What is the geographical latitude and longitude of an object: explanation and determination of the geographical coordinates of latitude and longitude on the world map, Yandex and Google map online. From what points geographic latitude and longitude are measured

Every place on earth can be identified by a global latitude and longitude coordinate system. Knowing these parameters, it is easy to find any location on the planet. The coordinate system has been helping people in this for several centuries in a row.

Historical preconditions for the emergence of geographic coordinates

When people began to travel long distances through deserts and seas, they needed a way to fix their position and know in which direction to move so as not to get lost. Before latitude and longitude appeared on the map, the Phoenicians (600 BC) and Polynesians (400 AD) used the starry sky to calculate latitude.

Over the centuries, quite sophisticated devices have been developed such as the quadrant, astrolabe, gnomon, and Arabian kamal. They were all used to measure the height of the sun and stars above the horizon and thereby measure latitude. And if the gnomon is just a vertical stick that casts a shadow from the sun, then the kamal is a very peculiar device.

It consisted of a 5.1 x 2.5 cm rectangular wooden plank, to which a rope with several equally spaced knots was attached through a hole in the middle.

These instruments were used to determine latitude even after their invention until a reliable method for determining latitude and longitude on a map was invented.

Navigators for hundreds of years did not have an accurate idea of the location due to the lack of a concept of the value of longitude. There was no exact time device in the world, such as a chronometer, so calculating longitude was simply impossible. Not surprisingly, early navigation was problematic and often resulted in shipwrecks.

No doubt the pioneer of revolutionary navigation was Captain James Cook, who traveled across the Pacific Ocean thanks to the technical genius Henry Thomas Harrison. In 1759, Harrison developed the first navigational clock. By keeping accurate Greenwich Mean Time, Harrison's watch allowed sailors to determine how many hours were at a point and at a location, after which it became possible to determine the longitude from east to west.

Geographic coordinate system

A geographic coordinate system defines two-dimensional coordinates based on the surface of the earth. It has an angular unit of measure, a prime meridian and an equator with latitude zero. The globe is conventionally divided into 180 degrees of latitude and 360 degrees of longitude. Latitude lines are placed parallel to the equator and are horizontal on the map. Longitude lines connect the North and South Poles and are vertical on the map. As a result of the overlay, geographical coordinates are formed on the map - latitude and longitude, with which you can determine the position on the surface of the Earth.

This geographic grid gives a unique latitude and longitude for every position on Earth. To improve the accuracy of measurements, they are further subdivided into 60 minutes, and each minute into 60 seconds.

The Equator is located at right angles to the Earth's axis, roughly halfway between the North and South Poles. At 0 degrees, it is used in the geographic coordinate system as the starting point for calculating latitude and longitude on a map.

Latitude is defined as the angle between the equatorial line of the center of the Earth and the location of its center. The North Pole and South Pole have a width angle of 90. To distinguish places in the Northern Hemisphere from the Southern Hemisphere, width is additionally provided in the traditional spelling with N for north or S for south.

The earth is tilted by about 23.4 degrees, so to find the latitude at the summer solstice you need to add 23.4 degrees to the angle you are measuring.

How to determine latitude and longitude on a map during the winter solstice? To do this, subtract 23.4 degrees from the angle that is being measured. And in any other period of time, you need to determine the angle, knowing that it changes by 23.4 degrees every six months and, therefore, about 0.13 degrees per day.

In the northern hemisphere, you can calculate the angle of the Earth's tilt, and therefore latitude, by looking at the angle of the North Star. At the North Pole, it will be 90 degrees from the horizon, and at the equator, it will be directly in front of the observer, 0 degrees from the horizon.

Important latitudes:

North and South polar circles, each is located at 66 degrees 34 minutes north and, respectively, south latitude. These latitudes limit the areas around the poles where the sun does not set at the summer solstice, so the midnight sun prevails there. On the winter solstice, the sun does not rise here, the polar night sets in.
Tropics are located at 23 degrees 26 minutes in the north and south latitudes. These latitudinal circles mark the solar zenith with the summer solstice of the northern and southern hemispheres.
Equator lies at latitude 0 degrees. The equatorial plane runs roughly in the middle of the Earth's axis between the north and south poles. The equator is the only circle of latitude that corresponds to the circumference of the earth.

Latitude and longitude on a map are important geographic coordinates. Longitude is much more difficult to calculate than latitude. The earth rotates 360 degrees a day, or 15 degrees an hour, so there is a direct relationship between longitude and the time the sun rises and falls. The Greenwich meridian is indicated by 0 degree longitude. The sun sets an hour earlier every 15 degrees east of that and an hour later every 15 degrees west. Knowing the difference between the time of sunset of a location and another known location can tell you how far east or west is from that location.

Longitude lines run from north to south. They converge at the poles. And the longitude coordinates are between -180 and +180 degrees. The Greenwich meridian is the zero line of longitude, which measures the east-west direction in a geographic coordinate system (such as latitude and longitude on a map). In fact, the zero line passes through the Royal Observatory in Greenwich (England). Greenwich meridian as the zero is the starting point for calculating longitude. Longitude is specified as the angle between the center of the prime meridian of the center of the Earth and the center of the center of the Earth. The Greenwich meridian has an angle of 0, and the opposite longitude, along which the date line runs, has an angle of 180 degrees.

How to find latitude and longitude on a map?

Determining the exact geographic location on a map depends on its scale. To do this, it is enough to have a map with a scale of 1/100000, or better - 1/25000.

First, longitude D is determined by the formula:

D = G1 + (G2 - G1) * L2 / L1,

where G1, G2 - the value of the right and left nearest meridians in degrees;

L1 is the distance between these two meridians;

Calculation of longitude, for example, for Moscow:

G1 = 36 °,

G2 = 42 °,

L1 = 252.5 mm,

L2 = 57.0 mm.

The sought longitude = 36 + (6) * 57.0 / 252.0 = 37 ° 36 ".

Determine the latitude L, it is determined by the formula:

L = G1 + (G2 - G1) * L2 / L1,

where G1, G2 - the value of the lower and upper nearest latitude in degrees;

L1 is the distance between these two latitudes, mm;

L2 - distance from the definition point to the nearest left.

For example, for Moscow:

L1 = 371.0 mm,

L2 = 320.5 mm.

The sought width L = 52 "+ (4) * 273.5 / 371.0 = 55 ° 45.

We check the correctness of the calculation, for this we need to find the coordinates of latitude and longitude on the map using online services on the Internet.

We establish that the geographical coordinates for Moscow correspond to the calculations performed:

55 ° 45 "07" (55 ° 45 "13) north latitude;
37 ° 36 "59" (37 ° 36 "93) east longitude.

Determining the coordinates of a location using an iPhone

The acceleration of the pace of scientific and technological progress at the present stage has led to revolutionary discoveries of mobile technology, with the help of which a quick and more accurate determination of geographic coordinates has become available.

There are various mobile applications for this. On iPhones, this is very easy to do using the Compass app.

Determination procedure:

To do this, click "Settings" and then - "Privacy".
Now click on Location Services at the very top.
Scroll down until you see the compass and touch it.
If you see that it says "When used on the right side", you can start defining.
If not, tap it and select "While using an app."
Open the Compass app and you will see your current location and current GPS coordinates at the bottom of the screen.

Finding coordinates in an Android phone

Unfortunately Android doesn't have an official built-in way to get GPS coordinates. However, it is possible to get Google Maps coordinates, which requires some additional steps:

Open Google Maps on your Android device and search for the desired definition point.
Press and hold it anywhere on the screen and drag it to Google Maps.
An informational or detailed map will appear at the bottom.
Find the Share option on the info card in the upper right corner. This will bring up a menu with the Share option.

This setting can be done in Google Maps on iOS.

This is a great way to get coordinates and does not require installing any additional applications.

Video tutorial “Geographic latitude and geographic longitude. Geographic Coordinates ”will help you get an idea of the geographic latitude and geographic longitude. The teacher will tell you how to correctly determine the geographic coordinates.

Geographic latitude- arc length in degrees from the equator to a given point.

To determine the latitude of an object, you need to find the parallel to which the 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 is determined by the meridians. Longitude can be western (from 0 meridian west to 180 meridian) and east (from 0 meridian east to 180 meridian). Longitudes are measured in degrees and minutes. Geographic longitude can range from 0 to 180 degrees.

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

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

Rice. 2. Determination of longitudes ()

To determine the 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 east longitude, it is written like this: 37 ° 37 "east longitude; longitude of Mexico City - 99 ° 08" west longitude.

Rice. 3. Geographic latitude and geographic longitude

To accurately determine the location of an object on the surface of the Earth, you need to know its 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 geographical coordinates: 55 ° 45 "north latitude and 37 ° 37" east longitude. The city of Beijing has the following coordinates: 39 ° 56 ′ N. 116 ° 24 ′ E The latitude value is recorded first.

Sometimes it is required to find an object according to already specified coordinates, for this you must first assume in which hemispheres this object is located.

Homework

Paragraphs 12, 13.

1. What is latitude and longitude?

Bibliography

The main

1. An initial course in geography: Textbook. for 6 cl. general education. institutions / T.P. Gerasimova, N.P. Neklyukova. - 10th ed., Stereotype. - M .: Bustard, 2010 .-- 176 p.

2. Geography. 6th grade: atlas. - 3rd ed., Stereotype. - M .: Bustard, DIK, 2011 .-- 32 p.

3. Geography. 6th grade: atlas. - 4th ed., Stereotype. - M .: Bustard, DIK, 2013 .-- 32 p.

4. Geography. 6 cl .: cont. cards. - M .: DIK, Bustard, 2012 .-- 16 p.

Encyclopedias, dictionaries, reference books and statistical compilations

1. Geography. Modern Illustrated Encyclopedia / A.P. Gorkin. - M .: Rosmen-Press, 2006 .-- 624 p.

Literature for preparing for the State Examination and the Unified State Exam

1. Geography: initial course. Tests. Textbook. manual for students of 6 cl. - M .: Humanit. ed. center VLADOS, 2011 .-- 144 p.

2. Tests. Geography. 6-10 grades: Study guide / A.A. Letyagin. - M .: OOO "Agency" KRPA "Olymp": "Astrel", "AST", 2001. - 284 p.

Materials on the Internet

1. Federal Institute for Pedagogical Measurements ().

2. Russian Geographical Society ().

Latitude φ is the angle between plumb line at a given point and by the plane of the equator, measured from 0 to 90 ° on both sides of the equator.

The term "plumb line" means the direction towards the center of gravity ("astronomical latitude") or perpendicular to the surface at a given point ("geodetic latitude"). In the latter case, the "surface" is usually understood as the surface of an ellipsoid approximating the shape of the Earth. In practice, the differences are usually small - for example, in the WGS 84 system used in GPS receivers, the geometric center of the model is assumed to be no more than 2 centimeters from the Earth's center of gravity.

The concept of latitude

First, let's define what latitude is. In geography, it is understood as the angle formed by a straight line passing through a given point on the surface of the planet and through its center with the equatorial plane. According to this definition, the apex of the angle that determines the geographic latitude is located in the center of our planet, through which the equatorial plane also passes. If, without changing this angle, you rotate the straight line connecting the center and a point on the surface around an axis perpendicular to the equator, then the straight line will draw a circle on the surface of the Earth. As you might guess, all points of this circle will have the same latitude. This circle is called a parallel.

Knowing the definition of what latitude is, we can safely say that this value is measured in degrees. Since the maximum value of the angle between a straight line and a plane is 90 o, this figure shows the greatest value of latitude (it corresponds to the poles of our planet). The smallest latitude (0 o) is the point on the equatorial circle.

How is latitude recorded?

Since the Earth is spherical (geoid, to be precise), the equator divides it into two equal hemispheres. The upper one is called the northern one, and the lower one is called the southern one. This fact is taken into account when recording the coordinates of the geographical latitude. It should also be recalled that geographic degrees are expressed in the sexagesimal system, that is, the whole circle is 360 o, 1 o is 60 "(minutes), and 1" includes 60 "" (seconds). There are two ways to represent latitude coordinates:

Use of "+" and "-" signs, the first of which corresponds to the northern hemisphere, the second to the southern. For example, the numbers 22 o 45 "11" "mean 22 degrees 45 minutes and 11 seconds north.
Adding the Latin letters N (north) or S (south). The entry 22 o 45 "11" "N defines the same latitude as in the example above. In Russian maps, the letters" C "and" U "can be used for the northern and southern hemispheres, respectively.

It is curious to give the value of the distance on the surface of the planet, which corresponds to 1 o latitude. It is not constant because the Earth is flattened from the poles. So, at the latitude of the equator 1 o = 110.57 km, near the poles 1 o = 111.70 km. Usually, the average value of this value is used, it is 111.12 km. One minute from the last value is equal to 1852 meters and is called a nautical mile. One second of latitude is on average 30 m 86 cm.

Important parallels

Due to the round shape of our planet, the sun's rays fall on it from different angles. Moreover, the magnitude of the angle of incidence is uniquely determined by the geographic latitude. Where the sun's rays fall at right angles to the surface, the earth, air and water are warmed up more. This situation is typical for low latitudes. On the contrary, small angles of incidence of rays lead to the fact that solar energy practically does not enter the given area, this is observed in high latitudes. Thanks to the described fact, 4 important parallels are distinguished, which form 3 climatic zones on the planet:

The Tropic of Cancer (23 o 26 "14" "N) and the Tropic of Capricorn (23 o 26" 14 "" S) border the tropical climate zone.
The parallels 66 o N and 66 o S are called the North and South Polar Circle, respectively. Together with the tropics, they form a temperate zone in both hemispheres.
Cold polar belts lie between 66 o and 90 o of each hemisphere.

Longitude concept

After getting to know the question of what latitude is, let's move on to determining longitude. Geographic longitude is an angle that is described by the following three points:

Its top is located on the axis of the Earth, perpendicular to the plane of the equator.
The point on the surface that is the assumed reference origin.
The point on the terrain, the longitude of which is determined.

All the named points lie in the same plane, that is, at the same latitude (two on the surface and one in the center of the Earth on its axis). The illustration in the first paragraph of the article will help you understand the concept of longitude.

In this definition, an important point is the choice of the reference point. At present, the longitude at which the Greenwich Observatory (London, England) is located is considered to be such throughout the world; the value of 0 o is attributed to it. Note that different nations prior to the 19th century used their own zero longitude. For example, the Spaniards considered such an observatory in the city of Cadiz, and the French - an observatory in Paris.

What is a meridian?

When talking about latitude and longitude, many people think of parallels and meridians. The first has already been defined in the article. As for the meridian, it is understood as a line that connects the points of the north and south poles. Thus, all meridians are of the same length and they intersect the parallels at right angles.

The idea of introducing a meridian is associated not only with the concept of longitude, but also with the time of day. Its name has Latin roots and means the middle of the day. Due to the rotation of the Earth around its axis, the Sun crosses all the meridians of our planet during the day as a result of its apparent movement across the sky. This fact allows us to introduce the concept of time zones, each of which occupies a strip 15 o (360 o / 24 hours) wide.

Longitude recording

If we return again to the definition of longitude, then in order to describe all points on a particular parallel, it is necessary to make a revolution of 360 o. It is customary to describe longitude in the following ways:

One digit when moving east of the prime meridian (Greenwich Observatory). In this case, the longitude varies from 0 o to 360 o.
From 0 o to 180 o with indication of hemisphere (western (W or W) or eastern (B or E)).
From 0 o to 180 o, using the signs "+" for the eastern hemisphere and "-" for the western hemisphere.

Thus, records of longitude 270 o, -90 o and 90 o W (90 o W) are equivalent.

Geographical coordinates

Thus, in order to determine the position of an object on the ground, it is necessary to know its latitude and longitude coordinates. Here is a simple problem: it is necessary to determine the coordinates of the capital of Russia, Moscow.

To solve the problem, we will use a map that shows the corresponding meridians and parallels. Below is an example of such a map, with which you can roughly determine the latitude and longitude of Moscow (Moscow).

The map shows that Moscow lies below 60 o N, given the scale, we can say that its latitude is near 56 o N. As for the longitude, it can be seen that the city lies to the right of 30 o E. Given the scale, we get about 38 o E. Thus, the coordinates of the capital of Russia are approximately equal to 56 o N 38 o E (or in the Russian version 56 o C 38 o B). If you use a more accurate map, you can determine that the latitude and longitude of Moscow are 55 o 45 "N and 37 o 37" E.

Historical reference

Although the given definitions of the geographical coordinates of latitude and longitude are quite simple, in practice their measurement is a difficult task.

Until the 18th century, sailors could more or less accurately determine only the latitude, thanks to the measurement of the angle above the horizon of the North Star. As for the longitude, it was determined only approximately, using primitive tools, for example, a rope with knots for calculating the speed of a ship and an hourglass. Only with the invention of the chronometer at the end of the 18th century, mariners were able to determine the longitude of their location with good accuracy.