What is the geographic latitude of a point. What is latitude and longitude in geography? Bipolar coordinate systems

22.05.2021

Geographic latitude and longitude are plotted on a world map. With their help, it is easy to determine the location of the object.

A geographical map of the world is a reduced projection of the earth's surface on a plane. Continents, islands, oceans, seas, rivers, as well as countries, large cities and other objects are applied on it.

A coordinate grid is plotted on a geographic map.
On it you can see clearly information about the continents, seas and oceans, and the map allows you to create an image of the relief of the world.
Using a geographical map, you can calculate the distance between cities and countries. It is also convenient to search for the location of land and ocean objects.

The shape of the Earth is like a sphere. If you need to determine a point on the surface of this sphere, then you can use the globe, which is our planet in miniature. But there is the most common way to find a point on Earth - these are geographical coordinates - latitude and longitude. These parallels are measured in degrees.

Geographic map of the world with latitude and longitude - photo:

The parallels that are drawn along and across the entire map are latitude and longitude. With their help, you can quickly and easily find any place in the world.

The geographical map of the hemispheres is convenient for perception. Africa, Eurasia and Australia are depicted on one hemisphere (eastern). On the other - the western hemisphere - North and South America.

Even our ancestors were engaged in the study of latitude and longitude. Even then there were maps of the world, not similar to modern ones, but with their help you can also determine where and what object is located. A simple explanation of what the geographic latitude and longitude of an object on a map is:

Latitude is a coordinate value in the system of spherical numbers that defines a point on the surface of our planet relative to the equator.

If the objects are located in the northern hemisphere, then the geographic latitude is called positive, if in the southern hemisphere - negative.
South latitude - the object is moving from the equator towards the North Pole.
North latitude - the object is moving towards the South Pole from the equator.
On a map, latitudes are lines that are parallel to each other. The distance between these lines is measured in degrees, minutes, seconds. One degree is 60 minutes and one minute is 60 seconds.
The equator is zero latitude.

Longitude is a coordinate value that determines the location of the object relative to the zero meridian.

This coordinate allows you to find out the location of the object relative to the west and east.
Lines of longitude are meridians. They are located perpendicular to the equator.
The zero point of longitude in geography is the Greenwich Laboratory, which is located in east London. This line of longitude is called the Greenwich meridian.
Objects that are to the east of the Greenwich meridian are the east longitude area, and those to the west are the west longitude area.
East longitudes are considered positive, and west longitudes are considered negative.

With the help of the meridian, such a direction as north-south is determined, and vice versa.

Latitude on a geographical map is measured from the equator - this is zero degrees. At the poles - 90 degrees of geographical latitude.

From what points, what meridian is the geographic longitude measured?

Longitude on a geographical map is measured from Greenwich. The prime meridian is 0°. The farther away from Greenwich an object is, the greater its longitude.

To determine the location of an object, you need to know its geographical latitude and longitude. As mentioned above, latitude shows the distance from the equator to a given object, and longitude shows the distance from Greenwich to the required object or point.

How to measure, find out the geographical latitude and longitude on the world map? Each parallel of latitude is indicated by a specific number - a degree.

Meridians are also indicated by degrees.

Measure, find out the geographical latitude and longitude on the world map

Any point will be located either at the intersection of the meridian and the parallel, or at the intersection of intermediate indicators. Therefore, its coordinates are indicated by specific indicators of latitude and longitude. For example, St. Petersburg is located at the following coordinates: 60° north latitude and 30° east longitude.

As mentioned above, latitude is parallels. To determine it, you need to draw a line parallel to the equator or a nearby parallel.

If the object is located on the parallel itself, then it is easy to determine its location (it was described above).
If the object is between parallels, then its latitude is determined by the nearest parallel from the equator.
For example, Moscow is located north of the 50th parallel. The distance to this object is measured along the meridian and it is equal to 6 °, which means that the geographical latitude of Moscow is 56 °.

An illustrative example of determining the geographical coordinates of latitude on a world map can be found in the following video:

Video: Geographic latitude and geographic longitude. Geographical coordinates

To determine geographic longitude, you need to determine the meridian on which the point is located, or its intermediate value.

For example, St. Petersburg is located on the meridian, the value of which is 30°.
But what if the object is located between the meridians? How to determine its longitude?
For example, Moscow is located east of 30° east longitude.
Now add the number of degrees along the parallel to this meridian. It turns out 8 ° - it means that the geographical longitude of Moscow is 38 ° east longitude.

Another example of determining the geographic coordinates of longitude and latitude on a world map in a video:

Video: Finding latitude and longitude

All parallels and meridians are indicated on any map. What is the maximum value of geographic latitude and longitude? The greatest value of geographical latitude is 90°, and longitude is 180°. The smallest value for latitude is 0° (Equator), and the smallest value for longitude is also 0° (Greenwich Mean Time).

Geographic latitude and longitude of the poles and equator: what is it?

The geographic latitude of the points of the earth's equator is 0 °, the North Pole +90 °, the South -90 °. The longitude of the poles is not determined, since these objects are located on all meridians at once.

Determination of geographic coordinates of latitude and longitude on Yandex and Google maps online

Schoolchildren may need to determine geographic coordinates using maps in real time when doing tests or exams.

It's convenient, fast and simple. The determination of the geographical coordinates of latitude and longitude on Yandex and Google maps online can be done on various services on the Internet.
For example, it is enough to enter the name of an object, city or country, and click on it on the map. The geographical coordinates of this object will appear instantly.
In addition, the resource will show the address of the point being determined.

The online mode is convenient in that you can find out the necessary information here and now.

How to find a place by coordinates on Yandex and Google maps?

If you do not know the exact address of an object, but you know its geographical coordinates, then its location is easy to find on Google or Yandex maps. How to find a place by coordinates on Yandex and Google maps? Do the following:

Go, for example, to the Google map.
Enter a geographic coordinate value in the search box. It is allowed to enter degrees, minutes and seconds (for example 41°24’12.2″N 2°10’26.5″E), degrees and decimal minutes (41 24.2028, 2 10.4418), decimal degrees: (41.40338, 2.17403).
Click "Search", and the object you are looking for on the map will open in front of you.

The result will appear instantly, and the object itself will be marked on the map with a “red drop”.

Finding satellite maps with latitude and longitude coordinates is easy. You just need to enter keywords in the Yandex or Google search box, and the service will instantly give you what you need.

For example, "Satellite maps with latitude and longitude coordinates." Many sites will open with the provision of such a service. Choose any, click on the desired object and determine the coordinates.

Satellite maps - determining the coordinates of latitude and longitude

The Internet gives us great opportunities. If earlier it was necessary to use only a paper map to determine longitude and latitude, now it is enough to have a gadget with a network connection.

Video: Geographical coordinates and determination of coordinates

Globes and maps have a coordinate system. With its help, you can put any object on a globe or map, as well as find it on the earth's surface. What is this system, and how to determine the coordinates of any object on the surface of the Earth with its participation? We will try to talk about this in this article.

Geographic latitude and longitude

Longitude and latitude are geographical concepts that are measured in angular units (degrees). They serve to indicate the position of any point (object) on the earth's surface.

Geographic latitude - the angle between a plumb line at a particular point and the plane of the equator (zero parallel). Latitude in the Southern Hemisphere is called South, while in the Northern Hemisphere it is called North. It can vary from 0 ∗ to 90 ∗ .

Geographic longitude is the angle that is made by the meridian plane at a certain point to the prime meridian plane. If the longitude reading goes east from the initial Greenwich meridian, then it will be eastern longitude, and if it goes west, then it will be western longitude. Longitude values can be from 0 ∗ to 180 ∗ . Most often, on globes and maps, meridians (longitude) are indicated at their intersection with the equator.

How to determine your coordinates

When a person gets into an emergency situation, he must, first of all, be well oriented on the ground. In some cases, it is necessary to have certain skills in determining the geographical coordinates of your location, for example, in order to transfer them to rescuers. There are several ways to do this the handy way. We present the simplest of them.

Determining longitude with a gnomon

If you are traveling, it is best to set your watch to Greenwich Mean Time:

It is necessary to determine when in the given area there will be noon GMT.
Stick a stick (gnomon) to determine the shortest solar shadow at noon.
Detect the minimum shadow cast by the gnomon. This time will be local noon. In addition, this shadow at this time will point due north.
Calculate the longitude of the place where you are from this time.

Calculations are made based on the following:

since the Earth makes a complete revolution in 24 hours, therefore, 15 ∗ (degrees) it will pass in 1 hour;
4 minutes of time will be equal to 1 geographical degree;
1 second of longitude will be equal to 4 seconds of time;
if noon is before 12 noon GMT, you are in the Eastern Hemisphere;
if you spotted the shortest shadow after 12 o'clock GMT, then you are in the Western Hemisphere.

An example of the simplest calculation of longitude: the shortest shadow was cast by the gnomon at 11:36, that is, noon came 24 minutes earlier than at Greenwich. Based on the fact that 4 minutes of time are equal to 1 ∗ longitude, we calculate - 24 minutes / 4 minutes = 6 ∗ . This means that you are in the Eastern Hemisphere at 6* longitude.

How to determine geographic latitude

The determination is made using a protractor and a plumb line. To do this, a protractor is made from 2 rectangular strips and fastened in the form of a compass so that the angle between them can be changed.

The thread with the load is fixed in the central part of the protractor and plays the role of a plumb line.
With its base, the protractor is aimed at the North Star.
From the indicators of the angle between the plumb line of the protractor and its base, 90 ∗ is subtracted. The result is the angle between the horizon and the North Star. Since this star is only 1 ∗ deviated from the axis of the world pole, the resulting angle will be equal to the latitude of the place where you are currently located.

How to determine geographic coordinates

The simplest way to determine geographic coordinates, which does not require any calculations, is this:

Google Maps opens.
Find the exact place there;
- the map is moved with the mouse, zoomed in and out with the mouse wheel
- Find a place by name using the search.
Click on the desired location with the right mouse button. Select the desired item from the menu that opens. In this case, "What's in there?" Geographic coordinates will appear in the search line at the top of the window. For example: Sochi - 43.596306, 39.7229. They indicate the geographical latitude and longitude of the center of this city. So you can determine the coordinates of your street or house.

By the same coordinates, you can see the place on the map. You can't just change these numbers. If you put longitude first and then latitude, you run the risk of being in a different place. For example, instead of Moscow, you will end up in Turkmenistan.

How to determine the coordinates on the map

To determine the geographic latitude of an object, you need to find the nearest parallel to it from the side of the equator. For example, Moscow is located between the 50th and 60th parallels. The closest parallel from the equator is the 50th. To this figure is added the number of degrees of the meridian arc, which is counted from the 50th parallel to the desired object. This number is equal to 6. Therefore, 50 + 6 = 56. Moscow lies on the 56th parallel.

To determine the geographic longitude of an object, find the meridian where it is located. For example, St. Petersburg lies to the east of Greenwich. Meridian, this one is separated from the zero meridian by 30 ∗ . This means that the city of St. Petersburg is located in the Eastern Hemisphere at a longitude of 30 ∗ .

How to determine the coordinates of the geographic longitude of the desired object, if it is located between two meridians? At the very beginning, the longitude of the meridian that is closer to Greenwich is determined. Then, to this value, it is necessary to add such a number of degrees that is the distance between the object and the meridian closest to Greenwich on the arc of the parallel.

Example, Moscow is located east of the meridian 30 ∗ . Between him and Moscow, the arc of the parallel is 8 ∗ . This means that Moscow has east longitude and it is equal to 38 ∗ (E).

How to determine your coordinates on topographic maps? Geodetic and astronomical coordinates of the same objects differ by an average of 70 m. Parallels and meridians on topographic maps are the inner borders of sheets. Their latitude and longitude are written in the corner of each sheet. Sheets of maps of the Western Hemisphere are marked in the northwest corner of the frame "West of Greenwich". On the maps of the Eastern Hemisphere, respectively, there will be a note "East of Greenwich."

Geographic latitude

Geographic latitude is determined using parallels. Latitude can be north (those parallels that are north of the equator) and south (those parallels that lie south of the equator). The value of latitudes is measured in degrees and minutes. Geographic latitude can have values from 0 to 90 degrees.

Rice. 1. Determination of latitudes

Geographic latitude is the length of the arc in degrees from the equator to the given point.

To determine the latitude of an object, you need to find the parallel on which this object is located.

For example, the latitude of Moscow is 55 degrees and 45 minutes north latitude, it is written as follows: Moscow 55 ° 45 "N; New York latitude - 40 ° 43" N; Sydney - 33°52"S

Geographic longitude

Geographic longitude is determined by meridians. Longitude can be western (from 0 meridian west to 180 meridian) and eastern (from 0 meridian east to 180 meridian). Longitudes are measured in degrees and minutes. Geographic longitude can have values from 0 to 180 degrees.

Geographic longitude is the length of the equatorial arc in degrees from the initial meridian (0 degrees) to the meridian of the given point.

The prime meridian is the Greenwich meridian (0 degrees).

Rice. 2. Determination of longitudes

To determine longitude, you need to find the meridian on which the given object is located.

For example, the longitude of Moscow is 37 degrees and 37 minutes of east longitude, it is written as follows: 37 ° 37 "E; longitude of Mexico City - 99 ° 08" W.

Rice. 3. Geographic latitude and geographic longitude

Geographical coordinates

To accurately determine the location of an object on the surface of the Earth, you need to know its geographic latitude and geographic longitude.

Geographical coordinates- quantities that determine the position of a point on the earth's surface using latitudes and longitudes.

For example, Moscow has the following geographic coordinates: 55°45" N and 37°37" E. The city of Beijing has the following coordinates: 39°56′ N 116°24′ E The latitude value is written first.

Sometimes you need to find an object by already given coordinates, for this you must first assume in which hemispheres this object is located.

Bibliography

Main

1. Initial course of geography: Proc. for 6 cells. general education institutions / T.P. Gerasimova, N.P. Neklyukov. – 10th ed., stereotype. – M.: Bustard, 2010. – 176 p.

2. Geography. Grade 6: atlas. – 3rd ed., stereotype. – M.: Bustard, DIK, 2011. – 32 p.

3. Geography. Grade 6: atlas. - 4th ed., stereotype. – M.: Bustard, DIK, 2013. – 32 p.

4. Geography. 6 cells: cont. cards. – M.: DIK, Bustard, 2012. – 16 p.

Encyclopedias, dictionaries, reference books and statistical collections

1. Geography. Modern illustrated encyclopedia / A.P. Gorkin. – M.: Rosmen-Press, 2006. – 624 p.

Materials on the Internet

1. Federal Institute of Pedagogical Measurements ().

2. Russian Geographical Society ().

Geographical coordinates - angular values: latitude (p and longitude K, which determine the position of objects on the earth's surface and on the map, determine the position of a point on the earth's surface or, more broadly, in a geographical shell.

Geographic coordinates are built on the principle of spherical. Similar coordinates are used on other planets, as well as on the celestial sphere Latitude - the angle φ between the local zenith direction and the equatorial plane, measured 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 those close to the equator as low. The length of the day depends on the latitude of the place, as well as on the time of year.

Due to the difference in the shape of the Earth from the ball, the geographical latitude of the points differs somewhat 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 such astronomical instruments as a sextant or gnomon (direct measurement), you can also use GPS or GLONASS systems (indirect measurement). Longitude is the angle λ between the plane of the meridian passing through a given point and the plane of the initial zero meridian, from which is counting the longitude. Longitudes from 0° to 180° east of the prime meridian are called east, to the west - west. Eastern longitudes are considered to be positive, western - negative.

The choice of the zero meridian is arbitrary and depends only on agreement. Now the prime meridian is the Greenwich meridian passing through the observatory in Greenwich, southeast London. The meridians of the observatories of Paris, Cadiz, Pulkovo, etc. were previously chosen as zero. Local time depends on longitude. 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, "altitude above sea level" is usually used, measured from the level of a "smoothed" surface - the geoid. Such a system of three coordinates turns out to be orthogonal, which simplifies a number of calculations. Altitude is also convenient because it is related to atmospheric pressure. Distance from the earth's surface (up or down) is often used to describe a place, but is not a coordinate. In navigation, the center of mass of the vehicle (VG) is chosen as the origin of the coordinate system. The transition of the origin from the inertial coordinate system to the geographic one (ie from O_i to O_g) is carried out based on the values of latitude and longitude. The coordinates of the center of the geographical coordinate system O_g in the inertial one take the following values (when calculated using a spherical model of the Earth):

X_(og)=(R+h) cos(\varphi) cos(Ut+\lambda) Y_(og)=(R+h) cos(\varphi) sin(Ut+\lambda) Z_(og)=(R+ h) sin(\varphi) where R is the radius of the earth, U is the angular velocity of the earth's rotation, h is the height above sea level. The orientation of the axes in the geographic coordinate system (GCS) is selected by the algorithm.

The X-axis (another designation is the E-axis) is the axis directed to the east. The Y-axis (another designation is the N-axis) is the north-facing axis. Axis Z (another designation - axis Up) - an axis directed vertically upwards. The orientation of the trihedron is XYZ, due to the rotation of the earth and the movement of the vehicle, it constantly shifts with angular velocities.

\omega_E=-V_N/R \omega_N=V_E/R+U cos(\varphi) \omega_(Up)=\frac(V_E)(R)tg(\varphi)+U sin(\varphi) The application of the HCS in navigation is the large values of the angular velocity of this system at high latitudes, increasing up to infinity at the pole. Therefore, instead of HCS, a semi-free CS in azimuth is used. A semi-free CS in azimuth differs from HCS in only one equation, which has the form:

\omega_(Up)=Usin(\varphi) Accordingly, the system has the same initial position as the HCS and their orientation also coincides with the only difference that its X_w and Y_w axes are deviated from the corresponding HCS axes by an angle \varepsilon for which the equation is valid

d \varepsilon/dt=-\frac(V_E)(R)tg(\varphi) The conversion between HCS and semi-free CS in azimuth is carried out according to the formula

N=Y_w cos(\varepsilon)+X_w sin(\varepsilon) E=-Y_w sin(\varepsilon)+X_w cos(\varepsilon) coordinates in the GCW. The WGS84 system is used to record geographic coordinates.

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

in ° decimal degrees (modern version) in ° degrees and decimal minutes in ° degrees, "minutes and" decimal seconds (historical notation) The decimal separator is always a period. Positive signs of coordinates are represented by ( in most cases, omitted) by the "+" sign, or by the letters: "N" - north latitude and "E" - east longitude. Negative signs of coordinates are represented either by the "-" sign or by the letters: "S" - south latitude and "W" - West longitude Letters can be either in front or behind.

There are no uniform rules for recording coordinates.

By default, search engine maps show coordinates in degrees with a decimal fraction with "-" signs for negative longitude. On Google maps and Yandex maps, latitude first, then longitude (until October 2012, the reverse order was adopted on Yandex maps: first longitude, then latitude). These coordinates are visible, for example, when laying routes from arbitrary points. The search also recognizes other formats.

By default, navigators often show degrees and minutes with a decimal fraction with a letter designation, for example, in Navitel, in iGO. You can enter coordinates in accordance with other formats. The degrees and minutes format is also recommended for maritime communications. [source not specified 1281 days]

At the same time, the original way of writing with degrees, minutes and seconds is often used. Currently, coordinates can be written in one of many ways or duplicated in two main ways (with degrees and with degrees, minutes and seconds). As an example, the options for recording the coordinates of the sign "Zero kilometer of the roads of the Russian Federation" are 55 ° 45′21 ″ s. sh. 37°37′04″ in. e. (G) (O) (I):

55.755831°, 37.617673° -- degrees N55.755831°, E37.617673° -- degrees (+ additional letters) 55°45.35"N, 37°37.06"E -- degrees and minutes (+ additional letters) 55° 45 "20.9916" N, 37 ° 37 "3.6228" E - degrees, minutes and seconds (+ additional letters) If necessary, the formats can be converted independently: 1 ° = 60 "minutes, 1" minute = 60 "seconds. You can use specialized services.

Geographic longitude and latitude are used to accurately determine the physical location of any object on the globe. The easiest way to find geographic coordinates is to use a geographic map. This method requires some theoretical knowledge for its implementation. How to determine the longitude and latitude is described in the article.

Geographical coordinates

Coordinates in geography are a system in which each point on the surface of our planet is assigned a set of numbers and symbols that allows you to accurately determine the position of this point. Geographical coordinates are expressed in three numbers - this is latitude, longitude and height above sea level. The first two coordinates, that is, latitude and longitude, are most often used in various geographical tasks. The origin of the report in the geographic coordinate system is at the center of the Earth. Spherical coordinates are used to represent latitude and longitude, which are expressed in degrees.

Before considering the question of how to determine longitude and latitude by geography, you should understand these concepts in more detail.

The concept of latitude

The latitude of a particular point on the surface of the Earth is understood as the angle between the equatorial plane and the line connecting this point with the center of the Earth. Through all points on having the same latitude, you can draw a plane that will be parallel to the plane of the equator.

The plane of the equator is the zero parallel, that is, its latitude is 0 °, and it divides the entire globe into the southern and northern hemispheres. Accordingly, the north pole lies on parallel 90° north latitude and the south pole lies on parallel 90° south latitude. The distance that corresponds to 1° when moving along a particular parallel depends on which parallel it is. With increasing latitude when moving north or south, this distance decreases. Thus is 0°. Knowing that the circumference of the Earth at the latitude of the equator has a length of 40075.017 km, we obtain a length of 1 ° along this parallel equal to 111.319 km.

Latitude indicates how far north or south of the equator a given point lies on the Earth's surface.

The concept of longitude

The longitude of a particular point on the surface of the Earth is understood as the angle between the plane passing through this point and the axis of rotation of the Earth, and the plane of the prime meridian. According to the settlement agreement, the meridian is supposed to be zero, which passes through the Royal Observatory in Greenwich, located in the southeast in England. The Greenwich meridian divides the globe into east and

Thus, each line of longitude passes through the north and south poles. The lengths of all meridians are equal and amount to 40007.161 km. If we compare this figure with the length of the zero parallel, then we can say that the geometric shape of the planet Earth is a ball flattened from the poles.

Longitude shows how far west or east of the zero (Greenwich) meridian lies a specific point on Earth. If latitude has a maximum value of 90° (latitude of the poles), then the maximum value of longitude is 180° west or east of the prime meridian. The 180° meridian is known as the international date line.

One can ask an interesting question, the longitude of which points cannot be determined. Based on the definition of the meridian, we get that all 360 meridians pass through two points on the surface of our planet, these points are the south and north poles.

Geographic degree

From the above figures it can be seen that 1 ° on the Earth's surface corresponds to a distance of more than 100 km, both along the parallel and along the meridian. For more accurate coordinates of the object, the degree is divided into tenths and hundredths, for example, they talk about 35.79 north latitude. In this form, information is provided by satellite navigation systems such as GPS.

Ordinary geographical and topographic maps represent fractions of a degree in the form of minutes and seconds. So, each degree is divided into 60 minutes (denoted by 60"), and each minute is divided into 60 seconds (denoted by 60""). Here you can draw an analogy with the representation of the measurement of time.

Getting to know the map

To understand how to determine the geographical latitude and longitude on the map, you must first familiarize yourself with it. In particular, you need to figure out how the coordinates of longitude and latitude are represented on it. First, the top of the map shows the northern hemisphere, the bottom shows the southern. The numbers on the left and right of the edge of the map indicate latitude, and the numbers at the top and bottom of the map are longitude coordinates.

Before you determine the coordinates of latitude and longitude, you must remember that they are presented on the map in degrees, minutes and seconds. Do not confuse this system of units with decimal degrees. For example, 15" = 0.25°, 30" = 0.5°, 45"" = 0.75".

Using a geographic map to determine longitude and latitude

Let us explain in detail how to determine longitude and latitude by geography using a map. To do this, you first need to purchase a standard geographic map. This map can be a map of a small area, region, country, continent, or the whole world. To understand which card to deal with, you should read its name. At the bottom, under the name, the limits of latitudes and longitudes, which are presented on the map, can be given.

After that, you need to select some point on the map, some object that needs to be marked in some way, for example, with a pencil. How to determine the longitude of an object located at a selected point, and how to determine its latitude? The first step is to find the vertical and horizontal lines that lie closest to the selected point. These lines are the latitude and longitude, the numerical values of which can be viewed at the edges of the map. Assume that the chosen point lies between 10° and 11° north latitude and 67° and 68° west longitude.

Thus, we know how to determine the geographic latitude and longitude of the object selected on the map with the accuracy that the map provides. In this case, the accuracy is 0.5°, both in latitude and longitude.

Determination of the exact value of geographical coordinates

How to determine the longitude and latitude of a point more precisely than 0.5 °? First you need to find out what scale the map with which you are working is. Usually, a scale bar is indicated in one of the corners of the map, showing the correspondence of distances on the map to distances in geographical coordinates and in kilometers on the ground.

After the scale bar is found, it is necessary to take a simple ruler with millimeter divisions and measure the distance on the scale bar. Let in this example, 50 mm corresponds to 1 ° latitude and 40 mm - 1 ° longitude.

Now we position the ruler so that it is parallel to the lines of longitude drawn on the map, and measure the distance from the point in question to one of the nearest parallels, for example, the distance to the 11 ° parallel is 35 mm. We make up a simple proportion and find that this distance corresponds to 0.3 ° from the 10 ° parallel. Thus, the latitude of the point under consideration is +10.3° (the plus sign means north latitude).

Similar actions should be done for longitude. To do this, place the ruler parallel to the lines of latitude and measure the distance to the nearest meridian from the selected point on the map, for example, this distance is 10 mm to the meridian of 67 ° west longitude. According to the rules of proportion, we obtain that the longitude of the object in question is -67.25 ° (the minus sign means longitude west).

Convert received degrees to minutes and seconds

As stated above, 1° = 60" = 3600"". Using this information and the rule of proportion, we find that 10.3° corresponds to 10°18"0"". For the longitude value, we get: 67.25 ° = 67 ° 15 "0"". In this case, the proportion was used once for the longitude and latitude for the conversion. However, in the general case, when fractional minutes are obtained after using the proportion once, it follows use the proportion a second time to get the value of incremental seconds. Note that the accuracy of determining the coordinates to 1 "corresponds to an accuracy on the surface of the globe equal to 30 meters.

Recording received coordinates

After the question of how to determine the longitude of an object and its latitude has been resolved, and the coordinates of the selected point have been determined, they should be written down correctly. The standard notation is to indicate the longitude after the latitude. Both values must be specified with as many decimal places as possible, since the accuracy of the object location depends on this.

Certain coordinates can be represented in two different formats:

Using only the degree icon, e.g. +10.3°, -67.25°.
Using minutes and seconds, for example, 10°18"0"" North, 67°15"0"" West.

It should be noted that when representing geographic coordinates in degrees only, the words "North (South) latitude" and "East (West) longitude" are replaced by the appropriate plus or minus sign.