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Translate the words, use them in word combinations
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to detect – detector - detecting
to indicate – indicator - indicating
to survey – surveyor - surveying
to measure - measure - measuring
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Introduction
Surveying is a mean of making relatively large-scale, accurate measurements of the Earth's surfaces. It includes the determination of the measurement data, the reduction and interpretation of the data to usable form, and, conversely, the establishment of relative position and size according to given measurement requirements. Thus, has two similar but opposite functions: (1) the determination of existing relative horizontal and vertical position, such as that used for the process of mapping, and (2) the establishment of marks to control construction or to indicate land boundaries.
Surveying has been an essential element in the development of the human environment for so many centuries that its importance is often forgotten. It is an imperative requirement in the planning and execution of nearly every form of construction. Surveying was essential at the dawn of history, and some of the most significant scientific discoveries could never have been implemented were it not for the contribution of surveying. Its principal modern uses are in the fields of transportation, building, apportionment of land, and communications.
Except for minor details of technique and the use of one or two minor hand-held instruments, surveying is much the same throughout the world. The methods are a reflection of the instruments, manufactured chiefly in Switzerland, Austria, Great Britain, the United States, Japan, and Germany. Instruments made in Japan are similar to those made in the West.
Find equivalents.
1. подобны тем, что сделаны
2. относительно крупномасштабные, точные измерения
3. сферы перевозки, строительства, распределение земли и коммуникационных технологий
4. было необходимо на заре истории
5. процесс создания карт
6. необходимое требование в планировании
Answer the questions.
1. What functions has surveying?
2. What instruments are similar?
3. Why was surveying essential at the dawn of history?
4. What are principal uses of surveying?
Write in Passive.
1. They implemented scientific discoveries with the help of surveying.
Scientific discoveries were implemented with the help of surveying.
2. They manufactured instruments chiefly in Switzerland, Japan and Germany.
3. They gave measurement requirements for establishment of position and size.
4. They forgot the importance of surveying.
5. They indicated land boundaries long time ago.
Translate the text.
History
It is quite probable that surveying had its origin in ancient Egypt. The Great Pyramid of Khufu at Giza was built in 2700 BC, 755 feet long and 480 feet high. Its nearly perfect squareness and north–south orientation affirm the ancient Egyptians' command of surveying.
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Evidence of some form of boundary surveying as early as 1400 BC has been found in the fertile valleys and plains of the Tigris, Euphrates, and Nile rivers. Clay tablets of the Sumerians show records of land measurement and plans of cities and nearby agricultural areas. Boundary stones marking land plots have been preserved.
There is a representation of land measurement on the wall of a tomb at Thebes (1400 BC) showing head and rear chainmen measuring a grainfield with what appears to be a rope with knots or marks at uniform intervals.
There is some evidence that, in addition to a marked cord, wooden rods were used by the Egyptians for distance measurement. They had the groma, which was used to establish right angles. It was made of a horizontal wooden cross pivoted at the middle and supported from above. A plumb bob hung from the end of each of the four arms.
There is no record of any angle-measuring instruments of that time, but there was a level consisting of a vertical wooden A-frame with a plumb bob supported at the peak of the A so that its cord hung past an indicator, or index, on the horizontal bar.
The Greeks used a form of log line for recording the distances run from point to point along the coast while making their slow voyages from the Indus to the Persian Gulf about 325 BC.
The magnetic compass was brought to the West by Arab traders in the 12th century AD.
The astrolabe was introduced by the Greeks in the 2nd century BC. An instrument for measuring the altitudes of stars, or their angle of elevation above the horizon, took the form of a graduated arc suspended from a hand-held cord. A pivoted pointer that moved over the graduations was pointed at the star. The instrument was not used for nautical surveying for several centuries, remaining a scientific aid only.
During their occupation of Egypt, the Romans acquired Egyptian surveying instruments, which they improved slightly and to which they added the water level and the plane table. About 15 BC the Roman architect and engineer Vitruvius mounted a large wheel of known circumference in a small frame, in much the same fashion as the wheel is mounted on a wheelbarrow; when it was pushed along the ground by hand it automatically dropped a pebble into a container at each revolution, giving a measure of the distance traveled. It was, in effect, the first odometer.
In laying out their great road system, the Romans are said to have used the plane table. It consists of a drawing board mounted on a tripod or other stable support and of a straightedge —usually with sights for accurate aim to the objects to be mapped — along which lines are drawn. It was the first device capable of recording or establishing angles. Later adaptations of the plane table had magnetic compasses attached.
Plane tables were in use in Europe in the 16th century, and the principle of graphic triangulation and intersection was practiced by surveyors. In 1615 Willebrord Snell, a Dutch mathematician, measured an arc of meridian by instrumental triangulation.
In 1620 the English mathematician Edmund Gunter developed a surveying chain, which was superseded only by the steel tape in the beginning of the 20th century.
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Find equivalents.
1. весьма вероятно, что геологические изыскания
2. планы городов и близлежащих сельскохозяйственных районов
3. доказательство ведения землемерных работ на стене гробницы
4. нет записей о существовании инструментов для измерения углов того времени
5. был привезен на запад арабскими торговцами
6. оставался только для научных целей
7. большое колесо определенной окружности
Complete the table.
| Device | Inventors | Using |
| boundary stones | ||
| a rope with knots | ||
| groma | ||
| level | ||
| log line | ||
| magnetic compass | ||
| astrolabe | ||
| water level | ||
| plane table | ||
| the first odometer | ||
| surveying chain |
Translate the text.
The theodolite
Though for sketch maps the compass or graphic techniques are acceptable for measuring angles, only the theodolite can assure the accuracy required in the framework needed for precise mapping. The theodolite consists of a telescope pivoted around horizontal and vertical axes so that it can measure both horizontal and vertical angles. These angles are read from circles graduated in degrees and smaller intervals of 10 or 20 minutes. The exact position of the index mark (showing the direction of the line of sight) between two of these graduations is measured on both sides of the circle with the aid of a vernier or a micrometer. The accuracy in modern first-order or geodetic instruments, with five-inch glass circles, is approximately one second of arc, or 1/3,600 of a degree. With such an instrument a sideways movement of the target of one centimeter can be detected at a distance of two kilometres. By repeating the measurement as many as 16 times and averaging the results, horizontal angles can be measured more closely; in geodetic surveying, measurements of all three angles of a triangle are expected to give a sum of 180 degrees within one second of arc.
In the most precise long-distance work, signaling lamps or heliographs reflecting the Sun are used as targets for the theodolite. For less demanding work and work over shorter distances, smaller theodolites with simpler reading systems can be used; targets are commonly striped poles or ranging rods held vertical by an assistant.
An extensive set of these measurements establishes a network of points both on the map, where their positions are plotted by their coordinates, and on the ground, where they are marked by pillars, concrete ground marks, bolts let into the pavement, or wooden pegs of varying degrees of cost and permanence, depending on the importance and accuracy of the framework and the maps to be based on it. Once this framework has been established, the surveyor proceeds to the detail mapping, starting from these ground marks and knowing that their accuracy ensures that the data obtained will fit precisely with similar details obtained elsewhere in the framework.
Find equivalents.
1. может измерять как горизонтальные, так и вертикальные углы
2. усредняя результаты
3. при работе на дальних расстояниях
4. устанавливает сеть точек на карте
5. геодезист приступает к детальному
6. может быть обнаружено на расстоянии
7. их точность обеспечивает, что полученные данные
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Answer the questions.
1. What do a telescope consist of?
2. What does an extensive set of measurements establish?
3. What is the accuracy in modern first-order or geodetic instruments?
4. What is used in the most precise long-distance work?
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