Good day.
Everyone, probably, at school came across, heard about such concepts as longitude and latitude.
Most often this happened in geography lessons.
So, both of these concepts denote an angle. Latitude- this is the angle between the equator, or rather its plane, and the line from this point; longitude this is the angle between the plane of the meridian passing through the given point and the plane of the zero meridian.
Longitudes from 0 to 180 to the east of that same zero meridian are usually called eastern (while they are usually called or considered positive), and to the west - western (they are also called negative).
Latitude and longitude are angles. Together they form coordinates that can be used to find the position of an object on a spherical surface, like the Earth.
Latitude is defined in relation to the equator. That is, the equator is the zero surface. Positive latitude is north latitude up to +90 degrees, and negative latitude is south latitude up to -90 degrees.
Longitude is defined in terms of meridians. There is a main meridian, from which the longitude begins - this is Greenwich. All meridians to the east are negative longitude up to -180 degrees, and those to the west are positive longitudes up to + 180 degrees.
Latitude and longitude are geographic coordinates, conditional lines on the surface of the globe.
Latitude is a conditional horizontal line (parallel), and longitude is a vertical line. The latitude reference point starts from the equator. This is zero latitude. Latitudes from the equator to the North Pole are called North (N or N) from 0 to 90, from the Equator to the South Pole - South (S or S).
The reference point for longitude is the Greenwich meridian. This is zero longitude. The longitude going from Greenwich towards the east (towards Japan) is called Eastern longitude (E or E), from Greenwich to the west (towards America) - Western (W or W)
Each latitude and longitude is measured in degrees, each degree is divided into minutes, each minute into seconds. 1 degree = 60 minutes, 1 minute = 60 seconds. These are geometric and astronomical units of measurement.
Each degree, each minute and each second is equal to a certain distance, which changes as you approach the poles: the distance of each degree of latitude increases, and each degree of longitude decreases. All points converge at the poles geographical coordinates, so there is only latitude (no longitude): the North Pole is 9000? 00? North latitude, the South Pole is 9000? 00? South latitude.
Of course, everything will depend on the meaning of the word. After all, it can be the breadth of the soul and the length of clothes. But, we take as a basis all the same geographical concepts. In order not to delve into specific and abstruse terminology, I will try to explain these concepts as simply as possible. After all, it is an accessible explanation that helps to remember information for a long time. I remember back in school we were told to imagine ourselves as travelers on a ship. And in order to understand where our ship is, we must learn to calculate latitude and longitude. To understand our location in relation to the North and South Poles, we need latitude.
Longitude is the dihedral angle between the prime (Greenwich) meridian and the local meridian. Longitudes are counted from 0 to 180, from the Greenwich meridian. In general, longitude and latitude are the data necessary to determine a point in space, in a plane, from geodetic latitude and longitude, a transition is made to flat coordinates in the Gauss-Mercator projection to draw up topographic plans for sites. Longitude and latitude are geodetic, astronomical, depending on whether what coordinate system are you considering?
Longitude and latitude are used to determine a point on the earth's surface. Latitude is the distance from a certain point to the equator, and longitude is the distance to the zero point of the meridian, or Greenwich. This distance is indicated in degrees, minutes and seconds.
Latitude and longitude are coordinates that can be used to locate an object on the surface of our planet or some other celestial body. Longitude can be east or west. Latitude can be determined using such devices as: the gnomon is an ancient astronomical instrument and the sextant is a measuring, navigational instrument.
To determine latitude and longitude, modern satellite navigation systems such as GPS and GLONASS are used. Latitude and longitude are measured:
It is known from school geography that geographic coordinates are used to determine the position of the Earth's points on an ellipsoid (ball). The initial planes in the system of geographical coordinates are the planes of the initial meridian and the equator, and the coordinates angular values: longitude and latitude of the point. Determining the position of a point using latitudes and longitudes was introduced by Hipparchus in the 2nd century BC. BC e. Geographic latitude point is called corner between the equatorial plane and the normal (plumb line) drawn from the given point. Geographic longitude dot it dihedral angle between the plane of the initial (zero Greenwich) meridian and the plane of the meridian passing through the given point.
Longitude and latitude are concepts used in the designation of geographic coordinates.
For example, they say: the ship is at 35 degrees north latitude and 28 degrees east longitude.
How is this to be understood?
To understand, take a globe, touch your finger anywhere on the equator. Then spin the globe without removing your finger. By turning the globe, you change the position of your finger in longitude.
In the city of Greenwich there is a point where the longitude is zero degrees. This is the point through which the prime meridian passes.
Everything to the right on the map is called east longitude, and everything to the left is called west. You can also say just longitude, then the offset to the west or east will be determined by the sign of the angle. If the angle is negative, then the offset is to the west, and if positive - to the east. What is an angle? The angle is the angle between point A with X coordinates at the Greenwich level and Y coordinates at the equator level, point O located in the center of the planet and point B with X coordinates of the desired point and Y coordinates at the equator level.
Latitude is about the same, only it is plotted vertically, that is, perpendicular to longitude. What is above the equator is the north latitude, and what is below is the south. Or just the latitude, then the decrease in the angle goes down (negative angles), and the increase goes up.
Here is the diagram:
Latitude and longitude are purely geographical indicators that are familiar to all schoolchildren. Use latitude and longitude to compile the coordinates of the location of an object.
And now in more detail separately on each concept:
1) Here is what is meant by latitude:
2) This is what is meant by longitude.
It is possible to determine the location of a point on the planet Earth, as well as on any other planet of a spherical shape, using geographical coordinates - latitude and longitude. Right-angled intersections of circles and arcs create a corresponding grid, which makes it possible to uniquely determine the coordinates. illustrative example- an ordinary school globe lined with horizontal circles and vertical arcs. How to use the globe will be described below.
This system is measured in degrees (degree angle). The angle is calculated strictly from the center of the sphere to a point on the surface. Relative to the axis, the degree of the angle of latitude is calculated vertically, longitude - horizontally. To calculate the exact coordinates, there are special formulas, where one more value is often found - the height, which serves mainly to represent three-dimensional space and allows you to make calculations to determine the position of a point relative to sea level.
The earth's sphere is divided by an imaginary horizontal line into two equal parts of the world - the northern and southern hemispheres - into the positive and negative poles, respectively. This is how the definitions of northern and southern latitudes are introduced. Latitude is represented as circles parallel to the equator, called parallels. The equator itself with a value of 0 degrees is the starting point for measurements. The closer the parallel is to the upper or lower pole, the smaller its diameter and the higher or lower the angular degree. For example, the city of Moscow is located at 55 degrees north latitude, which determines the location of the capital as approximately equidistant from both the equator and the north pole.
Meridian - the so-called longitude, represented as a vertical arc strictly perpendicular to the circles of the parallel. The sphere is divided into 360 meridians. The starting point is the zero meridian (0 degrees), the arcs of which pass vertically through the points of the north and south poles and spread in east and west directions. This defines the angle of longitude from 0 to 180 degrees, calculated from the center to the extreme points to the east or south.
Unlike latitude, which is based on the equatorial line, any meridian can be zero. But for convenience, namely the convenience of counting time, the Greenwich meridian was determined.
Latitude and longitude allow you to assign to a particular place on the planet an exact geographical address, measured in degrees. Degrees, in turn, are divided into smaller units, such as minutes and seconds. Each degree is divided into 60 parts (minutes), and each minute is divided into 60 seconds. On the example of Moscow, the record looks like this: 55° 45′ 7″ N, 37° 36′ 56″ E or 55 degrees, 45 minutes, 7 seconds north latitude and 37 degrees, 36 minutes, 56 seconds south longitude.
The interval between the meridians is 15 degrees and about 111 km along the equator - this is the distance the Earth rotates in one hour. It takes 24 hours for a full turn, which is a day.
The model of the Earth is accurately reproduced on a globe with a realistic rendering of all continents, seas and oceans. As auxiliary lines, parallels and meridians are drawn on the map of the globe. Almost any globe has in its design a sickle-shaped meridian, which is installed on the base and serves as an auxiliary measure.
The meridian arc is equipped with a special degree scale, which determines the latitude. Longitude can be found using another scale - a hoop, horizontally installed at the level of the equator. Marking the desired place with your finger and rotating the globe around its axis to the auxiliary arc, we fix the latitude value (depending on the location of the object, it will turn out to be either north or south). Then we mark the data of the equator scale at the place of its intersection with the meridian arc and determine the longitude. To find out whether it is east or south longitude, you can only relative to the zero meridian.
In Chapter 1, it was noted that the Earth has the shape of a spheroid, that is, an oblate ball. Since the terrestrial spheroid differs very little from a sphere, this spheroid is usually called the globe. The earth rotates around an imaginary axis. The points of intersection of an imaginary axis with the globe are called poles. north geographic pole
(PN) is considered to be the one from which the Earth's own rotation is seen counterclockwise. south geographic pole
(PS) is the pole opposite to the north.
If we mentally cut the globe with a plane passing through the axis (parallel to the axis) of the Earth's rotation, we get an imaginary plane, which is called meridian plane
. The line of intersection of this plane with the earth's surface is called geographic (or true) meridian
.
plane perpendicular to earth's axis and passing through the center of the globe is called equatorial plane
, and the line of intersection of this plane with the earth's surface - equator
.
If you mentally cross the globe with planes parallel to the equator, then circles are obtained on the surface of the Earth, which are called parallels
.
Parallels and meridians plotted on globes and maps make up degree
grid
(Fig. 3.1). The degree grid makes it possible to determine the position of any point on the earth's surface.
For the initial meridian in the preparation of topographic maps taken Greenwich astronomical meridian
passing through the former Greenwich Observatory (near London from 1675 - 1953). Currently, the buildings of the Greenwich Observatory house a museum of astronomical and navigational instruments. The modern Prime Meridian passes through Hirstmonceau Castle 102.5 meters (5.31 seconds) east of the Greenwich Astronomical Meridian. The modern prime meridian is used for satellite navigation.
Rice. 3.1. Degree grid of the earth's surface
Coordinates
- angular or linear quantities that determine the position of a point on a plane, surface or in space. To determine coordinates on the earth's surface, a point is projected by a plumb line onto an ellipsoid. To determine the position of horizontal projections of a terrain point in topography, systems are used geographical
, rectangular
and polar
coordinates
.
Geographical coordinates
determine the position of a point relative to the earth's equator and one of the meridians, taken as the initial one. Geographic coordinates may be derived from astronomical observations or geodetic measurements. In the first case they are called astronomical
, in the second - geodetic
. For astronomical observations, the projection of points onto the surface is carried out by plumb lines, for geodetic measurements - by normals, therefore the values of astronomical and geodetic geographical coordinates are somewhat different. To create small scale geographical maps the compression of the Earth is neglected, and the ellipsoid of revolution is taken as a sphere. In this case, the geographic coordinates will be spherical
.
Latitude
- angular value that determines the position of a point on Earth in the direction from the equator (0º) to the North Pole (+90º) or South Pole (-90º). Latitude is measured by the central angle in the meridian plane of a given point. On globes and maps, latitude is shown using parallels.
Rice. 3.2. Geographic latitude
Longitude - angular value that determines the position of a point on Earth in the West-East direction from the Greenwich meridian. Longitudes are counted from 0 to 180 °, to the east - with a plus sign, to the west - with a minus sign. On globes and maps, latitude is shown using meridians.
Rice. 3.3. Geographic longitude
spherical geographic coordinates called the angular quantities (latitude and longitude) that determine the position of terrain points on the surface of the earth's sphere relative to the plane of the equator and the initial meridian.
spherical latitude (φ) call the angle between the radius vector (the line connecting the center of the sphere and a given point) and the equatorial plane.
spherical longitude (λ) is the angle between the zero meridian plane and the meridian plane of the given point (the plane passes through the given point and the axis of rotation).
Rice. 3.4. Geographic spherical coordinate system
In the practice of topography, a sphere with a radius R = 6371 is used km, whose surface is equal to the surface of the ellipsoid. On such a sphere, the arc length of the great circle is 1 minute (1852 m) called nautical mile.
Astronomical geographical
coordinates
are latitude and longitude, which determine the position of points on geoid surface
relative to the plane of the equator and the plane of one of the meridians, taken as the initial one (Fig. 3.5).
Astronomical latitude (φ) called the angle formed by a plumb line passing through a given point and a plane perpendicular to the axis of rotation of the Earth.
Plane of the astronomical meridian
- a plane passing through a plumb line at a given point and parallel to the axis of rotation of the Earth.
astronomical meridian
- the line of intersection of the surface of the geoid with the plane of the astronomical meridian.
Astronomical longitude (λ) called the dihedral angle between the plane of the astronomical meridian passing through a given point, and the plane of the Greenwich meridian, taken as the initial one.
Rice. 3.5. Astronomical latitude (φ) and astronomical longitude (λ)
AT geodetic geographic coordinate system
for the surface on which the positions of the points are found, the surface is taken reference
-ellipsoid
. The position of a point on the surface of the reference ellipsoid is determined by two angular values - the geodetic latitude (AT) and geodetic longitude (L).
Plane of the geodesic meridian
- a plane passing through the normal to the surface of the earth's ellipsoid at a given point and parallel to its minor axis.
geodetic meridian
- the line along which the plane of the geodesic meridian intersects the surface of the ellipsoid.
Geodetic parallel
-
the line of intersection of the surface of an ellipsoid by a plane passing through a given point and perpendicular to the minor axis.
Geodetic latitude (AT)- the angle formed by the normal to the surface of the earth's ellipsoid at a given point and the plane of the equator.
Geodetic longitude (L)- dihedral angle between the plane of the geodesic meridian of the given point and the plane of the initial geodesic meridian.
Rice. 3.6. Geodetic latitude (B) and geodetic longitude (L)
Topographic maps are printed in separate sheets, the sizes of which are set for each scale. The side frames of the sheets are the meridians, and the upper and lower frames are the parallels.
. (Fig. 3.7). Consequently, geographic coordinates can be determined by the side frames of the topographic map
. On all maps, the top frame always faces north.
Geographic latitude and longitude are signed in the corners of each sheet of the map. On maps of the Western Hemisphere in the northwest corner of the frame of each sheet to the right of the value the longitudes of the meridian place the inscription: "West of Greenwich."
On maps of scales 1: 25,000 - 1: 200,000, the sides of the frames are divided into segments equal to 1 ′ (one minute, Fig. 3.7). These segments are shaded through one and divided by dots (except for the map at a scale of 1: 200,000) into parts of 10 "(ten seconds). On each sheet, maps of scales 1: 50,000 and 1: 100,000 show, in addition, the intersection of the middle meridian and the middle parallel with digitization in degrees and minutes, and along the inner frame - outputs of minute divisions with strokes 2 - 3 mm long.This allows, if necessary, to draw parallels and meridians on a map glued from several sheets.
Rice. 3.7. Side frames of the card
When compiling maps of scales 1: 500,000 and 1: 1,000,000, a cartographic grid of parallels and meridians is applied to them. Parallels are drawn, respectively, through 20′ and 40 "(minutes), and meridians - through 30" and 1 °.
The geographical coordinates of a point are determined from the nearest southern parallel and from the nearest western meridian, the latitude and longitude of which are known. For example, for a map with a scale of 1: 50,000 "ZAGORYANI", the nearest parallel located to the south of a given point will be the parallel 54º40′ N, and the nearest meridian located to the west of the point will be the meridian 18º00′ E. (Fig. 3.7).
Rice. 3.8. Determination of geographical coordinates
To determine the latitude of a given point, you must:
To determine the longitude of a given point, you must:
note
to the fact that this method determining the longitude of a given point for maps at a scale of 1:50,000 and smaller has an error due to the convergence of the meridians that limit the topographic map from the east and west. The north side of the frame will be shorter than the south side. Therefore, the discrepancies between the measurements of longitude on the northern and southern frames may differ by several seconds. To achieve high precision in the measurement results, it is necessary to determine the longitude on both the south and north sides of the frame, and then interpolate.
To improve the accuracy of determining geographic coordinates, you can use graphic method. To do this, it is necessary to connect with straight lines the nearest ten-second divisions of the same name to the point in latitude to the south of the point and in longitude to the west of it. Then determine the dimensions of the segments in latitude and longitude from the drawn lines to the position of the point and summarize them, respectively, with the latitude and longitude of the drawn lines.
The accuracy of determining geographical coordinates on maps of scales 1: 25,000 - 1: 200,000 is 2" and 10", respectively.
polar coordinates are called the angular and linear quantities that determine the position of a point on the plane relative to the origin, taken as a pole ( O), and the polar axis ( OS) (Fig. 3.1).
The location of any point ( M) is determined by the position angle ( α ), counted from the polar axis to the direction to the determined point, and the distance (horizontal distance - the projection of the terrain line on the horizontal plane) from the pole to this point ( D). Polar angles are usually measured from the polar axis in a clockwise direction.
Rice. 3.9. Polar coordinate system
For the polar axis can be taken: the true meridian, the magnetic meridian, the vertical line of the grid, the direction to any landmark.
Bipolar coordinates call two angular or two linear quantities that determine the location of a point on a plane relative to two starting points (poles O 1 and O 2 rice. 3.10).
The position of any point is determined by two coordinates. These coordinates can be either two position angles ( α 1 and α 2 rice. 3.10), or two distances from the poles to the determined point ( D 1 and D 2 rice. 3.11).
Rice. 3.10. Determining the location of a point at two angles (α 1 and α 2 )
Rice. 3.11. Determining the location of a point by two distances
In a bipolar coordinate system, the position of the poles is known, i.e. the distance between them is known.
3.3. POINT HEIGHT
Previously reviewed plan coordinate systems
, defining the position of any point on the surface of the earth's ellipsoid, or the reference ellipsoid ,
or on the plane. However, these planned coordinate systems do not allow obtaining an unambiguous position of a point on the physical surface of the Earth. Geographical coordinates refer the position of the point to the surface of the reference ellipsoid, polar and bipolar coordinates refer the position of the point to the plane. And all these definitions have nothing to do with the physical surface of the Earth, which is more interesting for a geographer than a reference ellipsoid.
Thus, the planned coordinate systems do not make it possible to unambiguously determine the position of a given point. It is necessary to somehow define your position, at least with the words “above”, “below”. Just about what? For getting complete information about the position of a point on the physical surface of the Earth, the third coordinate is used - height
.
Therefore, it becomes necessary to consider the third coordinate system - height system
.
The distance along a plumb line from the level surface to a point on the physical surface of the Earth is called height.
There are heights absolute if they are counted from the level surface of the Earth, and relative (conditional ) if they are counted from an arbitrary level surface. Usually, the level of the ocean or the open sea in a calm state is taken as the origin of absolute heights. In Russia and Ukraine, the absolute heights are taken as the origin zero of the Kronstadt footstock.
Footstock- a rail with divisions, fixed vertically on the shore so that it is possible to determine the position of the surface of the water in a calm state by it.
Kronstadt footstock- a line on a copper plate (board) mounted in the granite abutment of the Blue Bridge of the Obvodny Canal in Kronstadt.
The first footstock was installed during the reign of Peter the Great, and since 1703 regular observations of the level of the Baltic Sea began. Soon the footstock was destroyed, and only from 1825 (and up to the present time) regular observations were resumed. In 1840, hydrographer M.F. Reinecke calculated the average height of the Baltic Sea level and recorded it on the granite abutment of the bridge in the form of a deep horizontal line. Since 1872, this feature has been taken as a zero mark when calculating the heights of all points on the territory Russian state. The Kronstadt footstock was repeatedly modified, however, the position of its main mark was kept the same during design changes, i.e. determined in 1840
After the collapse Soviet Union Ukrainian surveyors did not begin to invent their own national system of heights, and currently in Ukraine it is still used Baltic height system.
It should be noted that in each necessary do not measure directly from the level of the Baltic Sea. There are special points on the ground, the heights of which were previously determined in the Baltic system of heights. These points are called benchmarks
.
Absolute heights H can be positive (for points above the Baltic Sea level) and negative (for points below the Baltic Sea level).
The difference between the absolute heights of two points is called relative
tall
or excess
(h):
h =H BUT-H AT
.
The excess of one point over another can also be positive and negative. If the absolute height of the point BUT greater than the absolute height of the point AT, i.e. is above the point AT, then the excess of the point BUT over the dot AT will be positive, and vice versa, exceeding the point AT over the dot BUT- negative.
Example. Absolute heights of points BUT and AT: H BUT
= +124,78 m; H AT
= +87,45 m. Find Mutual Exceedances of Points BUT and AT.
Solution. Exceeding point BUT over the dot AT
h A(B)
= +124,78 - (+87,45) = +37,33 m.
Exceeding point AT over the dot BUT
h B(A)
= +87,45 - (+124,78) = -37,33 m.
Example. Point absolute height BUT is equal to H BUT
= +124,78 m. Exceeding point FROM over the dot BUT equals h C(A)
= -165,06 m. Find the absolute height of a point FROM.
Solution. Point absolute height FROM is equal to
H FROM
= H BUT
+ h C(A)
= +124,78 + (-165,06) = - 40,28 m.
The numerical value of the height is called the elevation of the point
(absolute or conditional).
For example, H BUT =
528.752 m - absolute mark of the point BUT; N" AT
\u003d 28.752 m - conditional elevation of the point AT
.
Rice. 3.12. Heights of points on the earth's surface
To move from conditional to absolute heights and vice versa, it is necessary to know the distance from the main level surface to the conditional one.
Video
Meridians, parallels, latitudes and longitudes
Determining the position of points on the earth's surface
Questions and tasks for self-control
Geographic latitude φ is the angle between plumb line at a given point and the plane of the equator, counted from 0 to 90 ° on both sides of the equator.
The term "plumb line" means the direction to the center of gravity ("astronomical latitude") or perpendicular to the surface at a given point ("geodetic latitude"). In the latter case, the "surface" is usually understood as the surface of the ellipsoid approximating the shape of the Earth. In practice, the differences are usually small - for example, in the WGS 84 system used in GPS receivers, the geometric center of the model is assumed to be no more than 2 centimeters from the Earth's center of gravity.
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Synonyms:Antonyms:
LATITUDE- LATITUDE, latitudes, pl. latitude, female 1. only units distraction noun to wide in 3, 4 and 5 digits. Breadth of vision. Breadth of vision. Coverage breadth. 2. One of the quantities that determine the position of a place on the earth's surface: the distance from the equator along the meridian, ... ... Explanatory Dictionary of Ushakov
latitude- s; pl. companies; and. 1. to Wide (5 6 digits). Sh. mind. Sh. soul, nature. Sh. views. Sh. interests. Sh. outlook. Sh. education. 2. Expand. = Width. Sh. rivers. Sh. streets. Sh. at home. 3. One of the geographical coordinates that determine the position of a point on ... ... encyclopedic Dictionary
latitude- breadth, vastness, spaciousness; baggy, infinity, comprehensiveness, range, boundlessness, volume, sweeping, scale, freedom, stowage, appropriateness, breadth, size, scope, scope, sparseness, infinity, ... ... Synonym dictionary
LATITUDE- LATITUDE, s, pl. oty, from, otam, wives. 1. see wide. 2. Geographic coordinate that determines the position of points on the surface of the earth relative to the equator. Southern latitudes. At all latitudes (around the globe, everywhere). Roaring latitudes (about the forties ... ... Explanatory dictionary of Ozhegov
latitude- LATITUDE, s, pl latitudes, from, otam, f Spec. Direction in space, parallel to the equator, one of the geographical coordinates that determine the position of a point on the surface of the earth; distance from the equator along the meridian, expressed in degrees. Northern ... ... Explanatory dictionary of Russian nouns
LATITUDE- LATITUDE, see the article Geographical coordinates ... Modern Encyclopedia
LATITUDE- one of the coordinates in a number of spherical coordinate systems, which determines the position of points on the surface of the Earth, the Sun, planets and on the celestial sphere relative to the equator (ecliptic); see Geographic coordinates, Galactic coordinates, Ecliptic... Big Encyclopedic Dictionary
LATITUDE- LATITUDE, the angle between the plumb line at a given point and the EQUATOR plane, counted from 0° to 90° on both sides of the equator. All latitudes are parallel to the equator, which is considered zero latitude. Each degree of latitude corresponds to 111 km. NORTH… Scientific and technical encyclopedic dictionary
latitude- latitude, s; pl. latitude, latitude, latitude... Russian word stress
Latitude- I f. Wide space, wide space. II well. Vastness, unlimitedness. III. 1. One of the coordinates that determines the position of a point on the earth's surface. 2. Distance from the equator along the meridian, expressed in degrees (from 0 to 90). Explanatory ... ... Modern dictionary Russian language Efremova
Latitude- the angle between the local direction of the zenith and the plane of the equator, counted from 0 to 90 in both directions from the equator. The geographical latitude of points lying in the northern hemisphere (northern latitude) is considered to be positive, the latitude of points in the southern hemisphere is negative. In addition, it is customary to talk about latitudes that are larger in absolute value - as high, and about those close to zero (that is, to the equator) - as about low.
Longitude- the angle between the plane of the meridian passing through the given point, and the plane of the initial zero meridian, from which the longitude is calculated. Now on Earth, the prime meridian is the one that passes through the old observatory in the city of Greenwich, and therefore it is called the Greenwich meridian. Longitudes from 0 to 180 ° east of the zero meridian are called eastern, to the west - western. Eastern longitudes are considered to be positive, western - negative. It should be emphasized that, unlike latitude, for a system of longitudes, the choice of the reference point (zero meridian) is arbitrary and depends only on the agreement. So, in addition to Greenwich, the meridians of the observatories of Paris, Cadiz, Pulkovo (on the territory of the Russian Empire), etc. were previously chosen as zero.
To fully determine the position of a point in three-dimensional space, a third coordinate is needed - height. The distance to the center of the planet is not used in geography: it is convenient only when describing very deep regions of the planet or, on the contrary, when calculating orbits in space.
Within the geographic envelope, it is usually used height above sea level, counted from the level of the "smoothed" surface - the geoid. Such a system of three coordinates turns out to be orthogonal, which simplifies a number of calculations. Altitude above sea level is also convenient in that it is related to atmospheric pressure.
The distance from the earth's surface (up or down) is often used to describe a location, however not serves coordinate due to surface roughness.
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- (Latitude) a geographic coordinate used together with longitude to determine the position of a point on the earth's surface. Represents the angle between the equatorial plane and a plumb line passing through a given point, measured along the meridian from ... Marine Dictionary
See geographic coordinates. Geological dictionary: in 2 volumes. M.: Nedra. Edited by K. N. Paffengolts et al. 1978 ... Geological Encyclopedia
latitude (geographic)- — [[FIATA English Russian Dictionary of Abbreviations of Freight Forwarding and Commercial Terms and Expressions]] Topics freight forwarding services EN Lat.lat.latitude …
geographical latitude- one of two coordinates that determines the position of a point on the Earth's surface relative to the equatorial plane. Measured from the equator in degrees, i.e. from 0 ° to 90 °, and in the Northern Hemisphere is called northern latitude (has a plus sign), and in the Southern ... ... Marine Biographical Dictionary Wikipedia
geographical latitude- The angle between the plane of the equator and the normal to the surface of the earth's ellipsoid at a given point. Note Geographic latitude is measured by a meridian arc from the equator to the parallel of a given point. The account is kept from 0 to 90 ° in the north and south ... ... Technical Translator's Handbook
geographical latitude- The angular distance of any point on the Earth's surface along the meridian, counted south and north of the equator in degrees, minutes and seconds in accordance with the angle of the given latitude parallel from 0° to 90°. Syn.: latitude… Geography Dictionary
