey units can offer accuracies down to one meter. More expensive systems can provide accuracies to within a centimeter! Recreational uses of GPS are almost as varied as the number of recreational sports

available. GPS is becoming increasingly popular among hikers, hunters, snowmobilers, mountain bikers, and crosscountry skiers, just to name a few. GPS is rapidly becoming commonplace in automobiles as well. Some basic systems are already in place, providing emergency roadside assistance at the push of a button (by transmitting your current position to a dispatch center).

The NAVSTAR system (the acronym for Navigation Satellite Timing and Ranging, the official U.S. Department of Defense name for GPS) consists of a space segment (the satellites), a control segment (the ground stations), and a user segment (you and your GPS receiver).The space segment, which consists of at least 24 satellites (21 active plus 3 operating spares) is the heart of the system. The satellites are in what's called a "high orbit" about 12,000 miles above the Earth's surface. Operating at such a high altitude allows the signals to cover a greater area. The satellites are arranged in their orbits so a GPS receiver on earth can always receive from at least four of them at any given time. The "control" segment does what its name implies — it "controls" the GPS satellites by tracking them and then providing them with corrected orbital and clock (time) information. There are five control stations located around the world — four unmanned monitoring stations and one "master control station". The four unmanned receiving stations constantly receive data from the satellites and then send that information to the master control station. The master control station "corrects" the satellite data and, together with two other antenna sites, sends ("uplinks") the information to the GPS satellites. The user segment simply consists of you and your GPS receiver. As mentioned previously, the user segment consists of boaters, pilots, hikers, hunters, the military and anyone else who wants to know where they are, where they have been or where they are going.

Задание I. Выберите правильное утверждение и выучите его наизусть:

1. a) GPS is a network of satellites transmitting coded information to identify locations on Earth

b) GPS is a system of stations for measuring distance from the satellites

c) GPS is a network for monitoring satellite data

2. a) GPS actually predates the introduction of Internet

b) GPS actually predates the introduction of radar technology

c) GPS actually predates the introduction of the personal computer

3. a) The designers of GPS originally had commercial purposes in mind

b) The designers of GPS originally had educational application in mind

c) The designers of GPS originally had a military application in mind

4. a) Military aircraft can’t use GPS to find targets

b) GPS allows soldiers to find commanders

c) Various military weapons systems use GPS to track potential ground and air targets before they are flagged as hostile

5. a) GPS is popular among hikers, hunters, snowmobilers, mountain bikers and cross-country skiers.

b) GPS is not used for recreational uses

c) GPS is commonplace in automobiles in Russia

6. a) The NAVSTAR consists of the satellites

b) The NAVSTAR consists of the ground stations

c) The NAVSTAR consists of a space segment (the satellites), a control segment (the ground stations), and a user segment (you and your receiver)

Задание II. Задайте в группе все возможные виды вопросов, используя предложения, данные в задании I .

Задание III. Выполнив все задания, будьте готовы побеседовать по теме «GPS» на английском языке с группой и с преподавателем

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