Latitude- angle φ between the local direction of the zenith and the plane of the equator, 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 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 equatorial plane.
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 angleλ 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 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 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 disadvantage in practical application G.S.K. 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 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.
The ability to determine where the latitude or longitude is on the map is important for a person. Especially when there was an accident and you need to quickly make a decision and transfer the coordinates to the police. She is recognized in a variety of ways. They mean the angle that is a vertical line and 0 parallel at a predetermined point. The value is only up to 90 degrees.
Do not forget that the equator divides the earth into northern and southern hemispheres. Therefore, the latitude of earthly points that are higher than the longest parallel are northern, and if they are located below, then southern.
How to find out the latitude of any object?
You can determine the latitude and longitude on the map. Look at which parallel the object is marked. If it is not specified, then independently calculate the distance between neighboring lines. Then find the degree of parallel you are looking for.
At the equator, geographic latitude is 0°. Points that are on the same parallel will have the same latitude. If you take a map, you will see it on the frames, if a globe, then where the parallels intersect with 0° and 180° meridians. Geographic latitudes range from 0° and only up to 90° (near the poles).
5 major latitudes
Take a map, there you will see the main parallels. Thanks to them, the coordinates are easier to recognize. From the latitudinal line to the line, territories are located. They belong to one of the areas: temperate or equatorial, arctic or tropics.
The equator is the longest parallel. Lines that are lower or higher decrease towards the poles. The latitude of the equator is 0°. This is the point from which the parallels are counted towards the south or north. The area that starts from the equator and stretches to the tropics is the equatorial region. Tropic north - the main parallel. It is always marked on the maps of the world.
You can find the exact coordinates of 23° 26 min. and 16 sec. north of the equator. This parallel is also called the Tropic of Cancer. Tropic South is a parallel located at 23° 26 min. and 16 sec. south of the equator. It is called the Tropic of Capricorn. The area that is located in the middle of the line and to the equator are tropical regions.
At 66° 33 min. and 44 sec. Just above the equator is the Arctic Circle. This is the border, beyond it the duration of the night increases. Near the pole it is 40 calendar days.
Latitude of the Antarctic Circle -66° 33 min. and 44 sec. And this is the border, and beyond it there are polar days and nights. The regions between the tropics and the described lines are temperate, and those beyond them are called polar.
Instruction
Step #1
Everyone knows that the equator divided the earth into southern and northern hemispheres. In addition to the equator, there are parallels. These are circles that are parallel to the equator itself. Meridians are conditional lines that are perpendicular to the equator.
The zero meridian passes through the observatory, it is called the Greenwich observatory and it is located in London. That's why they say so: "Greenwich Meridian". The system, which includes parallels with meridians, creates a grid of coordinates. It is used when they want to determine where an object is located.
Step #2
Geographic latitude shows given point south or north of the equator? It defines the angle 0° and to 90°. The angle begins to count from the equator and to the south or north pole. So you can determine the coordinates, they say that the latitude is southern or northern.
Step #3
Geographic coordinates are measured in minutes with seconds, and most importantly - in degrees. A degree of a certain latitude is 1/180 of any of the meridians. The average length of 1 degree is 111.12 km. A minute in length is 1852 m. The diameter of Mother Earth is 12713 km. This is the distance from pole to pole.
Step #4
To find out latitude 1 in the described way, you need a plumb line with a protractor. You can make a protractor yourself. Take a few rectangular planks. Fasten them like compasses so that they change the angle between them.
Step #5
Take the thread. Hang a load (plumb) on it. Anchor the thread in the center of your protractor. Point the base of the protractor at the polar star. Do some geometric calculations. Specifically, from the angle that is between the plumb line and the base of your protractor, immediately subtract 90 °. This result is the angle that passes between the polar star and the horizon. This angle is the geographic latitude where you are.
Another way
There is another option, how you can find the coordinates. It doesn't look like the first one. Wake up before sunrise and spot its beginning, and then the sunset. Pick up a monogram to find the latitude. On the left of the monogram, set aside how long the daylight hours lasted, and write the date on the right.
Even in the middle of the XVIII century. such coordinates could be learned on the basis of astronomical observations. In the 20s. The 20th century can already be contacted by radio and determine the coordinates with special tools.
Geographic longitude and latitude are used to accurately determine the physical location of any object on the globe. by the most in a simple way finding 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 geometric shape 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. Meridian 180° is known as international line date changes.
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 southern and north pole.
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 must first purchase a standard geographical 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 arrange the ruler so that it is parallel lines 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 west longitude).
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 the accuracy on the surface 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 much as possible a large number decimal places, since the accuracy of the location of the object 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.
Video lesson “Geographical latitude and geographical longitude. Geographical coordinates" will help you get an idea of the geographic latitude and geographic longitude. The teacher will tell you how to correctly determine the geographical coordinates.
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 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- length of the arc of the equator 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. Definition 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; the longitude of Mexico City is 99 ° 08" W.
Rice. 3. Geographic latitude and geographic longitude
To accurately determine the location of an object on the surface of the Earth, it is necessary 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.
Homework
Paragraphs 12, 13.
1. What is geographic latitude and longitude?
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.
Literature for preparing for the GIA and the Unified State Examination
1. Geography: initial course. Tests. Proc. allowance for students 6 cells. - M.: Humanit. ed. center VLADOS, 2011. - 144 p.
2. Tests. Geography. 6-10 cells: Teaching aid/ A.A. Letyagin. - M .: LLC "Agency" KRPA "Olimp": "Astrel", "AST", 2001. - 284 p.
Materials on the Internet
1. Federal Institute of Pedagogical Measurements ().
2. Russian Geographic Society ().
It is possible to determine the location of a point on the planet Earth, as well as on any other spherical planet, using geographical coordinates - latitude and longitude. Right-angled intersections of circles and arcs create a corresponding grid, which makes it possible to uniquely determine the coordinates. A good example is an ordinary school globe lined with horizontal circles and vertical arcs. How to use the globe will be discussed below.
This system is measured in degrees (degree angle). The angle is calculated strictly from the center of the sphere to a point on the surface. Relative to the axis, the degree of the angle of latitude is calculated vertically, longitude - horizontally. To calculate the exact coordinates, there are special formulas, where one more value is often found - the height, which serves mainly to represent three-dimensional space and allows you to make calculations to determine the position of a point relative to sea level.
Latitude and longitude - terms and definitions
The earth's sphere is divided by an imaginary horizontal line into two equal parts of the world - the northern and southern hemispheres - into the positive and negative poles, respectively. This is how the definitions of northern and southern latitudes are introduced. Latitude is represented as circles parallel to the equator, called parallels. The equator itself with a value of 0 degrees is the starting point for measurements. The closer the parallel is to the upper or lower pole, the smaller its diameter and the higher or lower the angular degree. For example, the city of Moscow is located at 55 degrees north latitude, which determines the location of the capital as approximately equidistant from both the equator and the north pole.
Meridian - the so-called longitude, represented as a vertical arc strictly perpendicular to the circles of the parallel. The sphere is divided into 360 meridians. The starting point is the zero meridian (0 degrees), the arcs of which pass vertically through the points of the northern and south poles and spread to the east and west. In this way, the angle of longitude is determined from 0 to 180 degrees, calculated by values from the center to extreme points to the east or south.
Unlike latitude, whose reference point is the equatorial line, any meridian can be zero. But for convenience, namely the convenience of counting time, the Greenwich meridian was determined.
Geographic coordinates - place and time
Latitude and longitude allow you to assign to a particular place on the planet an exact geographical address, measured in degrees. Degrees, in turn, are divided into smaller units, such as minutes and seconds. Each degree is divided into 60 parts (minutes), and each minute is divided into 60 seconds. On the example of Moscow, the record looks like this: 55° 45′ 7″ N, 37° 36′ 56″ E or 55 degrees, 45 minutes, 7 seconds north latitude and 37 degrees, 36 minutes, 56 seconds south longitude.
The interval between the meridians is 15 degrees and about 111 km along the equator - this is the distance the Earth rotates in one hour. It takes 24 hours for a full turn, which is a day.
Use the globe
The model of the Earth is accurately reproduced on a globe with a realistic rendering of all continents, seas and oceans. As auxiliary lines, parallels and meridians are drawn on the map of the globe. Almost any globe has in its design a crescent-shaped meridian, which is installed on the base and serves as an auxiliary measure.
The meridian arc is equipped with a special degree scale, which determines the latitude. Longitude can be found using another scale - a hoop, horizontally installed at the level of the equator. Marking the desired place with your finger and rotating the globe around its axis to the auxiliary arc, we fix the latitude value (depending on the location of the object, it will turn out to be either north or south). Then we mark the data of the equator scale at the place of its intersection with the meridian arc and determine the longitude. To find out whether it is east or south longitude, you can only relative to the zero meridian.
