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Why do we need geographic coordinates. Geographic coordinates Where and what coordinates are used for

Measured from 0° to 90° either side 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 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.

Longitude

Longitude- the 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. 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.

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, the "height above sea level" is usually used, measured 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.

The distance from the earth's surface (up or down) is often used to describe a location, however not serves coordinate

Geographic coordinate system

The main drawback in the practical application of the HCS 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 HCS, a semi-free CS in azimuth is used.

Semi-free in azimuth coordinate system

The semi-free in azimuth SC differs from the HSC in only one equation, which has the form:

Accordingly, the system has the same initial position that the HCS and their orientation also coincide with the only difference that its axes and are deviated from the corresponding axes of the HCS by an angle for which the equation is valid

The conversion between the HCS and semi-free in the azimuth of the CS is carried out according to the formula

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

The WGS84 system is used to record geographic coordinates.

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

in ° degrees as a decimal fraction (modern version)
in ° degrees and "minutes with decimals
in ° degrees, " minutes and " seconds with a decimal fraction (historical notation)

The decimal separator is always a dot. Positive signs of coordinates are represented by the (in most cases, omitted) sign "+", or by the letters: "N" - north latitude and "E" - east longitude. Negative signs of coordinates are represented either by a "-" sign or by the letters: "S" - southern latitude and "W" - western longitude. Letters can stand both in front and 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.

In navigators, by default, degrees and minutes are more often shown 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.

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" - 55.755831 , 37.617673 55°45′20.99″ N sh. 37°37′03.62″ E d. / 55.755831 , 37.617673 (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)

Notes

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See what "Geographic coordinates" are in other dictionaries:

Geographical coordinates- see Coordinates. Mountain Encyclopedia. M.: Soviet Encyclopedia. Edited by E. A. Kozlovsky. 1984 1991 ... Geological Encyclopedia

GEOGRAPHICAL COORDINATES- (latitude and longitude), determine the position of a point on the earth's surface. Geographical latitude j is the angle between the plumb line at a given point and the plane of the equator, counted from 0 to 90 degrees on both sides of the equator. Geographic longitude l angle ... ... Modern Encyclopedia

GEOGRAPHICAL COORDINATES- latitude and longitude, determine the position of a point on the earth's surface. Geographic latitude? the angle between the plumb line at a given point and the plane of the equator, counted from 0 to 90. in both directions from the equator. Geographic longitude? angle between ... ... Big Encyclopedic Dictionary

Geographical coordinates- angular values that determine the position of a point on the Earth's surface: latitude - the angle between the plumb line at a given point and the plane of the earth's equator, measured from 0 to 90 ° (north latitude north of the equator and south latitude south); longitude ... ... Marine dictionary

The answer to this question became obvious to me when I got lost in the taiga forests of Siberia. I'll tell you what are the coordinates for What is it and how did I find it.

The need for coordinates

Coordinates needed to don't get lost or something find...

Coordinates can be any objects or directions in space. For example, my place of residence is the village of Mikhailovsky. But there are such villages in every region of Russia. It would be more accurate to indicate the region, for example, Moscow. You will say: "There are several such villages in the Moscow region." Then you need to know the region. For example, Solnechnogorsky. So, you have already found the village, but not me. I must also be found in the settlement.

The region, district and village are approximate, not exact coordinates my place of residence. But knowing the geographical coordinates will help you find me much faster. Geographical coordinates indicated on the margins of any more or less accurate map of the region and in modern telephone devices, delighted with navigation systems.

Geographical coordinates

Geographical coordinates are numbers that show your place in a room, city, country or ocean. Geographic coordinates are defined by three parameters:

Latitude- a change in the position of an object in the direction from the equator to any geographic pole. The latitude is north (we move from the equator to Antarctica) and south (we move from the equator to the Arctic). Latitude is an angular value, measured in degrees.
Longitude- change in the position of the object in the direction from the zero meridian towards Asia (east longitude) or America (west longitude). It is measured, like latitude, in degrees.
Height or depth- change in the position of an object up or down (in depth) from the surface of the oceans. It is measured in meters with a negative or positive value. A negative value indicates that the object is at a depth below the level of the world's oceans.

... And I found it very simply: I reported my coordinates to the camp of the geological expedition. I determined the coordinates on topographic map(they are written in the margins), according to two landmarks - lakes and settlements, which I went to in turn.

With such concepts as longitude and latitude, many of us met in childhood thanks to the adventure novels of Stevenson and Jules Verne. People have been studying these concepts since ancient times.

In an era when perfect navigational instruments did not exist in the world, it was the geographical coordinates on the map that helped sailors determine their location in the sea and find their way to the desired land areas. Today, latitude and longitude are still used in many sciences and allow you to accurately determine the position of any point on the earth's surface.

What is latitude?

Latitude is used to set the location of an object relative to the poles. At the same distance from and passes the main imaginary line of the globe - the equator. It has zero latitude, and parallels stretch on both sides of it - similar imaginary lines that conditionally cross the planet at regular intervals. To the north of the equator are the northern latitudes, to the south, respectively, the southern ones.

The distance between the parallels is usually measured not in meters or kilometers, but in degrees, which allows you to more accurately determine the position of the object. There are 360 degrees in total. Latitude is measured north of the equator, that is, points lying in the Northern Hemisphere have a positive latitude, and those located in the Southern Hemisphere have a negative one.

For example, the north pole lies at a latitude of +90°, the south pole at -90°. Additionally, each degree is divided into 60 minutes, and minutes into 60 seconds.

What is longitude?

To find out the location of an object, it is not enough to know this place on the globe relative to the south or north. In addition to latitude, longitude is used for a complete calculation, which sets the position of the point relative to east and west. If in the case of latitude the equator is taken as the basis, then longitude is calculated from the zero meridian (Greenwich), passing from the North to the South Pole through the London area of Greenwich.

On the right and left sides of the Greenwich meridian, ordinary meridians are drawn parallel to it, which meet each other at the poles. East longitude is considered positive, and west longitude is negative.

Like latitude, longitude has 360 degrees divided into seconds and minutes. To the east of Greenwich is Eurasia, to the west - South and North America.

What are latitude and longitude for?

Imagine that you are sailing on a ship lost in the middle of the ocean, or moving through the endless desert, where there are no signs and indicators at all. How could you explain your location to rescuers? It is latitude and longitude that help to find a person or other object anywhere in the world, wherever he is.

Geographic coordinates are actively used on search engine maps, in navigation, on conventional geographical maps. They are present in geodetic instruments, satellite positioning systems, GPS navigators and other tools needed to determine the location of a point.

How to set geographic coordinates on the map?

To calculate the coordinates of an object on the map, you must first determine in which of the hemispheres it is located. Next, you should find out between which parallels the desired point is located, and set the exact number of degrees - usually they are written on the sides of the geographical map. After that, you can proceed to the determination of longitude, first establishing in which of the hemispheres the object is located relative to Greenwich Mean Time.

Determination of degrees of longitude is carried out similarly to latitude. If you need to find out the location of a point in three-dimensional space, its height relative to sea level is additionally used.

Project of 6th grade students under the guidance of mathematics teacher Anisimova Zoya Ilyinichna

Leave me your coordinates."

Everything in this life is easy to find: someone's house, office, flowers and mushrooms,

A place in the theater, in the classroom your table, you just learn the coordinate law.

Brief summary of the project:

Material on the topic "Coordinate plane" is studied in the 6th grade mathematics course. 4 hours are allotted for the study of the topic. This topic falls on time at the end of April - beginning of May, when the teacher and children are loaded with work at the end of the school year. The ability to navigate well in the coordinate plane is important for subsequent work on the topic "Graphics", so 4 hours to study the material is not enough. The material is interesting for students and allows using the method of project activity. Students received brief information on the topic of the project, individual and group tasks. As a result, they were able to show independence in acquiring knowledge on this topic, show their creative activity, show imagination in the selection and design of additional material. The work on the project gave students the opportunity to actively use the acquired skills in practice. They learned to determine the coordinates various objects using a coordinate system. Children performed drawings on the coordinate plane with interest. This topic is a preparatory stage for plotting functions.

Subjects related to Coordinate Plane

Mathematics (Coordinate plane); geography (Geographic coordinates; Determining the location on the map,); Astronomy (stellar coordinates); Chemistry - building the periodic table (the position of each element in the table is also determined by the coordinates: row and column)

Questions guiding the project

Fundamental question:

How does "dry" mathematics allow us to navigate in the environment around us?

Problematic issues

Is the coordinate system purely mathematical concept?

Study questions

What is a coordinate plane?
What is a coordinate system?
At what angle do the coordinate lines X and Y intersect, forming a coordinate system on the plane?
What is the name of each of these lines?
What is the point of intersection of these lines called?
What is the name of a pair of numbers that determine the position of a point on a plane?
What is the name of the first number? Second number?
How to find the abscissa and ordinate?
How to plot a point by its coordinates?

Who first introduced the coordinate plane?

Where is the coordinate system used?

Methodical tasks:

Introduce the concept of a coordinate system on a plane, the concept of a coordinate plane, coordinate axes

Teach how to build a point on a plane according to its coordinates and find the coordinates of points

Learn to draw by coordinates and determine the coordinates of the points of the picture.

Learn how to express your thoughts orally and in writing

Project plan

Organizational and preparatory stage

Teacher's introductory talk:
What do you need to know to find the person you need?
How to find your place in the class? In the theatre?
Do you know how to find the treasure?
How can you help a sinking ship?
How to find the star you are interested in in the sky?

Practical stage.

Tasks for groups of students wishing to take part in the project:

1: Find and study information about the history of the origin of the coordinate plane, prepare a message on the topic.

2: Prepare theoretical information about the coordinate system. Check the assimilation of the material in the form of a test.

3: Learn how the periodic table is related to the coordinate plane.

a) Construct an image of the constellations Ursa Minor and Ursa Major in coordinates.

b) Organize a competition "Draw by coordinates".

c) Construct a graph of temperature changes during the day on April 26 (Each student received the task to record the temperature at a certain time of the day).

Why and where people need coordinates

AT Everyday life in the speech of adults, we sometimes hear the following phrase: “Leave me your coordinates.” This expression means that the interlocutor must leave his address or phone number, which in this case is considered the coordinates of the person. The main thing here is that according to these data you can find a person. This is precisely the essence of coordinates or, as they usually say, coordinate systems: this is the rule by which the position of an object is determined.

Coordinate systems permeate the entire practical life of a person. In addition to postal addresses and phone numbers, we are already familiar with the coordinate system in the cinema auditorium (row number and seat number), in the train (car number and seat number), with the geographic coordinate system (longitude and latitude). If it wasn't geographical system coordinates, it would be impossible to help the sinking ship. When studying astronomy, a coordinate system is also used to determine the location of stars. In chemistry lessons, studying the periodic table, we will also meet with a coordinate system. Those of you who have played "sea battle" used the appropriate coordinate system. Each cell on the playing field is determined by a letter and a number. The letters mark the horizontals of the playing field, and the numbers mark the verticals. A similar coordinate system is used in chess. This kind of "cellular coordinates" are commonly used on military, nautical, geological maps. So knowledge of the coordinate system is necessary not only in mathematics lessons.

Question 1. What is the equator?

The equator is a section of the earth's surface by a plane passing through the center of the earth, perpendicular to the axis of its rotation. Its length is approximately equal to 40075 km.

Question 2. What hemispheres does the equator divide the Earth into?

The equator divides the globe into northern and southern hemispheres.

Question 3. What planets are included solar system?

The solar system includes the following planets: ☿ Mercury, ♀ Venus, ⊕ Earth, ♂ Mars, ♃ Jupiter, ♄ Saturn, ♅ Uranus, ♆ Neptune.

Question 4. Is it possible to determine the coordinates on the plane and on the surface of the ball in the same way?

Yes, you can, for this you need to know the latitude and longitude.

Question 5. What are the coordinates for?

To determine the location of a point on a map or globe, you need to know two coordinates.

Question 6. What hemispheres does the equator divide the globe into?

The equator divides the globe into northern and southern hemispheres.

Question 7. What is a parallel?

Lines that are parallel to the equator and have different latitudes are called parallels. On geographical maps, parallels are depicted as straight lines or arcs of circles of different curvature, and on the globe - as circles of different diameters. The closer to the pole, the smaller the diameter of the circle.

Question 8. What is a meridian?

The line connecting both poles on the surface of the Earth in the shortest possible way is called the meridian.

Question 9. Why is the prime meridian called Greenwich? Zero?

Because the meridian that passes through the old astronomical observatory, which was located in England in the town of Greenwich, began to be called the initial, zero or Greenwich.

Question 10. What hemispheres divide the globe zero and 180 meridians?

If we move from the Greenwich meridian east to the 180° meridian, then we will be in the Eastern Hemisphere. If, on the contrary, to the west of the Greenwich meridian, then until the 180th meridian we will be in the Western Hemisphere.

Question 11. What does the geographic latitude show?

The geographical latitude of a point is the distance, expressed in degrees, from the equator to that point. Latitude is north and south. Geographic latitude changes from 0 to 90°. The parallel defines the west-east direction.

Question 12. What is geographic longitude?

The geographical longitude of a point is the distance, expressed in degrees, from the prime meridian to that point. Longitude is east and west.

Question 13. In what intervals do the values of geographic latitude and geographic longitude change?

Geographic latitude varies from 0 to 90°. Geographic longitude varies from 0° to 180°.

Question 14. How is the equator different from any other parallel?

The equator is a reference line for geographic latitude, so its own geographic latitude is 0 latitude. The equator runs in the center and is the largest parallel in diameter and radius.

Question 15. What are the geographic coordinates of the Earth's poles? Explain the difference between these coordinates and the coordinates of any other point on the Earth's surface.

The poles have a maximum latitude of 90°. North Pole - 90° N sh., Yuzhny - 90 ° S sh. The difference from other coordinates is that the poles do not have longitude values.

Question 16. Why is the shape of the parallels and meridians different on the map and the globe?

The form of parallels and meridians differs on the map and the globe, because the globe has the shape of a ball - just like the Earth itself, and the map is an image of the Earth on a plane, so there are distortions.

Question 17. Using the maps of the atlas, determine the geographical coordinates of Moscow, Paris and Sydney. What unites geographical coordinates: Moscow and Paris; Moscow and Sydney

Moscow: 55°N sh. 37° E Paris: 48°N sh. 2° in. Sydney: 33°S sh. 151° E e. The coordinates of Paris and Moscow are united by the fact that these cities are located in the Northern and Western hemispheres, and Moscow and Sydney by the fact that they are located in the Western Hemisphere.

Question 18. Determine the geographical coordinates of the point of intersection of the equator and the prime meridian.

The geographical latitude of the equator is 0°. Geographic longitude of the initial - 0 °. Therefore, the coordinates of the intersection point 0 ° w. 0° in.