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» What is a nautical mile and what is a knot equal to?

What is a nautical mile and what is a knot equal to?

In order to find out how many meters there are in a nautical mile, you need to use a simple online calculator. Enter in the left field the number of nautical miles you want to convert. In the field on the right you will see the result of the calculation. If you need to convert nautical miles or meters to other units of measurement, simply click on the appropriate link.

The nautical mile is a non-systemic unit of measurement; its use is not recommended, but is allowed. Distances at sea are measured in nautical miles. One nautical mile is 1,852 meters, respectively, one kilometer is 0.5399568 nautical miles. This value was introduced in 1929 at the international hydrographic conference in Monaco without designation, in practice nautical mile abbreviated as M, NM, Nm, nmi.

Since the time of Mercator, the length of a nautical mile has been considered to be 1 minute of degree of meridian arc (1/21600 of the length of the meridian arc). Since the earth's surface is spherical, the value of 1 minute of degree of meridian is different at the poles (1,861.6 m) and at the equator (1,842.9 m). The unified value is equal to the length of a minute of a meridian degree at latitude 45º (1,852.2 m). This unit of measurement is convenient for navigation, since it is both an angular and linear measure. Before 1955, the US nautical mile was 1,853.248 meters or 6,080.20 feet.

What is "meter"

Meter (m, m) is one of the seven basic units of the International System (SI), also included in the ISS, ICSA, ICSC, ICSG, MSK, ICSL, ISS, ICSS and MTS. A meter is the distance that light travels in a vacuum in 1/299,792,458 of a second. From the definition adopted in 1983 by the General Conference on Weights and Measures, it follows that the concept of “meter” is tied to the second by means of a universal constant (the speed of light).

In Europe, for a long time there were no standard measures for determining length. An urgent need for unification arose in the 17th century. With the development of science, a search began for a measure based on a natural phenomenon and allowing calculations in the decimal system. Then the “Catholic meter” of the Italian scientist Tito Livio Burattini was adopted.

In 1960, the man-made standard was abandoned and until 1983 the meter was the number 1,650,763.73 multiplied by the wavelength of the orange line (6,056 Å) of the spectrum emitted by the krypton isotope 86Kr in a vacuum. This prototype is now out of use. Since the mid-70s of the last century, when the most accurate determination of the speed of light became possible, the existing concept of a meter, tied to the speed of light in vacuum conditions, was adopted.

Nautical mile- a unit of distance used for navigation and aviation.

Since the Earth is actually a spherical shape, but a geoid (oblate at the poles), the one-minute meridian corresponds to approximately 1862 m and 1843 m to the equator (average about 1852 m).

According to the modern definition adopted in the 1929 International Monograph on Hydrophotography, international nautical mile exactly 1852 meters.

The nautical mile is not an SI unit, but its use is permitted as defined by the General Conference on Weights and Measures, although it is not recommended.

There is no generally accepted name; Sometimes the abbreviations "NM", "nm" or "nmi" (from English) are used. nautical mile). It should be noted that the abbreviation “nm” coincides with the officially accepted nanometer mark.

UK nautical miles before the transition to the international system (before 1970) = 1853,184 meters.

This is because we wanted to simplify the conversion from English miles to sea. One mile (5,280 feet) was added by 800 feet, and the English nautical mile (Admiralty mile) was 6,080 feet.

United States nautical miles before moving to the international system (pre-1955) = 1853,248 meters or 6080.20 meters.

See also

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links

  • Bureau of International Research and Relations (BIPM): 8th edition.

    ISBN 92-822-2213-6.

  • International Bureau for the Control of Riots and Mesurures: International organization Le Système (SI), 6e edition, 199, ISBN 92-822-2112-1
  • A. Sacklowski: Einheitenlexikon, Entstehung, Anwendung, Erläuterung von Gesetz und Normen, Berlin: Beuth-Verlag, 1986 (Beuth-Kommentare) ISBN 3-410-11988-4

Passage marking the nautical mile

As several Austrian soldiers passed, Rostov noticed that the next part of the line (which was the guard) was already in action.
"So much better!"

I’ll look around, he thought.
He was driving almost along the front. Some riders rallied against him. These were our Ulans, who returned from the attack in disorganized ranks.

Rostov wore them, he involuntarily noticed one of them in his blood and bent down again.
"I don't care!" - he thought.

Before he could ride a few hundred steps after that, on the left side to intercept him, a huge mass of cavalry on a black horse appeared in the entire playing field, with a white shining uniform standing in front of him. Rostov put his horse into a full gallop to get out of the way of these cavalrymen, and he would have left them if they were walking anyway, but everyone added speed, so some horses jumped.

Rostov became more and more audible, and their bells and weapons became their sounds, and their horses, figures and even faces became more noticeable. It was our horsemen who attacked the French cavalry, which opposed them.
The riders have galloped, but they still have horses. Rostov already saw his cheeks and heard the order: “March, march!” The officer who pulled the bloody horse into in full swing, said it.

Rostov, who was afraid of being crushed or entangled in an attack on the French, he moved along the front, which was the urine of his horse and had not yet crossed.
Rok Strazhar, a huge increase in the pockmarked man, angrily angered Rostov in front of him, which he urgently had to face. This guardsman almost hit Rostov with his Bedouin (Rostov, which I felt so small and weak compared to these big men and horses), if you did not think of swinging your whip in the eyes of his cavalry horse.

Crows, a heavy five-inch horse, are always right when giving ears; but the pockmarked Guardsman dragged her hips to swing his large paws and horses, waving his tail and speeding up his neck even more. As soon as the horse guards passed by Rostov, he heard them shout: “Hura!” And when I looked back, he saw that their first rank was mixed with other people, probably French cavalry with red elephants. There was nothing to be seen, as it was immediately after the gun was fired, and everyone was dressed in smoke.

Nautical mile- a unit of distance used for navigation and aviation.

The nautical mile was originally defined as the length of a great circle on the surface of the world, which measures one minute of arc. This movement to one nautical mile along the meridian approximately corresponds to a change geographical coordinates per minute of latitude.

Since the Earth is not actually spherical, but rather a geoid (flattened by the poles), one meridian minute corresponds to approximately 1842 m at the pole and 1843 m at the equator (an average of about 1852 m). According to the modern definition adopted in the 1929 International Monograph on Hydrophotography, international nautical mile(International nautical mile) exactly 1852 meters.

The nautical mile is not an SI unit, but its use is permitted as defined by the General Conference on Weights and Measures, although it is not recommended. There is no generally accepted name; the abbreviations "NM", "nm" or "nmi" (from English nautical mile) are sometimes used. It should be noted that the abbreviation “nm” coincides with the officially accepted nanometer mark.

International nautical mile = 10 cables = 1/3 nautical leagues

UK nautical miles before the transition to the international system (until 1970) were 6,080 feet = 1,853,184 meters.

This is because we wanted to simplify the conversion from English miles to sea. One mile (5,280 ft) was added 800 ft, while the English nautical mile (Admiralty mile) was 6,080 ft [ source not specified for 313 days]

United States nautical miles before moving to the international system (pre-1955) = 1853,248 meters or 6080.20 meters.

See also

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In order to find out how many nautical miles are in a kilometer, you need to use a simple online calculator. Enter in the left field the number of kilometers you are interested in that you want to convert. In the field on the right you will see the result of the calculation. If you need to convert kilometers or nautical miles to other units of measurement, simply click on the appropriate link.

What is a "kilometer"

Kilometer (km, km) is a multiple of the meter standard unit for measuring distance, widely used throughout the world.

One kilometer is 1,000 meters, 0.621 miles, 0.9374 versts, 1,094 yards, 3,281 feet, 1.057 x 10 − 13 light years, 6.67 x 10 − 9 astronomical units.

What is a "nautical mile"

The nautical mile is a non-systemic unit of measurement; its use is not recommended, but is allowed.

Distances at sea are measured in nautical miles. One nautical mile is 1,852 meters, respectively, one kilometer is 0.5399568 nautical miles.

This value was introduced in 1929 at the international hydrographic conference in Monaco without a designation; in practice, the nautical mile is abbreviated as M, NM, Nm, nmi.

Since the time of Mercator, the length of a nautical mile has been considered to be 1 minute of degree of meridian arc (1/21600 of the length of the meridian arc).

Since the earth's surface is spherical, the value of 1 minute of degree of meridian is different at the poles (1,861.6 m) and at the equator (1,842.9 m).

The unified value is equal to the length of a minute of a meridian degree at latitude 45º (1,852.2 m). This unit of measurement is convenient for navigation, since it is both an angular and linear measure. Before 1955, the US nautical mile was 1,853.248 meters or 6,080.20 feet.

Every schoolchild knows perfectly well that a nautical mile is a unit of measurement that calculates distance over large expanses of water. Nowadays this value is not included in the international system physical units, however, it is widely used by almost all peoples, both European and American. That is why in different sources you can find different designations for this indicator. Among these are NM, nmi and others.

The history of the nautical mile

The nautical mile appeared around the Renaissance. Then the sailors calculated the distances that they had to sail on ships, based on the characteristics of the arcs of the earth's meridians. So this naval unit of distance measurement was equal to the length of one degree of the meridian arc, and was calculated using a complex mathematical formula. However, due to the fact that our planet had and still has the shape of an ellipse, this arc minute in practice was not a constant value. Since the radius of curvature in certain latitudes of the ellipsoid is different, such a value as a nautical mile would be smallest near the equator and largest at the Earth’s poles.

Final adoption of this metric unit

In this regard, in the twentieth century, in particular in the USSR, the average standard unit of measurement of distance in the sea was adopted. The formula by which this value was calculated was based on an angle of 45 degrees, and the result was a number equal to 1852 meters. Despite the fact that the nautical mile can be converted into units of measurement so familiar to us, it is not used as a metric measure. Since it is based on one degree of arc of the meridian of our planet, it becomes an angular unit of measurement. In matters related to shipping, especially on fairly long distances, it is very convenient and acceptable.

Mathematical division of one mile

As we can see, a nautical mile in total is almost two kilometers. In some cases, this value is too large for sea travel. That is why this value was divided into cables. There are 10 cables in one mile, which in turn is equal to one-third of a naval league. This value is not used in shipping and other sciences, but sometimes it serves as a guideline that allows us to make more accurate calculations, lay out a more detailed and correct sea route.

What other miles are there?

Knowing the features of American units of measurement, many people are confused about what 1 nautical mile is equal to. In this country, this measure is used not only in shipping, but also overland distances. One US mile, which is often used to indicate the speed of a car and the distance it travels, is equal to 1609.344 meters. It is also worth noting that in this country, in some cases, there are differences in maritime units of measurement of lengths. Thus, a nautical mile in the states in some documents is equal to 1853.249 meters. However, if it is necessary to export cargo according to documents concluded with the countries of Europe and Asia, then it is applied international system measurements, which was recognized as official in 1929.

Or adventures, in films about desperate sailors, in articles on geographical topic and the term “nautical mile” often slips into conversation between sailors. The time has come to figure out what length is equal to in shipping, and why sailors do not use the kilometers we are accustomed to.

What is 1 nautical mile?

Initially, this value corresponded to the length of 1/60 degree of the arc of a circle on the surface of the Earth with the center coinciding with the center of the planet. In other words, if we consider any meridian, then a nautical mile will be approximately equal to the length of one minute of latitude. Since it differs somewhat from the outline of an ideal sphere, the length of 1 minute of a degree of the meridian in question may differ slightly depending on latitude. This distance is greatest at the poles - 1861.6 m, and least at the equator - 1842.9 m. To avoid confusion, it was proposed to unify the length of the nautical mile. The length taken as a basis was 1 minute of degree at 45º latitude (1852.2 m). This definition led to the fact that the nautical mile became convenient for calculating navigation problems. For example, if you need to measure a distance of 20 miles on a map, then it will be enough to measure 20 arc minutes with a compass on any meridian marked on the map.

Beginning in 1954, the United States began using the international nautical mile (1852 m). In practice, it is often rounded to 1800 meters. An official designation for this unit was never adopted. Sometimes the abbreviation "nmi", "nm" or "NM" is used. By the way, “nm” is the generally accepted designation for nanometer. 1/10 international nautical mile = 1 cable = 185.2 meters. And 3 miles are equal to 1 nautical league. In the past, the UK often used its own nautical mile, equal to 1853.184 m. In 1929, an international conference was held in Monaco on various issues of hydrography, at which the length of the nautical mile was determined to be 1852.00 meters. Do not forget that a mile can be not only sea, but also land. In this case, its length is 1.151 times less than sea length.

What is the relationship between a nautical mile and a knot?

The nautical mile, or, as it is sometimes called, geographical or navigational, has become widespread in geography, aviation and navigation. Closely related to it is the concept of a sea knot, used in shipping as the basic unit of speed. One knot is equal to one mile traveled per hour of the ship's movement. The name “knot” is due to the fact that in the old days a log was used on ships to measure speed. It was a log or board in the shape of a triangle to which a load was tied. A line (rope) was attached to this, on which knots were tied at a certain distance. The log was thrown overboard, after which, over a selected period of time (from 15 seconds to 1 minute), the number of knots that went into the water was counted.

Eat different versions relative to the distance between nodes. Some believe that it was 25 feet and if one knot left in 15 seconds, the result was one nautical mile (100 feet/min). According to the second version, the knots were tied in 47 feet and 3 inches (14.4018 m), and the countdown took 28 seconds. In this case, one knot showed a speed of 101.25 ft/min.

We hope that now you will not have difficulty understanding maritime terminology, and miles with knots will become as understandable as regular kilometers.

MILE SEA

MILE SEA

(Nautical mile) - the length of 1\" of the meridian arc, considering the Earth to be a ball whose volume is equal to the volume of the earth's ellipsoid. Then the value of the nautical mile is determined from the equality:

n= 2π R/360·60 = R·arc 1\",

and according to the specified condition, where - semimajor axis of the earth's spheroid, b- minor axis.

If we take the values ​​of these semi-axes according to the Clarke spheroid data, then n comes out to be 1853.3 m = 6080.4 ft. But in the USSR, all maps are built on the basis of Bessel spheroid data, therefore, by circular of the Hydrographic Administration No. 317 dated 8/VII 1931, the value of the nautical mile was set at 1852.0 m, which corresponds to the length of 1\" arc of the elliptical meridian at latitude 45°, i.e. the value:

(a + b)/2 arc1\"

according to Bessel spheroid data.

If we take 1" arc of the elliptical meridian as a unit for measuring distances, then the divisions of the vertical frames of the map will represent this scale. This value changes with the latitude of the place from 1842.7 m= 6045.7 feet at equator to 1861.3 m= 6106.7 feet at the poles. Difference 18.6 m, component of 1% lies outside the accuracy of measuring lag distances.

Our standard nautical mile is 1852.0 m = 6076.1 feet is used to calibrate the log scale and for various calculations.

The British consider a nautical mile to be equal to 6080 feet. and call it "Admiralty knot".

They call the length of 1" of the earth's elliptical meridian, i.e., a value that varies with latitude, "Nautical mile" or "Sea mile".

In other countries where other values ​​are adopted for the semi-axes of the ellipsoid And b or where is the radius of the imaginary globe, replacing the earth's ellipsoid, is determined not from a comparison of volumes, but by other methods, for example. By comparing the surfaces, there and for the nautical mile we obtain values ​​that are slightly different from 6080 feet, but close to them. The table below shows the nautical mile lengths adopted in various countries.

States

Nautical mile length

Germany

Holland

Portugal

Samoilov K. I. Marine dictionary. - M.-L.: State Naval Publishing House of the NKVMF of the USSR, 1941

nautical mile

unit for measuring distances at sea, equal to length arc of the earth's meridian in 1'. In different countries, the mile is defined at different latitudes, so it has different meanings. In Russia, a nautical mile is taken at latitude 44°30’ and is 1852 m, in the UK and Japan - 1853.18 m, in the USA - 1853.24 m, in Italy - 1851.85 m. The international nautical mile is 1852 m.

EdwART. Explanatory Naval Dictionary, 2010

Mile Morskaya

naval unit of length used for measurements at sea, equal to 1852 m. The old Russian mile was equal to 7.468 m.

EdwART. Marine Dictionary, 2010


See what "SEA MILE" is in other dictionaries:

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    1 nautical mile is equal to 1852 m Dictionary of business terms. Akademik.ru. 2001... Dictionary of business terms

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