The concept of geodetic and astronomical azimuths. Origin of the word azimuth. G. Larionov, E.A. Orel Experience in analyzing social networks of organizations using the Azimuth technique
Azimuth - the angle measured on the horizontal plane between the vertical planes of the meridian and the sighting strip; the angle between the direction towards a point and the direction towards some other point or object. Yes - magnetic, geographic azimuth. Azimuth is measured from 0 to 360 degrees.
Azimuths are called real, geographic or astronomical, in which case they are counted from the direction geographical meridian; they are measured from a meridian determined from astronomical observations.
Magnetic azimuths are measured from the direction of the magnetic meridian, indicated by the direction of the magnetic arrow. Azimuth is called conventional when a conventional meridian is taken for calculation. The directions of the true meridian and the magnetic one at the given point do not coincide, and therefore the real and magnetic azimuth differ from each other by a certain angle - the declination angle.
Knowing the declination angle for a given point and in a given era, it is possible to find the present and back magnetic azimuth with a certain accuracy. All meridians converge at one point - at the pole; the angle between 2 meridians is called the angle of convergence of the meridians; in this case, if a straight line intersects a few meridians, then at the intersection points azimuths will be created that differ from each other by the angle of approach of the meridians; the angle of approach of the meridians of two points of the same straight strip depends on the length of the strip, its direction and the latitude of the place. The azimuth measured at the starting point of the strip is called direct; The azimuth measured from the end point to the source point is called the reverse azimuth. The reverse azimuth (a2) is equal to the forward azimuth (a1) plus or minus 180° and plus the angle of approach of the meridians t, i.e. a2 - a1± 180° +t.
In mid-latitudes, for a strip of 15 km, the angle of approach is approximately 10"; in almost all cases of daily practice, they treat this angle of approach of meridians and consider that the forward and reverse azimuths differ by exactly 180°, or a2 = a1± 180°. This accepted in lower geodesy for small areas of the earth's surface, however, for huge distances and measurements with greater accuracy, calculations are performed according to the rules of higher geodesy, taking into account the convergence of meridians and spherical excess(cm.). In such cases, the formula a2 = a1± 180° + t-e is used, where t is the angle of approach, calculated using special formulas, and e-kurtosis, or excess, over 180° of the sum of the angles of a spherical triangle on earth's surface, also determined by a special formula.
Azimuth in astronomy:
Azimuth The luminary is called the arc of the mathematical horizon from the point of south to the vertical circle of the luminary, or the angle between the noon line and the line of intersection of the plane of the mathematical horizon with the plane of the vertical circle of the luminary.
Azimuths are measured in the direction of the daily rotation of the celestial sphere, in other words, to the west of the south point, within the boundaries from 0° to 360°. From time to time, azimuths are measured from 0° to +180° west and from 0° to -180° east. (In geodesy, azimuths are measured from the north point.)
Azimuth in geodesy:
Azimuth- the angle between the direction to the north and the direction to some distant object. It is usually counted clockwise.
When determining azimuth using a compass, you need to introduce a correction for the so-called. magnetic declination arising as a result of the discrepancy between geographical and magnetic poles land.
direction azimuth in degreesnorth0° or 360°northeast45°east90°southeast135°south180°southwest225°west270°northwest315°
Primary sources:
Wikipedia - azimuth in astronomy;
Wikipedia - azimuth in geodesy;
Azimuth | Techno encyclopedia. - Techno encyclopedia
Calculation of a constant azimuth and the length of the rumba strip between 2 points for geodetic coordinates(GIS-lab)
Calculation of the distance and initial azimuth between 2 points on the sphere (GIS-lab)
Data preparation and movement along azimuths - Determination of azimuth by compass. Determination of magnetic azimuths. Movement in azimuths
Real azimuth and magnetic azimuth - orientation on a hiking trip.
Azimuths and movement along azimuths (Adelbaev Vadim)
(from the Arabic word assum û t, i.e. path, road) - is the angle formed by the meridian plane with vertical plane, passing through this luminary, and measured by the arc of the horizon, which is contained between these two planes. The azimuth is eastern and western, depending on whether the given star is located east or west of the meridian, and is equal to zero when it is on the meridian (southern) or at its highest, culminating point. In astronomy, the azimuth of a star is generally considered to be from 0° to 360°, so that the distinction between eastern and western azimuth becomes unnecessary.
- - the angle between the direction of the terrain line and the meridian passing through a given point. The value of A. is counted from the north. the end of the meridian - clockwise along this line and can vary from 0° to 360°...
Agricultural dictionary-reference book
- - manual , lp Koltukana Prav. In Selemdzhinsky...
Toponymic Dictionary of the Amur Region
- - the angle between the plane of the meridian of the observation point and the vertical plane passing through this point and the observed luminary, object, etc. Counted from point Yu to ...
Astronomical Dictionary
- - direction: ஐ "First - to LT-8, prepare lasers, target - cloud, low power, to the billierg at the epicenter, continuous fire in azimuth!" -...
Lem's World - Dictionary and Guide
- - celestial body, the dihedral angle between the meridian plane of the observation point and the vertical plane passing through this point and the observed object. Depending on the type of meridian from which it is produced...
Glossary of military terms
- - M. Astronomer. close the arc, see, between the midday and the plumb line. Azimuthal, azimuth, related to azimuth. Azimuthal sundial, lying, lying on the level, not wall...
Modern encyclopedia
- - azimuth is the angle between the meridian plane of the observation point and the vertical plane passing through this point and the observed object...
- - object, direction, angle between the meridian plane of the observation point and the vertical. plane passing through this point and the observed object. Counted from N. or S. clockwise from 0 to 360°...
Natural science. encyclopedic Dictionary
- - the horizontal angle between the meridian plane of the observation point and the vertical plane passing through this point and the observed object - azimuth - azimut - Azimut - azimut - zovkhis chig - azymut - azimut - azimut - acimut - azimuth -...
- - - dihedral angle between the meridian plane of the observation point and the vertical plane passing in a given direction, measured from the direction C. clockwise...
Geological encyclopedia
- - a celestial body, an earthly object, etc. - a dihedral angle between the meridian plane of the observation point and the vertical. a plane passing through this point and the observed luminary, object, etc...
Big Encyclopedic Polytechnic Dictionary
- - luminary - spherical angle at zenith between the vertical of the luminary and the meridian of the observer...
Marine dictionary
- - a luminary is the angle formed by the plane of the meridian with the vertical plane passing through this luminary, and measured by the arc of the horizon, which is contained between these two planes...
- - is the angle formed by the plane of the meridian with the vertical plane passing through this luminary, and measured by the arc of the horizon, which is contained between these two planes...
Encyclopedic Dictionary of Brockhaus and Euphron
- - object, direction, angle between the meridian plane of the observation point and the vertical plane passing through this point and the observed object. Counted from north or south clockwise from 0 to 360....
- - ...
Spelling dictionary of the Russian language
"Azimuth of the Sun" in books
Azimuth – know!
author Loza Dmitry FedorovichAzimuth – know! In January 1945 there were fierce round-the-clock battles with an encircled enemy group in the Hungarian capital. The enemy made three desperate attempts to release his troops trapped in the “cauldron.” On January 2 they were inflicted
His Majesty Azimuth
From the book Tanker in a Foreign Car. Defeated Germany, defeated Japan author Loza Dmitry FedorovichTHE SUN AND THE LIGHTS
From the book Life Itself authorTHE SUN AND THE LIGHTS A Quarter of a Century We met Father Alexander in the summer of 1965 (I don’t remember the month). Mikhail Agursky, then called Melik, brought me to him. I lived in Lithuania, I had just arrived in Moscow, and those whom I did not have time to visit were mostly middle-aged
Sun and luminaries
From the book Life Itself author Trauberg Natalya LeonidovnaSun and luminaries One more thing: there is no such thing as hope, There is something more than hope. Thomas Venclova
Azimuth - know!
author Loza Dmitry FedorovichAzimuth - know! In January 1945 there were fierce round-the-clock battles with an encircled enemy group in the Hungarian capital. The enemy made three desperate attempts to release his troops trapped in the “cauldron.” On January 2 they were inflicted
His Majesty Azimuth
From the book Tanker in a Foreign Car. They defeated Germany and defeated Japan. author Loza Dmitry FedorovichHis Majesty Azimuth Brigade units are ready for battle. The Shermans are fully equipped with crews that have been fired upon in the west. However, the little experience of moving in azimuth with the help of a gyrocompass, which we acquired in the west, was not enough for reliable
Chapter Four Azimuth - to the West
From the book The Wind of the War Years author Baklanov Gleb VladimirovichChapter Four Azimuth - to the West The crossing was calm: on the right bank of the Dnieper there were formations of the 7th Guards Army of General Shumilov and the 5th Guards tank army General Rotmistrov had already held a bridgehead for several days, stretching along the river for kilometers
Luminaries
From the book The Magic of the Name. Cosmic discovery codes author Estrin AnatolyLuminaries of the Sun The central place in our planetary system is occupied by the Sun. It is this that gives life to all planets, shows them the path - the trajectory of movement in orbits, establishes and regulates the cosmic and biological rhythms of the existence of all forms of life. The Sun
Luminaries
by Baggott JimLuminaries
From the book The Secret History atomic bomb by Baggott JimLuminaries In the spring of 1942, the S-1 program was gaining momentum, and Teller could only wait for the weather by the sea. Szilard, extremely outraged by Compton's undemocratic decision to concentrate research in Chicago, nevertheless packed his bags and moved there at the end of January 1942
Azimuth
From the book Big Soviet Encyclopedia(AZ) author TSBLaplace azimuth
From the book Great Soviet Encyclopedia (LA) by the author TSBA.G. Larionov, E.A. Orel Experience in analyzing social networks of organizations using the Azimuth technique
From book Psychological problems modern business: collection of scientific articles author Ivanova Natalya LvovnaA.G. Larionov, E.A. Eagle Experience Analysis social networks organizations using the Azimuth methodology As competition grows in global markets, rapid development computer technology and, as a consequence, the need to ensure investment attractiveness in
The birth of a luminary
From the book Psychology day by day. Events and lessons author Stepanov Sergey SergeevichThe birth of a luminary Every year at the beginning of May, the psychoanalytic community more or less magnificently (depending on the roundness of the date) celebrates the birthday of the one who for many years provided this community with the meaning of existence and a piece of rich bread. May 6th – birthday
True azimuth and magnetic azimuth
From the book ABC of Tourism author Bardin Kirill VasilievichTrue azimuth and magnetic azimuth To complete the consideration of issues related to orientation, it is necessary to consider one more issue. In the previous presentation, we assumed that the direction north shown on the map and the direction north determined
Horizontal coordinate system. The main planes from which coordinates are measured in this system are the observer's meridian and the plane of the true horizon. The horizontal coordinate system includes the height of the luminary h and azimuth A.
The height of the luminary h is the angle (KOo) between the plane of the true horizon and the direction from the center of the celestial sphere to the center of the luminary (Fig. 73). The height of the luminary is measured by a vertical arc from the true horizon to the center of the luminary (Ko) in the range from O to 90°. Altitude is assigned a plus sign if the luminary is above the horizon, and a minus sign if it is located below the horizon. In the latter case, the height is called decline.
Rice. 73.
Instead of height, sometimes they use the zenith distance z, which is the addition of the height to 90°, i.e. z = 90°-h; it is measured by a vertical arc from the zenith to the center of the luminary in the range from 0 to 180°.
To determine the location of the luminary, it is also necessary to determine the position of the vertical passing through it. The vertical position determines the azimuth.
Azimuth- this is the spherical angle at zenith, enclosed between the meridian of the observer and the vertical of the luminary; measured by the arc of the true horizon from one of the observer's meridian points. The observer's meridian point is chosen in accordance with practical necessity and convenience in calculations. In nautical astronomy, three systems for calculating azimuth are accepted: circular, semicircular and quarter.
In a circular calculation, the azimuth is measured by the arc of the true horizon from point N towards O st to the vertical of the luminary in the range from O to 360° and is written as follows: A = 120° (arc NO st K, Fig. 73).
With semicircular counting, azimuth is measured by the arc of the true horizon from the midnight part of the observer's meridian towards the east or west to the vertical of the luminary in the range from 0 to 180°.
The semicircular azimuth is written: A = N120°O st (arc NO st K). The first letter is always the same as the latitude, since the name of the midnight part of the observer's meridian is determined by the name of the elevated pole. The second letter is determined by the location of the star in the eastern or western hemisphere.
Rice. 74.
When counting quarterly, the azimuth is measured by the arc of the true horizon from the north point N or from the south point S towards the east or west to the vertical of the luminary in the range from 0 to 90° and write A = 60°SO (arc SK).
Due to the rotation of the Earth, the altitude and azimuth of the star are constantly changing.
On a ship, the height of the luminary is measured with a sextant, and the azimuth can be approximately determined using a compass or calculated using the formulas of spherical trigonometry.
Equatorial coordinate system. There are two systems of equatorial coordinates. The main planes in the first equatorial system are the observer's meridian and the plane of the celestial equator. The coordinates in this system will be hour angle t and declination 6.
Hour angle called the spherical angle at an elevated pole, enclosed between the noon part of the observer’s meridian and the circle of declination of the star (QPNK, Fig. 74). Two systems for counting hour angles have been adopted.
The ordinary hour angle is measured by the arc of the celestial equator from the midday part of the observer's meridian towards the west to the circle of declination of the star in the range from 0 to 360°. In Fig. 74 arc QWQ" O st K and t~310°.
The practical hour angle is measured by the arc of the celestial equator from the midday part of the observer's meridian towards the west or east to the circle of declination of the star in the range from 0 to 180° (arc QK). The practical hour angle is always given the name Ost or W, for example t~50°O st.
Declination of the luminary b they call the angle between the plane of the celestial equator and the direction from the center of the celestial sphere to the center of the body KOo.
Declination is measured by the arc of the declination circle from the celestial equator to the center of the star, ranging from 0 to 90°. The declination is assigned the letter N if the luminary is in the northern hemisphere, and S if it is in the southern hemisphere: for example, b = 40°N (see Fig. 74).
When calculating, the declination is assigned a “plus” sign if it is the same as the latitude, and a “minus” sign if it is different. Instead of declension, they are sometimes considered polar distance A, which is the complement of declination to 90°, i.e. A = 90°-b. The polar distance is measured by the arc of the declination circle from the elevated pole to the center of the star in the range from 0 to 180°.
As the Earth rotates, the declination remains unchanged throughout the day, but the hour angle changes.
The second coordinate system includes right ascension a and declination b (or polar distance A).
On the celestial equator there is a conditional fixed point called the Aries T point. Right ascension a is measured by the arc of the celestial equator from the Aries T point to the circle of declination of the star in the direction opposite to the calculation of ordinary hour angles, ranging from 0 to 360 °.
The concepts of declination and polar distance are the same as in the first equatorial coordinate system. The rotation of the Earth does not cause changes in the values of right ascension and declination, therefore these coordinates are used to compile star maps and star catalogs (Appendix 6).
Astronomical azimuth directions MK called the angle between the north direction of the astronomical meridian of the observation point M and observed direction MK.
Astronomical latitudes, longitudes and azimuths on the earth's surface can be determined from observations of stars.
Geodetic azimuth A directions MK(Fig. 2.1) (on the earth's surface) or mk(on an ellipsoid) is the angle between the north direction of the geodetic meridian PmP" observation points and direction MK, reduced to the surface of the ellipsoid. Geodetic azimuth is counted clockwise from the northern direction of the meridian, from 0 0 to 360 0.
Geodetic azimuth can be obtained in two ways:
1) by transmitting azimuths along the sides of the geodetic network, using the original azimuth at its starting point, obtained by orienting the reference ellipsoid, and the angles of the network;
2) by determining the astronomical azimuth and then obtaining the geodetic azimuth of the direction MK according to the formula
where is the geodetic and is the astronomical longitude of the point M; - astronomical latitude of the point M; and - reduction corrections in direction MK for transferring it from the earth's surface to the surface of the reference ellipsoid, and - a correction for the deviation of the plumb line from the normal to the ellipsoid at the point M, a is the correction for the height of the sighting target at the point K above the surface of the ellipsoid. Formulas for calculating these small corrections, taken into account during high-precision measurements, will be given in the lecture devoted to the mathematical processing of the results of angular observations.
The geodetic azimuth obtained using formula (2.1) is called Laplace azimuth. The geodetic point at which the astronomical azimuth and longitude were determined is called Laplace point, and the correction term 
-Laplace's correction.
| K |
Rectangular spatial coordinate system (OXYZ) assigned to the center O of the earth's ellipsoid (Fig. 2.3).
Rice. 2.3. System of rectangular spatial coordinates OXYZ.
E 0 - the point of intersection of the Greenwich meridian with the earth's equator.
The OZ axis is located on the polar axis of the ellipsoid 
; OX axis - in the plane of the equator and the prime (Greenwich) meridian RE 0 ;
OU axis - in the equatorial plane, but in the meridian RK, the plane of which makes an angle of 0 with the plane of the Greenwich meridian.
This system everything acquires coordinates higher value in geodesy in connection with the widespread introduction of so-called satellite measurements into the practice of geodetic work.
Plane rectangular coordinate system ( x, y).
In the countries of the former Union The national coordinate system is adopted in the Gauss–Kruger projection, which is obtained by projecting points of the earth's surface onto the side surface of the cylinder and unfolding it into a plane. This method made it possible to divide the entire surface of the Earth into areas of equal size, limited by meridians and extending in latitude from the North Pole to the South Pole (Fig. 2.4).
| at |
| X |
I love you very much leisure and try not to miss the opportunity to reconnect with nature! This year, when going on a hike through the forests of the Ukrainian Carpathians, I, first of all, decided to study navigation lessons and even then I discovered a new concept of azimuth. As it turns out, this is one of the most important concepts in orienteering, and it has quite a interesting origin.
What is azimuth
In simple words azimuth – the angle between the directions north and some distant object. He measured in degrees: 0° to 360°. Being able to determine the azimuth angle is worth a lot - it will help you not get lost, be able to navigate when moving in the mountains, in the forest, in deserts, in conditions of poor visibility and when it is difficult or impossible to navigate on the map. Derived from Arabic سمت (samt) - translated path, road, direction.
Origin of the word azimuth
In fact, quantityArabic words, actively used in the Russian language, can surprise any person. I was very surprised that even such familiar words as fur coat, shop and even skirt are of foreign origin and have Arabic roots.
At one time, the Arabs achieved significant advances in astronomy. For example, they developed rules for transition from one coordinate system to another, as well as options for determining the exact coordinates of celestial bodies. To carry out similar astronomical calculations and work, astronomers of the Islamic world developed terminology. Thus, the angle between a specially selected initial direction and the direction to a distant object is called azimuth of this object. In a similar way they determine azimuth of celestial bodies. This is how the word azimuth originated and began to be used in other areas.
The word azimuth is often used in everyday life. For example, I often hear the phrase “ in all azimuths”, which means in all directions, in all aspects.
How to determine azimuth using a compass
In practice it turned out to be quite simple:
Need to set the compass to flat surface;
After set the division scale so that both arrows on the compass coincide;
After we have oriented the compass, it is visually visible on its scale adjust the direction to the desired item.
Everything is simple, but infinitely important for any tourist, student, architect, military man or geographical worker. I hope you can now definitely answer the question what is azimuth, and that the information will be useful to you. :)
