Geographic coordinates and definition of them on the map

Geographical coordinates- angular values \u200b\u200b(latitude and longitude), determining the position of objects on the earth's surface and on the map. They are divided into astronomical, obtained from astronomical observations, and geodesic, obtained from geodesic measurements on the earth's surface.

Astronomical coordinatesdetermine the position of the earth's surfaces on the surface of the geoid, where they are designed by the sheer lines; Geodesic coordinates determine the position of points on the surface of the earth's ellipsoid, where they are designed by the normals to this surface.

The discrepancies between astronomical and geodesic coordinates are due to the evasion of the sheer line from the normal to the surface of the earth's ellipsoid. For most of the territory globe They do not exceed 3-4 "" or in a linear measure 100 m. The maximum dodging of the sheer line reaches 40 "".

On the topographic maps Applied geodesic coordinates. In practice, when working with cards, they are usually called geographical.

The geographical coordinates of any point M is its latitude of B and Longitude L.

Latitude Points - The angle composed of the plane of the equator and the normal to the surface of the earth's ellipsoid passing through this point. The account of the latitude is carried out on the arc meridian from the equator to the poles from 0 to 90 o; In the northern hemisphere, the latitude is called northern (positive), in southern - southern (negative).

Longitude point - Dwarbon angle between the plane of the initial (Greenwich) meridian and the meridian plane of this point. The longitude account is conducted on an equator arc or parallels in both directions from the initial meridian, from 0 to 180. The longitude of the points located to the east of Greenwich up to 180 ° is called Eastern (positive), to the west - Western (negative).

Geographic (cartographic, degree) Grid - image on map of lines of parallels and meridians; Used to determine geographic (geodesic) coordinates of points (objects) and target designation. On topographic maps of the line of parallels and meridians are the internal framework of sheets; Their latitude and longitude subscribe to the corners of each sheet.

The geographical mesh is fully shown only on topographic maps of scale 1: 500,000 (parallels were carried out after 30 ", and meridians - after 20") and 1: 1 000 000 (parallels were carried out after 1O, and the meridians are 40 "). Inside each sheet Maps on the lines of parallels and meridians are signed by their latitude and longitude that allow you to determine geographical coordinates On the big gluing card.

On the maps of scale 1: 25 000, 1: 50,000, 1: 100 000 and 1: 200,000, the sides of the framework are divided into segments equal to degree 1 ". Minute segments are shaded after one and separated by points (except for the map of scale 1: 200,000) part 10 "". In addition, inside each sheet of scale cards 1:50 000 and 1: 100 000, the intersection of medium parallels and meridian is shown and is given from digitization in degrees and minutes, and the outputs of minute divisions are given along the internal frame. Strokes with a length of 2-3mm, for which you can draw parallels and meridians on the map glued from several sheets.

If the territory on which the map is created is in the Western Hemisphere, then in the north-western corner of the sheet of the sheet the right to sign the longitude of the Meridian, the inscription "To the West of Greenwich" is placed.

Determination of geographic coordinates of the point on the map is made according to the nearest parallels and meridian, the latitude and longitude of which are known. To do this, on the maps of scale 1: 25,000 - 1: 200,000, it is necessary to pre-conduct the south of the parallel and west of 0 meridian, connecting the corresponding strokes on the sides of the sheet frame (Fig. 2). Then, from the lines taken segments to the determined point (AA1, AA2), we apply them to degree scales on the frames of the frame and produce reports. In the example in fig. 2 point A has coordinates B \u003d 54O35 "40" "northern latitude, L \u003d 37O41" 30 "" Eastern longitude.

Applying a point on the map on geographic coordinates. On the western and eastern sides of the card sheet frame, the countdowns corresponding to the latitude of the point are noted. The stitution counting starts from the digitization of the south side of the frame and continue per minute and second gaps. Then through these thies are carried out a line - parallel points.

In the same way, the meridian point is built through the point, only the longitude is counted in southern and northern sides of the frame. The intersection of parallels and meridian will indicate the position of this point on the map.

In fig. 2 This is an example of applying to a map of the point M by coordinates B \u003d 54O38.4 "S.Sh., L \u003d 37O34.4" V.D.

Geographic coordinates consist of two components: latitude and longitude, angle valuesUsing which each person can determine the location of any object on the world map. The study of the latitude and longitude of the globe was engaged in ancient times.

The concept of geographic latitude

The latitude is a geographical coordinate among the systems of spherical coordinates, which determines the points located on the surface of the Earth relative to the equator. The geographical latitude of objects that are located in the northern hemisphere are considered positive in the southern hemisphere - negative.

In geography, there is the concept of southern and northern latitudes. Determine which latitude is southern, and what northern simply: if the point moves from the equator to the side North Pole.She falls into the zone of northern latitudes.

The latitude on the map is depicted with lines walking in parallel to the equator and each other, hence the name of these lines - parallels. The distance between the parallel is measured not in kilometers, but in degrees, in minutes and seconds.

Each degree consists of 60 minutes, 1 minute - out of 60 seconds. The equator is zero breadth, the Northern and South Pole is located 90 degrees of Northern and 90 degrees of southern latitude, respectively.

One degree geographical longitude is 1/360 of the length of the equator.

The concept of geographic longitude

Longitude is the coordinate in the geographic coordinate system, which determines the location of the point relative to the zero meridian. Thanks to the longitude, we can find out the position of the subject regarding the West and the East.

In the geographical science of the zero point of the geographical longitude, it is customary to consider the Greenwich Laboratory, which is located in the east of London (Greenwich Meridian).

Lines that define longitude are called meridians. All meridians run perpendicular to the equator lines. All meridians intersect at two points - in the North and South Pole.

The territories that are located in the east of Greenwich Meridian are called the area of \u200b\u200boriental longitudes, the territory in the western direction is the region of Western longitude.

olshita continents is located in the field of oriental longitude, only two continents are the exception - South and North America. Points that are located on meridians have the same longitude, but different latitudes.

1/180 part of the meridian is one degree of latitude. The average length of one degree latitude becomes approximately 111 km. Eastern longitude indicators are considered positive, indicators of Western longitude - negative.

Determine the location of the point on the planet Earth, as on any other planet of the spherical form, possibly with the help of geographic coordinates - latitude and longitude. The intersections at the right angle of circles and arcs create an appropriate grid, which allows you to unambiguously determine the coordinates. Visual example - Ordinary school globe, distinguished by horizontal circles and vertical arcs. About how to use the globe will be talked below.

This system is measured in degrees (degrees of the angle). The angle is calculated strictly from the center of the sphere to the point on the surface. Regarding the axis, the degree of an angle of latitude is calculated vertically, longitude - horizontally. To calculate the exact coordinates, there are special formulas, where another value is not rarely found - the height that serves mainly to represent the three-dimensional space and allows calculations to determine the position of the point relative to the sea level.

Latitude and longitude - Terms and definitions

The earth's sphere is separated by an imaginary horizontal line into two equal parts of the world - the Northern and South Hemisphere - on a positive and negative pole, respectively. So the definitions of northern and southern latitudes are introduced. The latitude is presented in the form of parallel relative to the equator of circles, called parallels. The equator itself with the value of 0 degrees is the starting point for measurements. The closer the parallel to the upper or lower pole, the smaller its diameter and the higher or below the angular degree. For example, the city of Moscow is located at the 55th degree of northern latitude, which determines the location of the capital as approximately equidistant and from the equator, and from the North Pole.

Meridian is the so-called longitude, represented in the form of a vertical arc strictly perpendicular to the circles of parallel. The sphere is divided into 360 meridians. The point of reference is zero meridian (0 degrees), the arcs of which are vertically through the points of the North and south Poles. and distributed in the eastern and western directions. This defines the angle of longitude from 0 to 180 degrees, calculated by the values \u200b\u200bfrom the center to the extreme points to the east or south.

Unlike the latitude, the point of reference is the equatorial line, any meridian can be zero. But for convenience, namely, the convenience of time reference, identified Greenwich Meridian.

Geographic coordinates - place and time

Latitude and longitude allow you to assign one or another place on the planet exact geographical address measured by degrees. Degrees, in turn, are divided into smaller values, such as minutes and seconds. Each degree is crushed at 60 parts (minutes), and a minute for 60 seconds. On the example of Moscow, the entry looks like this: 55 ° 45 '7 "N, 37 ° 36' 56" E or 55 degrees, 45 minutes, 7 seconds of northern latitude and 37 degrees, 36 minutes, 56 seconds of southern longitude.

The interval between the meridians is 15 degrees and about 111 km along the equator line - such a distance of the earth, turning, passes in one hour. For the total turn of the quarter, it will take 24 hours.

Using globe

The land model is accurately transferred to the globe with a realistic drawing of all the mainland, seas and oceans. As auxiliary lines were held on the map of the globe Parallel and Meridians. Almost any globe has a gray-shaped meridian in its design, which is installed on the basis and serves as auxiliary measure.

The meridian arc is equipped with a special degree scale, which determines the latitude. Longitude can be found by another scale - hoop, horizontally installed at the equator level. I marked your finger the desired place and rotating the globe around its axis to the auxiliary arc, fix the value of the latitude (depending on the location of the object it will be either northern or southern). Then note the data of the equator scales at the site of its intersection with the meridian arc and determine the longitude. Learn - Eastern or South Longitude, you can only relatively zero meridian.

The position of each point on the earth's surface determine its coordinates: latter and longitude (Fig. 3).

Lamb called an angle formed by a sheer line passing through setpoint On the surface of the Earth, and the plane of the equator (in Fig. 3 for the point M Cor Angle).

In whatever point on the globe, there was no observer, its strength will always be directed towards the center of the Earth. This direction is called sheer, or vertical.

The latitude is measured by the arc of the meridian from the equator to the parallel of this point ranging from 0 to 90 ° and is indicated by the letter F. Thus, the geographic parallel EABQ is a geometric location of points having the same latitude.

Depending on which hemisphere is the point, the name of Northern (N) or South (S) is applied latitude.

Longitude The dwarf corner is called between the planes of the initial meridian and the meridian of this point (in fig. 3 for the point M angle of AOS). The longitude is measured by less than the equator arc between the initial meridian and the meridian of this point ranging from 0 to 180 ° and is indicated by the letter l. Thus, the geographical meridian PN MCPS is a geometric location of points having the same longitude.

Depending on which hemisphere is located, the longitude is called Eastern (O ST) or Western (W).

The difference of latitudes and the difference of longitude

During swimming, the ship continuously changes its place on the surface of the Earth, therefore, its coordinates are changed. The magnitude of the AF latitude changes, obtained when moving the vessel from the MI waste point to the arrival point C1, is called the difference is short (RS). The RSH is measured by an arc of a meridian between parallels of waste and arrival points M1C1 (Fig. 4).

Fig. four

The name of the RSH depends on the location of the parallel points of the parish relative to the parallel of the waste point. If the parallel of the arrival point is located north of the parallel of the waste point, the RSH is considered to be made to N, and if south - then to S.

The magnitude of the change in the longitude of AL, which is obtained when the ship is moving from the M1 deduction point to the C2 arrival point, is called the difference of longitude (RD). The RD is measured by a smaller arc of the equator between the meridians of the waste point and the MSN arrival point (see Fig. 4). If, in the transition of the ship, the Eastern longitude increases or Western decreases, then the RD is considered to be made to O ST, and if the Eastern longitude decreases or Western increases, then to W. To determine the RS and PD, use the formulas:

RS \u003d φ1 - φ2; (one)

RD \u003d λ1 - λ2 (2)

Where φ1 is the latitude of the waste point;

φ2 - the latitude of the parish point;

λ1 - the longitude of the departure point;

λ2 - longitude of the parish point.

At the same time, the northern latitudes and oriental longitudes are considered positive and the sign plus is attributed to them, and the southern latitudes and western longitudes are negative and they are attributed to the minus sign. When solving problems according to formulas (1) and (2), in the case of positive results, it will be made to N, and the RD - to O ST (see Example 1), and in the case negative results RSH it will be to S, and RD - to W (see example 2). Upon receipt of the result of the RD, more than 180 ° with a negative sign must be added 360 ° (see example 3), and if the result of the RD is greater than 180 ° with a positive sign, it is necessary to subtract 360 ° (see Example 4).

Example 1. Known: φ1 \u003d 62 ° 49 "n; λ1 \u003d 34 ° 49" o ST; φ2 \u003d 72 ° 50 "n; λ2 \u003d 80 ° 56" o ST.

Find RSH and RD.

Decision.

Example 2. Known: φ1 \u003d 72 ° 50 "n; λ1 \u003d: 80 ° 56" o ST: φ2 \u003d 62 o ST 49 "N;

Find RSH and RD.

On Yandex maps, geographic coordinates are recognized in degrees presented as decimal fractions. At the same time, several other coordinate recording formats are used, for example, in degrees, minutes and seconds.

Coordinates are a pair of numbers that defines the location of the object on the map.

The first figure in the format adopted on Yandex maps is, or the angle between the local direction of the zenith (that is, the direction indicating directly upwards above the specific place) and the plane of the equator. The northern latitude is denoted by the letter N, South - Letter S.

The second digit is the longitude, or the angle between the meridian plane (the line of section of the surface of the globe with a plane passing through this point and the axis of rotation of the Earth) and the plane of the initial zero (Greenwich) meridian. Long distance from 0 ° to 180 ° to the east of the zero meridian is called Eastern (E), to the West - Western (W).

Enter coordinates on Yandex maps

Open the browser and in the address bar, dial maps.yandex.ru, or open the Yandex card application to or. In the search string, enter the coordinates, for example: 55.751710,37.617019 - then click "Find". In the application to call a search string, you must first click on the magnifying glass icon (usually it is located at the bottom of the screen). Note that the input format of the coordinate must be like this: first the latitude, then longitude; whole part coordinates separated from the fractional part of the point; Figures do not contain spaces; The latitude and longitude are separated by the comma.

After clicking on the "Find" button, the marker will move to the point that the coordinates describe are - you can now build a route.

To the left of the map will be displayed an address corresponding to the coordinates, as well as alternative representation - with degrees, minutes and seconds. In our case, it will look like this:
Latitude: 55 ° 45'6.16 "n (55.75171)
Longitude: 37 ° 37'1.27 "E (37.617019)

If you enter the coordinates not in that sequence - for example, at first the longitude, and then latitude (some navigators and other electronic mapping services work with data in such a sequence) - on Yandex maps you can quickly change the order of numbers. To do this, click on the "Swap Lay" link under the complete description of the coordinates, and the marker will move to the correct point.