home
Ayurveda
How to tell others your location if you don't know the address (search by coordinates). How to find the right address in an unfamiliar city

How to tell others your location if you don't know the address (search by coordinates). How to find the right address in an unfamiliar city

17.10.2019

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 .
The plane perpendicular to the earth's axis and passing through the center of the earth 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 zero 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

3.1.1. Spherical coordinates

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.

3.1.2. Astronomical coordinates

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)

3.1.3. Geodetic coordinate system

IN 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 (IN) 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 (IN)- 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)

3.2. DETERMINATION OF GEOGRAPHICAL COORDINATES OF POINTS ON THE MAP

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). Hence, 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 northwestern corner of the frame of each sheet, to the right of the longitude of the meridian, the inscription is placed: "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 points (except for the map of scale 1: 200,000) into parts of 10 "(ten seconds). On each sheet of maps of scales 1: 50,000 and 1: 100,000, in addition, they show 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 map

When compiling maps at scales of 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:

set one leg of the measuring compass to a given point, set the other leg along the shortest distance to the nearest parallel (for our map 54º40 ′);
without changing the solution of the measuring compass, install it on the side frame with minute and second divisions, one leg should be on the south parallel (for our map 54º40 ′), and the other between the 10-second points on the frame;
count the number of minutes and seconds from the south parallel to the second leg of the measuring compass;
add the result obtained to the south latitude (for our map 54º40 ′).

To determine the longitude of a given point, you must:

set one leg of the measuring compass to a given point, set the other leg along the shortest distance to the nearest meridian (for our map 18º00 ′);
without changing the solution of the measuring compass, set it to the nearest horizontal frame with minute and second divisions (for our map, the lower frame), one leg should be on the nearest meridian (for our map 18º00 ′), and the other between the 10-second points on horizontal frame;
count the number of minutes and seconds from the western (left) meridian to the second leg of the measuring compass;
add the result to the longitude of the western meridian (for our map 18º00′).

note to the fact that this method of 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 accuracy 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.

3.3. POLAR COORDINATE SYSTEM

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 ( ABOUT), 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.

3.2. BIPOLAR COORDINATE SYSTEMS

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 ABOUT 1 And ABOUT 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? To obtain 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 reference point for absolute heights is taken 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 water surface 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 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 of the 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 of the Soviet Union, Ukrainian surveyors did not invent their own national system of heights, and currently in Ukraine it is still used Baltic height system.

It should be noted that, in every necessary case, measurements are not taken 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 height or excess (h):
h = H A-H IN .
The excess of one point over another can also be positive and negative. If the absolute height of the point A greater than the absolute height of the point IN, i.e. is above the point IN, then the excess of the point A over the dot IN will be positive, and vice versa, exceeding the point IN over the dot A- negative.

Example. Absolute heights of points A And IN: H A = +124,78 m; H IN = +87,45 m. Find Mutual Exceedances of Points A And IN.

Solution. Exceeding point A over the dot IN
h A(B) = +124,78 - (+87,45) = +37,33 m.
Exceeding point IN over the dot A
h B(A) = +87,45 - (+124,78) = -37,33 m.

Example. Point absolute height A is equal to H A = +124,78 m. Exceeding point WITH over the dot A equals h C(A) = -165,06 m. Find the absolute height of a point WITH.

Solution. Point absolute height WITH is equal to
H WITH = H A + 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 A = 528.752 m - absolute mark of the point A; H" IN \u003d 28.752 m - conditional elevation of the point IN .

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

Expand the concepts: pole, equatorial plane, equator, meridian plane, meridian, parallel, degree grid, coordinates.
Relative to what planes on the globe (ellipsoid of revolution) are geographic coordinates determined?
What is the difference between astronomical geographic coordinates and geodetic coordinates?
Using the drawing, expand the concepts of "spherical latitude" and "spherical longitude".
On what surface is the position of points in the astronomical coordinate system determined?
Using the drawing, expand the concepts of "astronomical latitude" and "astronomical longitude".
On what surface is the position of points in the geodetic coordinate system determined?
Using the drawing, expand the concepts of "geodesic latitude" and "geodesic longitude".
Why, in order to improve the accuracy of determining longitude, is it necessary to connect the nearest ten-second divisions of the same name to the point with straight lines?
How can you calculate the latitude of a point if you determine the number of minutes and seconds from the northern frame of a topographic map?
What are the polar coordinates?
What is the purpose of the polar axis in a polar coordinate system?
What coordinates are called bipolar?
What is the essence of the direct geodetic problem?

Coordinates called angular and linear quantities (numbers) that determine the position of a point on a surface or in space.

In topography, such coordinate systems are used that allow the most simple and unambiguous determination of the position of points on the earth's surface, both from the results of direct measurements on the ground and using maps. These systems include geographic, flat rectangular, polar and bipolar coordinates.

Geographical coordinates(Fig.1) - angular values: latitude (j) and longitude (L), which determine the position of the object on the earth's surface relative to the origin of coordinates - the point of intersection of the initial (Greenwich) meridian with the equator. On the map, the geographic grid is indicated by a scale on all sides of the map frame. The western and eastern sides of the frame are meridians, while the northern and southern sides are parallels. In the corners of the map sheet, the geographical coordinates of the points of intersection of the sides of the frame are signed.

Rice. 1. The system of geographical coordinates on the earth's surface

In the geographic coordinate system, the position of any point on the earth's surface relative to the origin of coordinates is determined in angular measure. For the beginning, in our country and in most other states, the point of intersection of the initial (Greenwich) meridian with the equator is accepted. Being, therefore, the same for our entire planet, the system of geographical coordinates is convenient for solving problems of determining the relative position of objects located at considerable distances from each other. Therefore, in military affairs, this system is used mainly for conducting calculations related to the use of long-range combat weapons, such as ballistic missiles, aviation, etc.

Planar rectangular coordinates(Fig. 2) - linear quantities that determine the position of the object on the plane relative to the accepted origin - the intersection of two mutually perpendicular lines (coordinate axes X and Y).

In topography, each 6-degree zone has its own system of rectangular coordinates. The X-axis is the axial meridian of the zone, the Y-axis is the equator, and the point of intersection of the axial meridian with the equator is the origin of coordinates.

Rice. 2. System of flat rectangular coordinates on maps

The system of flat rectangular coordinates is zonal; it is set for each six-degree zone into which the Earth's surface is divided when it is depicted on maps in the Gaussian projection, and is intended to indicate the position of images of points on the earth's surface on a plane (map) in this projection.

The origin of coordinates in the zone is the point of intersection of the axial meridian with the equator, relative to which the position of all other points of the zone is determined in a linear measure. The origin of the zone coordinates and its coordinate axes occupy a strictly defined position on the earth's surface. Therefore, the system of flat rectangular coordinates of each zone is connected both with the coordinate systems of all other zones, and with the system of geographical coordinates.

The use of linear quantities to determine the position of points makes the system of flat rectangular coordinates very convenient for making calculations both when working on the ground and on the map. Therefore, this system finds the widest application in the troops. Rectangular coordinates indicate the position of terrain points, their battle formations and targets, with their help they determine the relative position of objects within one coordinate zone or in adjacent sections of two zones.

Polar and bipolar coordinate systems are local systems. In military practice, they are used to determine the position of some points relative to others in relatively small areas of the terrain, for example, in target designation, marking landmarks and targets, drawing up terrain maps, etc. These systems can be associated with systems of rectangular and geographical coordinates.

2. Determination of geographical coordinates and mapping of objects by known coordinates

The geographical coordinates of a point located on the map are determined from the parallels and meridians closest to it, the latitude and longitude of which are known.

The frame of the topographic map is divided into minutes, which are separated by dots into divisions of 10 seconds each. Latitudes are indicated on the sides of the frame, and longitudes are indicated on the northern and southern sides.

Rice. 3. Determination of the geographical coordinates of a point on the map (point A) and drawing a point on the map by geographical coordinates (point B)

Using the minute frame of the map, you can:

1 . Determine the geographic coordinates of any point on the map.

For example, the coordinates of point A (Fig. 3). To do this, use a measuring compass to measure the shortest distance from point A to the southern frame of the map, then attach the meter to the western frame and determine the number of minutes and seconds in the measured segment, add the resulting (measured) value of minutes and seconds (0 "27") with the latitude of the southwestern corner of the frame - 54 ° 30 ".

Latitude points on the map will be equal to: 54°30"+0"27" = 54°30"27".

Longitude defined in a similar way.

Using a measuring compass, measure the shortest distance from point A to the western frame of the map, apply the measuring compass to the southern frame, determine the number of minutes and seconds in the measured segment (2 "35"), add the obtained (measured) value to the longitude of the southwestern corner frames - 45°00".

Longitude points on the map will be equal to: 45°00"+2"35" = 45°02"35"

2. Put any point on the map according to the given geographical coordinates.

For example, point B latitude: 54°31 "08", longitude 45°01 "41".

To map a point in longitude, it is necessary to draw a true meridian through a given point, for which connect the same number of minutes along the northern and southern frames; to plot a point in latitude on a map, it is necessary to draw a parallel through this point, for which connect the same number of minutes along the western and eastern frames. The intersection of two lines will determine the location of point B.

3. Rectangular coordinate grid on topographic maps and its digitization. Additional grid at the junction of coordinate zones

The coordinate grid on the map is a grid of squares formed by lines parallel to the coordinate axes of the zone. The grid lines are drawn through an integer number of kilometers. Therefore, the coordinate grid is also called the kilometer grid, and its lines are kilometer.

On the map 1:25000, the lines forming the coordinate grid are drawn through 4 cm, that is, through 1 km on the ground, and on maps 1:50000-1:200000 through 2 cm (1.2 and 4 km on the ground, respectively). On the 1:500000 map, only the exits of the coordinate grid lines are plotted on the inner frame of each sheet after 2 cm (10 km on the ground). If necessary, coordinate lines can be drawn on the map along these exits.

On topographic maps, the values of the abscissas and ordinates of the coordinate lines (Fig. 2) are signed at the exits of the lines behind the inner frame of the sheet and nine places on each sheet of the map. The full values of abscissas and ordinates in kilometers are signed near the coordinate lines closest to the corners of the map frame and near the intersection of the coordinate lines closest to the northwestern corner. The rest of the coordinate lines are signed in abbreviated form with two digits (tens and units of kilometers). Signatures near the horizontal lines of the coordinate grid correspond to distances from the y-axis in kilometers.

Signatures near the vertical lines indicate the zone number (one or two first digits) and the distance in kilometers (always three digits) from the origin of coordinates, conditionally moved to the west of the zone's central meridian by 500 km. For example, the signature 6740 means: 6 - zone number, 740 - distance from the conditional origin in kilometers.

The outputs of the coordinate lines are given on the outer frame ( additional grid) coordinate systems of the adjacent zone.

4. Determination of rectangular coordinates of points. Drawing points on the map by their coordinates

On the coordinate grid using a compass (ruler) you can:

1. Determine the rectangular coordinates of a point on the map.

For example, points B (Fig. 2).

For this you need:

write X - digitization of the lower kilometer line of the square in which point B is located, i.e. 6657 km;
measure along the perpendicular the distance from the lower kilometer line of the square to point B and, using the linear scale of the map, determine the value of this segment in meters;
add the measured value of 575 m with the digitization value of the lower kilometer line of the square: X=6657000+575=6657575 m.

The Y ordinate is determined in the same way:

write the Y value - the digitization of the left vertical line of the square, i.e. 7363;
measure the perpendicular distance from this line to point B, i.e. 335 m;
add the measured distance to the Y digitization value of the left vertical line of the square: Y=7363000+335=7363335 m.

2. Put the target on the map according to the given coordinates.

For example, point G by coordinates: X=6658725 Y=7362360.

For this you need:

find the square in which the point G is located by the value of whole kilometers, i.e. 5862;
set aside from the lower left corner of the square a segment on the scale of the map, equal to the difference between the abscissa of the target and the lower side of the square - 725 m;
from the obtained point along the perpendicular to the right, set aside a segment equal to the difference in the ordinates of the target and the left side of the square, i.e. 360 m.

Rice. 2. Determining the rectangular coordinates of a point on the map (point B) and plotting a point on the map using rectangular coordinates (point D)

5. Accuracy of determining coordinates on maps of various scales

The accuracy of determining geographical coordinates on maps 1:25000-1:200000 is about 2 and 10 "" respectively.

The accuracy of determining the rectangular coordinates of points on a map is limited not only by its scale, but also by the magnitude of the errors allowed when shooting or compiling a map and drawing various points and terrain objects on it

Geodetic points and are plotted most accurately (with an error not exceeding 0.2 mm) on the map. objects that stand out most sharply on the ground and are visible from afar, having the value of landmarks (individual bell towers, factory chimneys, tower-type buildings). Therefore, the coordinates of such points can be determined approximately with the same accuracy with which they are plotted on the map, i.e. for a map at a scale of 1:25000 - with an accuracy of 5-7 m, for a map at a scale of 1:50000 - with an accuracy of - 10- 15 m, for a map at a scale of 1:100000 - with an accuracy of 20-30 m.

The remaining landmarks and contour points are plotted on the map, and, therefore, are determined from it with an error of up to 0.5 mm, and points related to contours that are not clearly expressed on the ground (for example, the contour of a swamp), with an error of up to 1 mm.

6. Determining the position of objects (points) in systems of polar and bipolar coordinates, mapping objects in direction and distance, in two angles or in two distances

System flat polar coordinates(Fig. 3, a) consists of a point O - the origin, or poles, and the initial direction of the OR, called polar axis.

Rice. 3. a – polar coordinates; b – bipolar coordinates

The position of the point M on the ground or on the map in this system is determined by two coordinates: the position angle θ, which is measured clockwise from the polar axis to the direction to the determined point M (from 0 to 360 °), and the distance OM = D.

Depending on the task being solved, an observation point, a firing position, a starting point for movement, etc. are taken as a pole, and a geographical (true) meridian, a magnetic meridian (the direction of a magnetic compass needle) or a direction to some landmark is taken as a polar axis .

These coordinates can be either two position angles that determine directions from points A and B to the desired point M, or distances D1=AM and D2=BM to it. The position angles, as shown in Fig. 1, b, are measured at points A and B or from the direction of the basis (i.e., angle A=BAM and angle B=ABM) or from any other directions passing through points A and B and taken as initial ones. For example, in the second case, the location of the point M is determined by the position angles θ1 and θ2, measured from the direction of the magnetic meridians. System flat bipolar (two-pole) coordinates(Fig. 3, b) consists of two poles A and B and a common axis AB, called the basis or base of the serif. The position of any point M relative to the two data on the map (terrain) points A and B is determined by the coordinates that are measured on the map or on the terrain.

Drawing the detected object on the map

This is one of the most important moments in object detection. The accuracy of determining its coordinates depends on how accurately the object (target) will be mapped.

Having found an object (target), you must first determine exactly what is detected by various signs. Then, without stopping the observation of the object and without revealing yourself, put the object on the map. There are several ways to plot an object on a map.

visually: Places a feature on the map when it is close to a known landmark.

By direction and distance: to do this, you need to orient the map, find the point of your standing on it, sight on the map the direction to the detected object and draw a line to the object from the point of your standing, then determine the distance to the object by measuring this distance on the map and commensurate it with the scale of the map.

Rice. 4. Drawing a target on the map with a straight cut from two points.

If in this way it is graphically impossible to solve the problem (the enemy interferes, poor visibility, etc.), then you need to accurately measure the azimuth to the object, then translate it into a directional angle and draw a direction on the map from the standing point, on which to plot the distance to the object.

To get the directional angle, you need to add the magnetic declination of this map (direction correction) to the magnetic azimuth.

straight serif. In this way, an object is put on a map of 2-3 points from which it is possible to observe it. To do this, from each selected point, the direction to the object is drawn on the oriented map, then the intersection of straight lines determines the location of the object.

7. Ways of targeting on the map: in graphic coordinates, flat rectangular coordinates (full and abbreviated), by squares of a kilometer grid (up to a whole square, up to 1/4, up to 1/9 of a square), from a landmark, from a conditional line, by azimuth and target range, in the bipolar coordinate system

The ability to quickly and correctly indicate targets, landmarks and other objects on the ground is important for controlling subunits and fire in combat or for organizing combat.

Target designation in geographic coordinates It is used very rarely and only in those cases when the targets are removed from a given point on the map at a considerable distance, expressed in tens or hundreds of kilometers. In this case, geographical coordinates are determined from the map, as described in question No. 2 of this lesson.

The location of the target (object) is indicated by latitude and longitude, for example, height 245.2 (40 ° 8 "40" N, 65 ° 31 "00" E). On the eastern (western), northern (southern) sides of the topographic frame, mark the position of the target in latitude and longitude with a prick of a compass. From these marks, perpendiculars are lowered into the depth of the sheet of the topographic map until they intersect (commander's rulers, standard sheets of paper are applied). The point of intersection of the perpendiculars is the position of the target on the map.

For approximate target designation rectangular coordinates it is enough to indicate on the map the square of the grid in which the object is located. The square is always indicated by the numbers of kilometer lines, the intersection of which forms the southwestern (lower left) corner. When indicating the square, the cards follow the rule: first they name two numbers signed at the horizontal line (at the western side), that is, the “X” coordinate, and then two numbers at the vertical line (south side of the sheet), that is, the “Y” coordinate. In this case, "X" and "Y" are not spoken. For example, enemy tanks are spotted. When transmitting a report by radiotelephone, the square number is pronounced: eighty-eight zero two.

If the position of a point (object) needs to be determined more accurately, then full or abbreviated coordinates are used.

Work with full coordinates. For example, it is required to determine the coordinates of a road sign in square 8803 on a map at a scale of 1:50000. First, determine what is the distance from the lower horizontal side of the square to the road sign (for example, 600 m on the ground). In the same way, measure the distance from the left vertical side of the square (for example, 500 m). Now, by digitizing kilometer lines, we determine the full coordinates of the object. The horizontal line has the signature 5988 (X), adding the distance from this line to the road sign, we get: X=5988600. In the same way, we determine the vertical line and get 2403500. The full coordinates of the road sign are as follows: X=5988600 m, Y=2403500 m.

Abbreviated coordinates respectively will be equal: X=88600 m, Y=03500 m.

If it is required to clarify the position of the target in a square, then target designation is used by letter or number inside the square of the kilometer grid.

When targeting in a literal way inside the square of the kilometer grid, the square is conditionally divided into 4 parts, each part is assigned a capital letter of the Russian alphabet.

The second way - digital way target designation inside the kilometer grid square (target designation by snail ). This method got its name from the arrangement of conditional digital squares inside the square of the kilometer grid. They are arranged as if in a spiral, while the square is divided into 9 parts.

When targeting in these cases, they name the square in which the target is located, and add a letter or number that specifies the position of the target inside the square. For example, a height of 51.8 (5863-A) or a high-voltage support (5762-2) (see Fig. 2).

Target designation from a landmark is the simplest and most common method of target designation. With this method of target designation, the nearest landmark to the target is first called, then the angle between the direction to the landmark and the direction to the target in goniometer divisions (measured with binoculars) and the distance to the target in meters. For example: "Landmark two, forty to the right, further two hundred, at a separate bush - a machine gun."

target designation from the conditional line usually used in combat vehicles. With this method, two points are selected on the map in the direction of action and connected by a straight line, relative to which target designation will be carried out. This line is indicated by letters, divided into centimeter divisions and numbered starting from zero. Such a construction is done on the maps of both the transmitting and receiving target designation.

Target designation from a conditional line is usually used in combat vehicles. With this method, two points are selected on the map in the direction of action and connected by a straight line (Fig. 5), relative to which target designation will be carried out. This line is indicated by letters, divided into centimeter divisions and numbered starting from zero.

Rice. 5. Target designation from a conditional line

Such a construction is done on the maps of both the transmitting and receiving target designation.

The position of the target relative to the conditional line is determined by two coordinates: a segment from the starting point to the base of the perpendicular, lowered from the target location point to the conditional line, and a segment of the perpendicular from the conditional line to the target.

When targeting, the conditional name of the line is called, then the number of centimeters and millimeters contained in the first segment, and, finally, the direction (left or right) and the length of the second segment. For example: “Direct AC, five, seven; zero to the right, six - NP.

Target designation from a conditional line can be issued by indicating the direction to the target at an angle from the conditional line and the distance to the target, for example: "Direct AC, right 3-40, one thousand two hundred - machine gun."

target designation in azimuth and range to the target. The azimuth of the direction to the target is determined using a compass in degrees, and the distance to it is determined using an observation device or by eye in meters. For example: "Azimuth thirty-five, range six hundred - a tank in a trench." This method is most often used in areas where there are few landmarks.

8. Problem solving

Determining the coordinates of terrain points (objects) and target designation on the map is practiced practically on training maps using pre-prepared points (marked objects).

Each student determines geographic and rectangular coordinates (maps objects at known coordinates).

Methods of target designation on the map are worked out: in flat rectangular coordinates (full and abbreviated), in squares of a kilometer grid (up to a whole square, up to 1/4, up to 1/9 of a square), from a landmark, in azimuth and range of the target.

Determination of coordinates independently.

Determining latitude and longitude on a map or on a globe is one of the most accurate ways to determine the location of a large object. Determination of geographical coordinates, both historically and at the moment, is relevant in navigation, for orientation in the area, when moving on foot or in transport.

Each object, which is distinguished by a stable location, can have not only its own postal address, but also a geographical address, reflected precisely in latitude and longitude. When asked how to determine the latitude and longitude on the map, the video and text instructions are quite detailed, it is not difficult to answer this question, and in order to use knowledge in practice, you just need to pay due attention to the instructions that people have been using for hundreds of years.

horizontal lines

Latitude is expressed in degrees indicated on the map, and represents the distance to a particular point, relative to the Equator, it can be either positive or negative, respectively - North and South. Southern latitudes - from the Equator to the South Pole (negative), Northern - from the Equator to the North Pole (positive).

The Equator is taken as the latitude of the zero value, its value increases from the Equator to the poles and can have a value from 0 ° to 90 °, both in one direction and in the other.

North latitude is indicated by the English letter N (from North), South - S (from South).

vertical lines

Longitude is expressed in degrees and shows the distance from any point to the position of Greenwich (zero meridian), it can have a positive and negative value, and is also divided into hemispheres. To the west of Greenwich - positive, Western. To the east - negative or Eastern.

The entire circumference of the Earth is defined as 360°, with 180° making up the Western and Eastern hemispheres. Longitude is higher the farther it is from Greenwich (zero meridian) and can range from 0 to 180°.

The designation of the western longitude comes from the English word West, by the first letter - W. And the eastern one is indicated by the word East and the letter E.

Determination of coordinates - simply and quickly

The step between degrees is 111.11 kilometers, minutes and seconds are fractional degrees, allowing you to determine the position of the object with an accuracy of several meters (5-20 approximately).

To find out the latitude of a point, it is necessary to establish whether it belongs to the northern or southern hemisphere (above or below the Equator). Parallels in tens of degrees are signed on the right or left side of the map (or both). It is necessary to establish between which parallels the desired position is located. Next, you need to use measuring instruments or marks on the map to set the distance from the selected point to the nearest parallel from the Equator in degrees;
To determine the longitude of a point, you must first find out its position on the map relative to Greenwich - the western hemisphere is located to the right of the zero meridian, and the eastern hemisphere is located to the left. Longitude can be labeled on the top and bottom of the map, as well as at the point of intersection with the Equator. It is necessary to set the distance of the desired position to the nearest meridian from Greenwich;
The intersection point between meridians and parallels is the geographic coordinates of the selected point.

It is worth considering that you can set the exact location of the point if you have a sufficiently detailed map, where it is possible to use not only degrees, but also minutes and seconds. A degree is 111 kilometers, and its minute is already 1.85 kilometers, a second allows you to specify the position of a point up to 30 meters.

How to determine the latitude and longitude on the Yandex map and Google map

In order to find out the characteristics of the area in the Google mapping system, you need to move the mouse over the area of interest, while you can adjust the scale using the mouse wheel and move the map by pressing the left mouse button and moving the device in the desired direction. After clicking on the desired position with the right mouse button, you need to select the “what is here” item in the drop-down menu, the system will immediately enter the result in the search line above and display information about the objects located in the specified area and other characteristics of the area.

Instruction

First you must determine the geographic longitude. This value is the deviation of the object from the prime meridian, from 0° to 180°. If the desired point is east of Greenwich, the value is called the east longitude, if it is west, the longitude. One degree is equal to 1/360 of a part.

Pay attention to the fact that in one hour the Earth turns 15° of longitude, and in four minutes it moves 1°. Your watch must show the correct time. To find out geographic longitude, you need to set the noon time.

Find a straight stick 1-1.5 meters long. Stick it vertically into the ground. As soon as the shadow from the stick falls from south to north, and the sundial “shows” 12 hours, note the time. This is the local noon. Convert your data to Greenwich Mean Time.

Subtract 12 from the result obtained. Convert this difference to a degree measure. This method does not give a 100% result, and the longitude from your calculations may differ from the true longitude of your location by 0°-4°.

Remember, if local noon came before noon GMT - this is longitude, if later -. Now you must set the geographic latitude. This value shows the deviation of the object from the equator to the north (northern latitude) or to the south (latitude) side, from 0° to 90°.

Please note that the length of one geographic degree is approximately equal to 111.12 km. To determine the geographical latitude, you need to wait for the night. Prepare the protractor and point its lower part (base) at the polar star.

Position the protractor upside down, but so that the zero degree is opposite the polar star. See which degree is opposite the hole in the middle of the protractor. This will be the geographic latitude.

Sources:

Determination of latitude and longitude
how to determine the coordinates of the area

With the development of interregional labor relations, as well as in personal interests, there is a need to move from city to city, other settlements, or to places where they have never been before. There are now many ways to determine coordinates desired destination.

Instruction

Start installing the downloaded file by clicking the "install" button and wait for the program to load.

Select a start location and check the box.

Also define coordinates You can use Bing.com.
Enter the area you are interested in in the fields opposite the logo and click search.

Select Directions from here with the right mouse button, a window will appear on the left side. In it, indicate the destination area. Red flag is the starting location, green flag is the destination location. In the same place on the left side, choose how you would like to get there.

Find the elevation angle using the set screw and Vernier scale.

Globes and maps have their own coordinate system. Thanks to this, any object of our planet can be applied and found on them. Geographic coordinates are longitude and latitude, these angular values are measured in degrees. With their help, you can determine the position of an object on the surface of our planet relative to the prime meridian and the equator.

Instruction

After determining the local noon, note the clock. Then make a correction to the resulting difference. The fact is that the angular velocity of movement is not constant and depends on the time of year. So add (or subtract) the correction to the result.

Consider an example. Let's say today is May 2nd. The clock is set in Moscow. In summer, Moscow summer time differs from world time by 4 hours. At local noon, set by the sundial, the clock showed 18:36. Thus, the world time at the moment is 14:35. Subtract 12 hours from this time and get 02:36. The correction for May 2 is 3 minutes (this time should be added). Translating the result obtained into an angular measure, we obtain 39 degrees west longitude. The described method allows you to determine with an accuracy of up to three degrees. Given that in an emergency you will not have a table of the equation of time at hand to correct the calculations, the result may differ from the true one.

To determine the geographic latitude, you will need a protractor and a plumb line. Make a homemade protractor from two rectangular strips, fastening them in the form of a compass.

In the center of the protractor, fasten the thread with the load (it will play the role of a plumb line). Aim the base of the protractor at the pole star.

Subtract 90 degrees from the angle between the base of the protractor and the plumb line. We got the angle between the polar star and the horizon. Since it has a deviation from the axis of the pole by only one degree, the angle between the direction to the star and the horizon will be the desired latitude of the area in which you are located.

Sources:

Determination of latitude and longitude

Knowing the latitude at which your home is located can be very helpful. Despite the fact that today the exact location can be easily determined using compact navigators, navigating the terrain in the "old" ways is still relevant and very interesting.

You will need

Minimum knowledge of the starry sky, as well as:
- two slats
- bolt with nut
- protractor.

Instruction

To determine geographic latitude places, you need to make a simple protractor.
Take two rectangular wooden planks one and a half to two meters long and fasten their ends hingedly according to the principle of a compass. Stick one leg of the compass into the ground and set it vertically on a plumb line. The second should move tight enough on the hinge. As a hinge, you can use a bolt with.
These preliminary works must be done during the day, before dusk. The weather, of course, must be chosen cloudless enough to be able to observe the starry sky.

With the onset of dusk, go out into the courtyard and find the North Star in the sky.
To determine the location, find the Big Dipper. To do this, turn your face to the north and try to make out the seven that form the outline of a large bucket. Usually this constellation is easily found.
Now mentally draw a line between the two extreme stars of the bucket towards the bell and measure five segments on it equal to the distance between these stars.
You will fall on a fairly bright star, which will be the North. Make sure that you are not mistaken: the star found must be the end of the small bucket - the constellation Ursa Minor.

Direct the movable leg of the compass strictly to the North Star. To do this, you will have to turn a little into the device and again set the vertical rail along the plumb line. Now, as it were, "aim" at the star - so the surveyors - and fix the position of the device by screwing the nut on the hinge.
Now, using a protractor, measure the angle between the direction of the star and the vertical stand. This can be done already in the light by moving the device into the room.
From the result, subtract 90 - this will be the latitude of your place.

Distribution area of cyclamens in the wild

Cyclamen is a heat-loving plant that prefers moderate moisture and shade. Therefore, most species grow in thickets of forests or shrub plantations, as well as in rock crevices. On the territory of the former Soviet Union, cyclamens are found in Ukraine, in the Crimea, in the south-west of the Caucasus, in the south of Azerbaijan, in the Krasnodar Territory. From the countries of Central Europe, France, Germany, Poland, Bulgaria can boast of the habitation of cyclamens, where plants are mainly found in the south and southeast.

Species from these regions, or “natives” from northern Turkey, are quite suitable for breeding in a garden of the European part of Russia, especially since the eastern Mediterranean is a real cyclamen: Turkey, Iran, Syria, Cyprus, Greece, Israel. In the west of the Mediterranean, in Italy and Spain, cyclamens also grow. On a hill near the Italian lake Kastel Kaldorf, one can observe their friendly flowering, which rarely happens in nature. After all, most wild species are on the verge of extinction. Northern Tunisia and Algeria are rich in cyclamens.

Varieties of wild cyclamens

I must say that depending on the habitat, cyclamens have different endurance. For example, ivy-leaved cyclamen or Neapolitan, common in the middle part of Europe, may well overwinter in the conditions of a snowy Russian winter with a temperature of -20 ° C. Produced from the general range of heat-loving species of cyclamen European (purple). It is characterized by a silver leaf pattern and flowering not in autumn, like most cyclamen, but starting in June.

Sometimes it is extremely unfair to treat cyclamens growing in the territories of Abkhazia, Azerbaijan, Adjara, calling all species “Caucasian”. After all, here they distinguish such varieties as Circassian, Abkhazian, Colchian (Pontic), spring, graceful, Kos. The latter is well known in Iran, Turkey, Syria, Israel and Bulgaria. Prefers to grow among coniferous vegetation. Its flowers are larger the farther to the east. The largest are the flowers of Kos cyclamen on the shores of the Caspian Sea, in Azerbaijan.

In the south of France and the mountainous regions of Spain, a small species of cyclamen is common - Balearic, belonging to spring flowering. African cyclamen is considered the most heat-loving, the hallmarks of which are bright green large leaves that appear on the surface after flowers. The habitat of many species of cyclamen can be guessed by the name: African cyclamen, Cypriot, Grecum, Persian. Persian, like African, does not tolerate even mild frosts at all.

The Russian name for mountain ash comes from the word "ripple". Most likely, this is due to the fact that its clusters are bright and visible even from a distance. But this name refers only to trees with red and yellow fruits. The widespread black rowan has a completely different scientific name - chokeberry, although it also belongs to the Rose family.

Mountain ash is a unique tree with a branched root system, which allows it to grow in various latitudes, even in permafrost, and withstand frosts down to -50 degrees Celsius. As a rule, the height of the mountain ash is about 4–5 m, but in mild climates there are specimens reaching 15 m in height. In cold and harsh terrain, it does not grow above 50 cm.

Rowan refers to fruit trees, but its fruits are not berries at all, as is commonly believed, but the so-called false drupes. They have an oval-rounded shape and a core with stones, therefore, in their structure they are similar to an apple, only much smaller. Rowan begins to bear fruit, reaching the age of 7 - 8 years, and often turns out to be a long-liver - some trees live up to 200 years. Mountain ash, growing for more than 20 years, can yield over 100 kg per year.

Places of distribution

Various varieties and hybrids of mountain ash are widely distributed throughout Europe, Asia, and North America. The most common species in our latitudes is the mountain ash (Sorbus aucuparia), which grows in abundance in gardens and forests almost throughout Russia and does not require any special care. Its most popular forms are Nevezhinsky mountain ash and yellow-fruited mountain ash. In the southern, southwestern, less often in the middle regions of Russia, the Crimean large-fruited mountain ash (Sorbus domestica), which is also called domestic, is bred. The peculiarity of this species is large pear-shaped fruits, reaching 3.5 cm in diameter and 20 g in weight, which have a particularly pleasant taste due to the high sugar content (about 14%).

Mountain ash grows everywhere throughout the forest and forest-steppe zone of the European part of Russia (with the exception, perhaps, of the Far North), in the wooded regions of the Crimea and the Caucasus. It can often be found in coniferous and mixed coniferous-broad-leaved forests, along the banks of lakes and rivers, in fields and along roads. She does not like shady places and mainly grows not in the dense forest thicket, but on the edges and clearings of forests. Mountain ash is often an adornment of city parks, alleys and squares.

Latitude

Latitude- angle φ between the local direction of the zenith and the plane of the equator, counted from 0° to 90° on both sides of 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. It is customary to speak of latitudes close to the poles as high, and about those close to the equator - as about low.

Due to the difference in the shape of the Earth from the ball, the geographic latitude of the points is somewhat different from their geocentric latitude, that is, from the angle between the direction to a given point from the center of the Earth and the plane of the equator.

The latitude of a place can be determined using astronomical instruments such as a sextant or gnomon (direct measurement), you can also use GPS or GLONASS systems (indirect measurement).

Longitude

Longitude- dihedral angle λ between the plane of the meridian passing through the given point, and the plane of the initial zero meridian, from which the longitude is counted. Longitude from 0° to 180° east of the prime meridian is called east, to the west - west. Eastern longitudes are considered to be positive, western - negative.

Height

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.

Distance from the earth's surface (up or down) is often used to describe a location, but "not" serves as a coordinate.

Geographic coordinate system

ω E = − V N / R (\displaystyle \omega _(E)=-V_(N)/R) ω N = V E / R + U cos ⁡ (φ) (\displaystyle \omega _(N)=V_(E)/R+U\cos(\varphi)) ω U p = V E R t g (φ) + U sin ⁡ (φ) (\displaystyle \omega _(Up)=(\frac (V_(E))(R))tg(\varphi)+U\sin(\ varphi)) where R is the radius of the earth, U is the angular velocity of the earth's rotation, V N (\displaystyle V_(N)) is the speed of the vehicle to the north, V E (\displaystyle V_(E))- to the East, φ (\displaystyle \varphi )- latitude, λ (\displaystyle \lambda )- longitude.

The main shortcoming in the practical application of the G.S.K. in navigation is the large values of the angular velocity of this system at high latitudes, which increase up to infinity at the pole. Therefore, instead of G. S. K., a semi-free SK in azimuth is used.

Semi-free in azimuth coordinate system

The semi-free in azimuth S.K. differs from the G.S.K. only by one equation, which has the form:

ω U p = U sin ⁡ (φ) (\displaystyle \omega _(Up)=U\sin(\varphi))

Accordingly, the system has the same initial position, carried out according to the formula

N = Y w cos ⁡ (ε) + X w sin ⁡ (ε) (\displaystyle N=Y_(w)\cos(\varepsilon)+X_(w)\sin(\varepsilon)) E = − Y w sin ⁡ (ε) + X w cos ⁡ (ε) (\displaystyle E=-Y_(w)\sin(\varepsilon)+X_(w)\cos(\varepsilon))

In reality, all calculations are carried out in this system, and then, to issue output information, the coordinates are transformed into the GCS.

Recording formats for geographic coordinates

Any ellipsoid (or geoid) can be used to record geographic coordinates, but WGS 84 and Krasovsky (on the territory of the Russian Federation) are most often used.

Coordinates (latitude −90° to +90°, longitude −180° to +180°) can be written: