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2. Гравіметричні дані використовують в астрономії,
метрології, геодезії, геології, космонавтиці та ін.
3. Основний зміст гравіметрії в геодезії - теорії та методи
визначення зовнішнього поля потенціалу та сили тяжіння Землі

(g) за вимірюваннями на земній поверхні і по астрономо-
геодезичним даними.
4. Наземні гравіметричні спостереження проводяться за

допомогою гравіметрів або акселерометрів.
5. В гравіметричних спостереженнях за допомогою
супутника використовуються, як правило, високоточні
вимірювання його орбіти.

V. SPEAKING

Task 1. Render the main idea of the text.

Gravity Anomalies

Gravity measurements provide values for the acceleration of
gravity at points located on the physical surface of the Earth. Before

these measurements can be used for most geodetic purposes, they
must be converted into gravity anomalies.
Since there are variations in the densities of the Earth's crustal

materials as well as terrain variations, the observed gravity of the
Earth varies irregularly from point to point. As a result the surface
known as the geoid is an irregular figure. As explained earlier, the

distance between the mathematical ellipsoid and the actual geoid is
called the undulation of the geoid. Since the geoid is so irregular,
geoid. undulations cannot be computed directly but must be

determined point by point. Gravity measurements provide the
observational data for these computations.
The word, anomaly, as used in geodesy refers to a deviation from
the normal and can be used either for a single point or to describe a

regional or area effect. To represent an area of the Earth's surface, the
gravity measurements (anomalies) within the area are averaged by
some specialized technique to produce a mean value. This may be

done for areas of different size such as the one degree by one degree
square. To make use of the anomalies, the observed gravity must be
reduced to a common frame of reference, the geoid-mean sea level.
The reductions may take into account the elevation above (or below)

sea level and can account for the mass between the point and sea level,

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