Модуль № „Геодезія і геоінфомаційні системи”
Exercise 1. Read and translate the text.
Text 1. General characteristic of Geodesy
Geodesy is one of the oldest natural sciences which involve the study of the Earth’s shape and its gravity field. It provides the scientific basis of precise surveying navigation, mapping and charting, and studies of the physics and dynamics of the Earth.
The History of Geodesy. Throughout the history the shape of the Earth has been discussed by scientists and philosophers. By 500 B.C. most scholars thought the Earth was completely spherical. The Greek philosopher Aristotle was the first person who calculated the size of the Earth by determining its circumference (the length around the equator).
As technology developed, scientists began to use different techniques to measure distance. The English thought the Earth was oblate or flattened at the poles. It was proved that Newton was right. The earth is flattened into the shape of an oblate sphere.
During the last 100 years, geodesy and its application have advanced tremendously. The 20th century brought space-based technology, making geodetic measurements extremely precise. Today satellites allow scientists to measure changes in the Earth’s surface to the centimeter.
The Elements of Geodesy. The Figure of the Earth. The Earth is nearly spherical with a radius of about 3,963 miles (6,378 km), and its surface is very irregular. Mountains and valleys make actually measuring this surface impossible, because an infinite amount of data would be needed.
To measure the Earth, geodesists use a theoretical mathematical surface called the ellipsoid. Because the ellipsoid exists only in theory and not in real life, it can be completely smooth and doesn’t take any irregularities – such as mountains or valleys into account. The ellipsoid is created by rotating an ellipse around its shorter axis. This matches the real Earth’s shape, because the Earth is slightly flattened at the poles and bulges at the equator. The ellipsoid is only a mathematical concept. Geodesists need to account for the reality of the Earth’s surface. To meet this need, the geoid, a shape that refers to global mean sea level was created although a geoid may seem to be smooth, regular shape but because of variations in gravitational force, the “height” of different parts of geoid is always changing, moving up and down in response to gravity.
Exercise 2. Look through the words and try to remember their meaning:
to involve —поєднувати, містити в собі
to bulge —випинатися
shape —форма
gravity —гравітація
gravitational force —гравітаційна сила
gravity field —гравітаційне поле
spherical —сферичний
circumference —коло, периферія
flattened —сплющений
oblate sphere —сплющена сфера
geodetic measurements —геодезичні вимірювання
satellite —супутник
ellipsoid —еліпсоїд
shorter axis —мала вісь
geoid —геоїд
variation —відхилення
scholar —учений
smooth —гладкий, рівний
precise —точний, визначений, чіткий
Exercise 3. Answer the following questions:
1. What is geodesy as a science?
2. Who was the first person who calculated the size of the Earth by determining its circumference?
3. Why it was proved that Newton was right?
4. What did the 20th century bring?
5. What is the radius of the Earth?
6. What theoretical mathematical surface did the geodesists use to measure the Earth?
7. Why did the geodesists chose geoid?
Exercise 4. Translate the following word combinations:
gravity field, surveying navigation, mapping and charting, different techniques, oblate sphere, making geodetic measurements, real Earth’s shape, mathematical concept, to be flattened at poles, global mean sea level, regular shape, to meet the need.
Exercise 5. Complete the following chart:
Verb |
Noun |
Adjective |
to discuss |
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|
to determine |
|
|
to develop |
|
|
to differ |
|
|
to use |
|
useful |
to measure |
|
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to change |
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to improve |
improvement |
|
Exercise 6. Look through the following verb forms and define the tense, write the infinitive of the verb:
has been discussed, thought, developed, began, was proved, have advanced, would be needed, is created, may seem, is always changing.
Exercise 7. Put verbs in the brackets in the correct form:
1. Throughout the history the shape of the Earth _______ (to be) discussed by scientists and philosophers.
2. By 500 B.C. most scholars_____(to think) the Earth was completely spherical.
3. As technology developed, scientists _______ (to begin) to use different techniques to measure distance.
4. It _________ (to be) proved that Newton was right.
5. During the last 100 years, geodesy and its application____________ (to advance) tremendously.
6. The ellipsoid _______(to be) created by rotating an ellipse around its shorter axis.
7. The ellipsoid _______(to be) only a mathematical concept.
Exercise 8. Read and translate the text.