3.Compass navigation - Compas de navigaţie

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Chapter 3:Compass navigation=Compas navigaie

Marine compass= Prognoza Compass

In China compasses have been in use since the Han dynasty (2nd centuryBCE to 2nd century CE) when they were referred to as south-pointers. Howeverat first these magnets were only used for geomancy much like in the art of FengShui.= n China compas au fost n uz din dinastia Han (secolul al 2lea BCE pentrua 2a secolul al CE), atunci cnd acestea au fost menionate n continuare "sud-indicatori". Cu toate acestea, la prima aceti magnei au fost folosite doar pentrugeomancy la fel ca n arta Feng Shui.

Eventually, during the Sung dynasty (1000 CE) many trading ships were thenable to sail as far as Saudi Arabia using compasses for marine navigation. Between1405 and 1433, Emperor Chu Ti's Treasure Fleet of the Dragon Throne ruled theentire South Pacific and the Indian Ocean, a territory that ranges from Korea andJapan to the Eastern coast of Africa. = n cele din urm, n timpul dinastiei Sung(1000 CE) nave de tranzacionare de multe au fost apoi n msur s navigheze nmsura n care Arabia Saudit folosind compasul pentru navigare marine. ntre1405 i 1433, Comoara mpratului Chu Ti's flot de pe tron Dragon condus

ntreaga Pacificului de Sud i Oceanul Indian, un teritoriu care se ntinde de laCoreea i Japonia, pn la coasta de est a Africii.

At this time Western mariners were still rather ignorant of the navigationaluse of the magnet. Petrus Perigrinus van Maricourt wrote a first treatise on themagnet itself: De Magnete (1269). And though its nautical use was alreadymentioned in 1187 by the English monk Alexander Neckham, the use onboard onlycame about around the 13th and 14th century in the Mediterranean Sea. =n acestmoment marinari de Vest au fost nc destul de ignorani cu privire la utilizarea denavigaie al unui magnet. Petrus Perigrinus van Maricourt a scris un tratat nprimul rnd pe magnetul n sine: "De Magnete" (1269). i dei utilizarea sa marinea fost deja menionat n 1187 de catre calugarul englez Alexandru Neckham, debord folosi doar despre a venit n jurul secolului al 14-lea i al 13-lea n MareaMediteran.

Much later, in 1545, Pedro de Medina (Sevilla 1493-1567) wrote the Spanishstandard work Arte de Navegar on marine compass navigation. This masterpiecewas first translated in Dutch (1580) and was -O Irony- used by Jacob vanHeemskerk when the Dutch destroyed the Spanish fleet near Gibraltar in 1607.
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The drawback was of course Van Heemskerk's own death during this victory.= Mult mai trziu, n 1545, Pedro de Medina (Sevilla 1493-1567) a scris lucrareaspaniol standard "Arte de Navegar" de la marin busola de navigare. Aceastcapodoper a fost tradus n limba olandez (1580) i a fost Ironia-O-utilizate deJacob van Heemskerk n cazul n care olandez a distrus flota spaniol napropierea din Gibraltar n 1607. Neajuns a fost, desigur, moartea Van Heemskerkproprii n aceast victorie.

Magnetic Variation= Variant magnetic

In the fin-de-sicle of the sixteenth century mariners believed that themagnetic north pole coincided with the geographic north pole. Any suggestionotherwise had been denied by Pedro de Medina. = n fin-de-sicle al marinarilorsecolului XVI crede c polul magnetic de nord a coincis cu Polul Nord geografic.

4 15' W 2009 (8' E) on the Magnetic North arrow means Magnetic Variation 4 15' W in 2009

annual change 8' E

(i.e. Magnetic Variation decreasing 8' annually to become 4 07' in 2010). Orice sugestie altfel ar


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fi fost refuzat de ctre Pedro de Medina.

Magnetic variation4 15' W 2009 (8' E) on the Magnetic North arrow means Magnetic Variation 4 15' W in 2009

annual change 8' E

(i.e. Magnetic Variation decreasing 8' annually to become 4 07' in 2010).

Magnetic observations made by explorers in subsequent decades showed

however that these suggestions were true. But it took until the early nineteenthcentury, to pinpoint the magnetic north pole somewhere in Arctic Canada (78 N ,104 W). From then on the angle between the true North and the Magnetic Northcould be precisely corrected for. This correction angle is called magnetic variationor declination. = Magnetice observaiile fcute de exploratori din ultimele deceniiulterioare au artat, totui, c aceste sugestii au fost adevrate. Dar a avut, pn la

nceputul secolului al XIX-lea, pentru a indica polul nord magnetic undeva n zonaarctic Canada (78 N, 104 W). De atunci unghiul dintre Nord adevrat i De
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Nord magnetic ar putea fi corectat pentru precizie. Acest unghi de corecie senumete magnetic variaia sau de refuz.

It is believed that the Earth's magnetic field is produced by electrical currentsthat originate in the hot, liquid, outer core of the rotating Earth. The flow of electriccurrents in this core is continually changing, so the magnetic field produced bythose currents also changes. This means that at the surface of the Earth, both thestrength and direction of the magnetic field will vary over the years. This gradualchange is called the secular variation of the magnetic field. Therefore, variationchanges not only with the location of a vessel on the earth but also varies in time.=Se crede c cmpul magnetic al Pamantului este produs de cureni electrici careprovin din cele fierbinte, lichid, Core exterioar a Pmntului prin rotaie. Fluxul decureni electrici n aceast baz se schimb continuu, astfel nct cmpul magneticprodus de cureni, de asemenea, aceste schimbri. Acest lucru nseamn c, lasuprafata Pamantului, att puterea i direcia cmpului magnetic va varia-a lungulanilor. Aceast schimbare treptat este numit Variaia secular a cmpuluimagnetic. Prin urmare, modificrile variaie nu numai cu amplasarea unei nave de

pe pmnt, dar, de asemenea, variaz n timp.

The correction for magnetic variation for your location is shown on thenearest! nautical chart's compass rose. In this example we find a variation of 4 15' Win 2009, with an indicated annual correction of 0 08' E. Hence, in 2011 thisvariation is estimated to be 3 59', almost 4 West. This means that if we sail 90on the chart (the true course), the compass would read 94. =De corecie pentruvariaie magnetice pentru locaia dvs. este afiat pe cel mai apropiat! busoldiagram nautice au crescut. n acest exemplu, vom gsi o variaie de W 4 15 'n2009, cu o corecie a indicat anuale de 0 08' E. Prin urmare, n 2011, aceastvariant este estimat a fi de 3 59 ', aproape 4 Vest. Acest lucru nseamn c,

dac vom naviga 90 pe diagram (curs adevrat), busola-ar citi 94 .

Another example: let's say the compass rose gives a variation of 2 50' E in2007, with a correction of 0 04' E per year. In 2009 this variation is estimated tobe 2 58', almost 3 East. Now, if we sail 90 on the chart, the compass would read87.= Un alt exemplu: sa spunem Compass Rose ofer o variaie de 2 50 'E n2007, cu o corecie de 0 04' E pe an. n 2009, aceast variant este estimat la 2 58 ', aproape 3 Est. Acum, dac vom interveni 90 pe diagram, busola-ar citi 87.

Correcting for variation= Corectarea de variaie
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These overlayed compass roses show the difference between true north andmagnetic north when the magnetic variation is 10 West. = Aceste trandafiriInnobilate busola arat diferena dintre nordul geografic i nord magnetic cazul ncare modificarea magnetic este de 10 Vest.

From the image we find: tc = cc + varin which cc and tc stand for compass course and true course, respectively.= De la imaginea gsim: TC = cc + var, n care "Cc"i"tc"Stand pentru" busola curs "i" desigur adevrat ", respectiv.

To convert a true course into a compass course we need first assign a -to a Western and a + to a Eastern variation. Note that this makes sense! becauseof the clockwise direction of the compass rose. Here, the inner circle is turned 10

anticlockwise, hence -10 . = Pentru a converti o Desigur adevrat ntr-uncompas curs avem nevoie de atribui n prima, o "-" la o Vest i un "+" la o variaiede Est. Reinei c acest lucru are sens! , din cauza sensul acelor de ceasornic aCompass Rose. Aici, cercul interior este pornit 10 anticlockwise, prin urmare,

--10 .

Now, use the same but re-written equation:cc = tc - var235 = 225 - (-10)So, to sail a true course of 225, the helmsman has to steer a compass course of235.

= Acum, utilizai la fel, dar re-ecuaia scris:CC = TC - var235 = 225 - (-10 )


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Deci, pentru a naviga un curs adevrat de 225 , crmaci trebuie s orienteze uncompas curs de 235 .

To convert a compass course into a true course we can use the originalequation. If we have steered a compass course of 200, we have to plot a truecourse of 203 in the chart if the variation is 3 East or a true course of 190 ifthe variation is 10 West . = Pentru a converti o compas desigur ntr-un cursde adevrat putem folosi ecuaia iniial. n cazul n care ne-am orientat uncompas curs de 200 , avem de a parcelei adevrat un curs de 203 n graficul devariaie n cazul n care este de 3 Est sau un curs adevrat de 190 n cazul ncare variaia este de 10 Vest .

Magnetic deviation= Deviere magnetic

Magnetic deviation is the second correctable error. The deviation error iscaused by magnetic forces within your particular boat. Pieces of metal, such as anengine or an anchor, can cause magnetic forces. And also stereo and other electricequipment or wiring, if too close to the compass, introduce errors in compassheading. = Abaterea magnetic este eroarea dou correctable. Abaterea de eroareeste cauzat de forele magnetice n termen de barca ta special. Piese de metal,cum ar fi un motor sau o ancor, pot cauza forelor magnetice. i, de asemenea,stereo i a altor echipamente electrice sau cablajul, dac sunt prea aproape decompas, s introduc erori n busola poziie.

Furthermore, the deviation changes with the ship's heading, resulting in adeviation table as shown below. The vertical axis states the correction in degreesWest or East, where East is again positive. =Mai mult, modificrile deviere cu navalui poziie, rezultnd ntr-un tabel deviaie dup cum se arat mai jos. Axa vertical,statele de corecie n grade Vest sau de Est, n cazul n care de Est este din noupozitiv.

The horizontal axis states the ship's heading in degrees divided by ten. Thus, whenyou sail a compass course of 220, the deviation is 4 W. (Note, that on most


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modern sailing yachts the deviation is usually not larger than 3). = Axa orizontalStatele navei la poziia n grade mprit la zece. Astfel, atunci cnd navigheaz uncompas curs de 220 , abaterea este de 4 W. (Reinei, c, la cele mai multeiahturi care navigheaz moderne abaterea este de obicei, nu mai mari de 3 ).

When a compass is newly installed it often shows larger deviations than thisand needs compensation by carefully placing small magnets around the compass. Itis the remaining error that is shown in your deviation table. = Atunci cnd o busoleste nou instalat-o de multe ori arat abaterile mai mare dect aceasta i arenevoie de compensare prin plasarea cu atenie i magneii de dimensiuni mici n

jurul busola. Este eroarea rmase, care este prezentat n tabelul de devieredumneavoastr.

You can check your table every now and then by placing your boat in the lineof a pair ofleading lights and turning her 360 degrees. = Putei verifica masa tafiecare acum i apoi prin plasarea barca dumneavoastr n linia de o pereche de

lumini de conducere si transformarea ei 360 de grade.

Correcting for both deviation andvariation=Corectarea att pentru devierea i devariaie

Converting a compass course into a true course, we can still use ourequation but we need to add the correction for deviation:cc + var + dev = tc

=Convertirea unei compas desigur ntr-un curs de adevrat, Putemfolosi n continuare ecuaia noastre, dar avem nevoie pentru a aduga corectarepentru devierea:CC + var + dev = TC

Example 1: The compass course is 330, the deviation is +3 (table) andthe variation is +3 (chart);330 cc + 3 var + 3 dev = ? tcgiving a true course of 336 which we can plot in our chart

=Exemplul 1: Compass curs este de 330 , abaterea este de 3 (tabelul), precum

i variaia este de 3 (grafic);330 cc + 3 var + 3 dev =? TCoferind un curs adevrat de 336 pe care le putem complot n diagram noastre

Example 2: The compass course is 220, the deviation is -4 (table) and thevariation is still +3 (chart).
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220 cc + 3 var + -4 dev = ? tc giving a true course of 219.

=Exemplul 2: Compass curs este de 220 , abaterea este de -4 (tabelul),precum i variaia este nc 3 (graficul).220 cc + 3 var + -4 dev =? TC

Example 3: The compass course is still 220, therefore the deviation is still-4 (table) but let's use a variation of -10 this time.220 cc + -10 var + -4 dev = ? tcgiving a true course of 206.

=Exemplul 3: Cursul Compass este nc 220 , prin urmare, abaterea este nc -4 (tabelul), dar hai sa utilizeze o variaie de la -10 acest timp.220 cc -10 + var + -4 dev =? TC oferind un curs adevrat de 206 .

Converting a true course into a compass course is a little less straightforward, but it is still done with the same equation. = Convertirea unei Desiguradevrat ntr-un compas curs este un pic mai puin drept nainte, dar este ncfcut cu aceeai ecuaie.

Example 4: The true course from the chart is 305 and the variation is +3(chart), yet we don't know the deviation;? cc + 3 var + ? dev = 305 tc

Luckily, we can rewrite this so this reads:cc + dev = 305 tc - + 3 var = 302

=Exemplul 4: Cursul adevrat din diagram este de 305 i variaia este de 3 (graficul), dar nu tim abaterea;? CC + 3 var +? dev = 305 TCDin fericire, putem rescrie acest lucru pentru acest prevede:CC + dev = 305 TC - + 3 var = 302

In plain English: the difference between the true course and the variation(305 - + 3) = 302 should also be the summation of the compass course and thedeviation. So, we can tell our helms person to steer 300, since with a cc of 300

we have a deviation of +2 (As can be deduced from the deviation table above). =n limba englez simplu: diferena dintre cursul adevrat i variaia (305 - + 3) =302 ar trebui s fie, de asemenea, nsumarea busol cursului i abaterea. Deci,putem spune persoana noastr Helms pentru a pilota 300 , deoarece cu un cc de300 avem o deviere de 2 (Dup cum se poate deduce din tabelul de abaterea demai sus).

Example 5: The true course from the chart is 150 and we have a Westernvariation of 7 degrees (-7). We will use the rewritten equation to get:


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150 tc - - 7 var = cc + dev = 157From the deviation table we find a compass course of 160 with a deviation of -3.

=Exemplul 5: Cursul adevrat din diagram este de 150 i avem o variaie deVest din data de 7 grade (-7 ). Vom folosi ecuaia rescrise pentru a obine:TC 150 - - 7 var = CC + dev = 157 Din tabelul de devierea vom gsi o busol curs de 160 , cu o deviere de -3 .Voil!

Magnetic course=Curs magnetic

sailingissues.com

The magnetic course (mc) is the heading after magnetic variation has beenconsidered, but without compensation for magnetic deviation. This means that weare dealing with the rewritten equation from above:

tc - var = cc + dev = mc.=The magnetic cursul (MC) este poziia dup ce variaia magnetic a fost luat

n considerare, dar fr compensaie pentru devierea magnetice. Acest lucrunseamn c avem de-a face cu ecuaia rescris de mai sus:TC - var = CC + dev = mc.

Magnetic courses are used for three reasons: =Cursuri de magnetice sunt utilizate

pentru trei motive:

1. To convert a true course into a compass course like we saw in the lastparagraph. = Pentru a transforma un curs adevrat ntr-un compas curs ca sicum am vzut n ultimul paragraf.

2. On vessels with more than one steering compass, also more deviation tables

are in use; hence only a magnetic or true course is plotted in the chart. = Penavele cu mai mult de o busola de direcie, de asemenea, mai multe tabeleabaterea sunt n uz, prin urmare, doar un curs de magnetice sau adevrateste n grafic n diagram.

3. Bearings taken with a handheld compass often don't require a correction fordeviation, and are therefore useful to plot in the chart as magnetic courses.= Palier luate cu un handheld compas de multe ori nu necesit o corecie
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pentru devierea i, prin urmare, sunt utile pentru complot n diagram icursuri de magnetice.

Note, that the actual course lines the navigator draws in the chart are always true

courses! These can subsequently be labeled with the true course or thecorresponding magnetic or compass course if appropriate. In the next chapter wewill be plotting courses in the chart. = Reinei, c liniile de real cursul Navigatoratrage n diagram sunt ntotdeauna cursuri de adevrat! Acestea pot fi, ulterior,etichetate cu cursul adevrat sau magnetice corespunztoare sau busol Desigur,dac este cazul. In capitolul urmtor vom fi trasarea cursuri n diagram.

To summarise, we have three types of north (true, magnetic and compass north)like we have three types of courses: tc, mc and cc. All these are related bydeviation and variation. = Pentru a rezuma, avem trei tipuri de "Nord" (adevrat,magnetic i busola nord) ca avem trei tipuri de cursuri: TC, MC i cc. Toate acesteasunt legate de deviere i de variaie.

Glossary

Maps with isogonic lines : =Harti cu linii isogonic :

World - overview 2000=World - privire de ansamblu 2000World - detailed 2000= World - detaliate 2000World - detailed 2005=World - detaliate 2005World - animated in time=World - animat n timp

Variation: The angle between the magnetic north pole and the geographicnorth pole. Also called the magnetic declination . = Variant: Unghiul dintre polulnord magnetic si Polul Nord geografic. De asemenea, numit Declinaie magnetic .

Secular variation: The change of magnetic declination in time with respectto both strength and direction of its magnetic field. = Variaie Secular: Schimbarede Declinaie magnetic n timp, att n ceea ce privete puterea i direcia dedomeniul su magnetic.

West (-) , East (+): Western variations or deviations are designated with anegative sign by convention due to the compass card's clockwise direction. =Occidentul (-) , East (+): Variaii de Vest sau abateri sunt desemnate cu un semn
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negativ, prin convenie, datorit compas direcia cardului sensul acelor deceasornic.

Deviation: The error in compass heading caused by electric magneticcurrents and or metal objects. = Deviaia: Eroare n Compass poziia cauzate decurenii magnetice i electrice sau obiecte de metal.

Deviation table: A table containing deviations in degrees versus the ship'sheading (compass course) in degrees. Usually plotted in a graph. =TabelulDeviaia: Un tabel care conine abateri n grade fa de poziia navei (compasdesigur), n grade. De obicei, reprezentate grafic ntr-un grafic.

True course: Course plotted in the chart i.e. course over the ground orcourse made good. The course corrected for compass errors. = BinenelesAdevarat: Curs grafic, n cursul adic graficul pe sol sau "curs fcut bine". Cursulcorectat pentru busola erori.

Compass course: The course (ship's heading) without the correction forcompass errors. = Desigur Compas: Curs (navei rubrica), fr de corecie pentrubusola erori.

cc + var + dev = tc: This equation shows the connection between thecompass course, its errors and the true course. It can also be read as: tc - var = cc+ dev. = CC + var + dev = TC: Aceast ecuaie arat legtura dintre cursul

busola, erorile sale i cursul de adevrat. Acesta poate fi citit, de asemenea, ca: TC- var = CC + dev.

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Geomagnetism
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Magnetic declination Geomagnetism Declinaie magnetic

Over much of the Earth's surface, compass needles point roughly north. However, because of thecomplex shape of the Earth's magnetic field there are few places where a compass needle willpoint exactly north. A compass lines up with the horizontal component(http://gsc.nrcan.gc.ca/geomag/field/comp_e.php)of the magnetic field in a direction called

magnetic north. True north, on the other hand is the direction from a given location to the northgeographic pole. The angle between magnetic north and true north is called magneticdeclination. Many people believe that a compass needle points at the North Magnetic Pole.(http://gsc.nrcan.gc.ca/geomag/field/arctics_e.php) This is not true; if you follow your compassneedle you will eventually arrive at the North Magnetic Pole, but not by the most direct route.Peste o mare parte din suprafaa Pmntului, busola ace punct de aproximativ nord. Cu toateacestea, din cauza formei complexe ale cmpului magnetic al Pamantului, exist cteva locuri ncazul n care un ac de busola va indica exact spre nord. O busol linii de sus cu componentorizontal a cmpului magnetic ntr-o direcie numit nord magnetic. Spre nord-adevr, pe de altparte este direcia de la o locaie dat la Polul Nord geografic. Unghiul dintre nordul magnetic inordul adevrat se numete Declinaie magnetic. Multi oameni cred ca un compas puncte deac, la Polul Nord magnetic. Acest lucru nu este adevrat, i dac vei urma dvs. de busol aculva ajunge n cele din urm la Polul Nord magnetic, dar nu i pe calea cea mai direct.

Terminology

Both declination and variation are used to describe the angle between magnetic north and truenorth. The term deviation is also used from time to time. Here is an explanation of thedifferences between the three terms. Ambele refuzate i variaie sunt folosite pentru a descrieunghiul dintre nordul magnetic i nord adevrat. Abaterea Termenul este folosit, de asemenea,din timp n timp. Aici este o explicaie a diferenelor ntre cele trei termeni.

Declination: This is the term preferred by those who study the magnetic field; it is also theterm most commonly used by land navigators. Sometimes the term "magnetic declination" isused. Acesta este termenul preferat de cei care studiu cmpul magnetic, este, de asemenea,termenul cel mai frecvent utilizate de ctre navigatori teren. Uneori, termenul de "Declinaiemagnetic" este folosit.

Variation: This term is preferred by mariners and pilots because the word "declination" also hasan astronomical usage - the angle of a star or planet above the celestial equator. However, theword "variation" is used by geomagneticians to refer to time changes in the magnetic field.Acest termen este preferat de marinari i piloi, deoarece cuvntul "refuz", de asemenea, are outilizare astronomic - unghiul de o stea sau planet de mai sus ecuatorul ceresc. Cu toateacestea, cuvntul "variaia" este folosit de geomagneticians pentru a se referi la schimbrile de

timp n cmpul magnetic.

Deviation: In a vehicle such as a ship or aircraft, a compass is influenced by the magnetism ofthe iron used in the construction of the vehicle as well as the Earth's magnetic field. This causesthe compass needle to point in the wrong direction. This directional error is called "deviation".Many people incorrectly use deviation when they mean declination. ntr-un vehicul, cum ar fi onav sau aeronav, un compas este influenat de magnetismul de fier utilizate n construciavehiculului, precum i cmpul magnetic al Pamantului. Acest lucru face ca acul busolei la punctul
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n direcia greit. Aceasta eroare de direcie se numeste "deviaie". Multe persoane utilizeaz nmod incorect, atunci cnd abaterea medie de refuz.

The first known determination of magnetic declination was made by the Chinese in about 720AD. In Europe, the concept of declination was known in the early 1400s, but the first precisemeasurement of declination was not made until 1510, when Georg Hartman determined the

declination in Rome. The importance of declination for navigation was obvious. Mariners quicklydevised methods for determining it and began compiling declination values from locations aroundthe world. In 1700 Edmund Halley came up with the idea of showing declination as contour lineson a map ; he used this novel concept to produced the first declination chart of the AtlanticOcean. Declination charts have been produced on a regular basis ever since. Determinareaprimul cunoscut de Declinaie magnetic a fost fcut de chinezi n aproximativ 720 AD. nEuropa, conceptul de refuz a fost cunoscut n anii 1400 la nceput, dar prima msurare precis aDeclinaie nu a fost fcut pn n 1510, cnd Georg Hartman determinat refuz de la Roma.Importana Declinaie pentru navigare a fost evident. Marinari rapid conceput metode de stabilirea acestuia i a nceput compilarea valorile Declinaie din locaii din ntreaga lume. n 1700Edmund Halley a venit cu ideea de a arta Declinaie ca linii de contur pe o hart, el a folositacest concept nou pentru a produs primul grafic Declinaie din Oceanul Atlantic. DiagrameleDeclinaie au fost produse n mod regulat de atunci.

Figure 16: Halley map Harta Halley

The secular variation(http://gsc.nrcan.gc.ca/geomag/field/sec_e.php) of the magnetic fieldcauses declination to change with time. Changes in declination can be quite large. At Yellowknife,NWT, for example, the declination is changing by more than one degree every three years. Onthe other hand, at Ottawa, the yearly change in declination is almost zero. The diagram showsthe change in declination at several locations in Canada. The Variaia secular a cmpuluimagnetic cauzele Declinaie pentru a schimba cu timpul. Modificri n declin pot fi destul de mari.
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La Yellowknife, NWT, de exemplu, Declinaie este n continu schimbare de mai mult de un gradla fiecare trei ani. Pe de alt parte, la Ottawa, se schimba anual n Declinaie este aproape dezero. Diagrama arat schimbare n declin n mai multe localiti n Canada.

Figure 17: Secular variation Variaia Secular

Magnetic declination also undergoes changes that are much more rapid than secularvariation and are a result ofmagnetic activity(http://www.spaceweather.gc.ca/svr-eng.php).These variations can be smooth and cyclic, with amplitudes of several minutes of arc in southernCanada, or, during magnetic storms, large and erratic. Declinaie magnetic, de asemenea,sufer schimbri, care sunt mult mai rapid dect variaie secular i sunt un rezultat almagnetice de activitate. Aceste variaii pot fi netede i ciclice, cu amplitudinile de mai multe

minute de arc n Canada de sud, sau, n timpul furtunilor magnetice, mari i neregulat.

Changes in declination become increasingly as one approaches the North Magnetic Pole,(http://gsc.nrcan.gc.ca/geomag/field/compass_e.php) a result of the weak horizontal componentof the magnetic field. The number of times per year that a compass user will be affected bychanges in declination caused by magnetic storms will depend both on the user's application andlocation. The diagram shows the percentage of days in a typical year during which magneticdeclination will fluctuate by more than a given amount from its normal value. Modificri ndeclin deveni din ce n ce ca fiind unul se apropie de Polul Nord magnetic, Un rezultat al slab
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component orizontal a cmpului magnetic. Numrul de ori pe an, pe care un utilizator busolvor fi afectate de schimbrile n Declinaie cauzate de furtunile magnetice va depinde att cuprivire la cererea utilizatorului i de locaie. Diagrama arat procentajul de zile ntr-un an tipic ncare Declinaie magnetic va fluctua cu mai mult de o anumit sum de la valoarea sa normal.

Figure 18: Probability of deviations Probabilitatea de abaterilarger image[GIF, 199.8 kb, 2177 X 1970, notice]

Most standard orienteering compasses have a precision of about 2 degrees. It can be seen thatin Southern Canada users of such compasses will seldom experience fluctuations larger than 2degrees. However, someone on a canoe trip in the NWT would find his or her compass in errorby more than 2 degrees on more than 1 day in 4. Cele mai multe orientare standard busole auo precizie de aproximativ 2 grade. Se poate observa c, n sudul utilizatorii Canada a busoleastfel de experienta rareori fluctuaii mai mari de 2 grade. Cu toate acestea, cineva intr-o
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excursie n canoe NWT s-ar gsi busola lui sau ei n eroare de ctre mai mult de 2 grade pe maimult de 1 zi, n 4.

How to determine declination

There are several ways for compass users to determine declination: Exist mai multe moduripentru a busola pentru a determina utilizatorii Declinaie:

From a map: ... Dintr-o hart:

Canadian topographic charts contain a diagram in the margin which gives the declination for theyear in which the chart was published. Beneath the diagram is a statement informing the userabout the annual change of declination. By multiplying the annual change by the number ofyears that have elapsed since the chart was published and adding the total change to the

published declination value, the user obtains the present day declination.

Canadian diagrameletopografice conin o diagram n marja de care d Declinaie pentru anul n care a fost publicatadiagrama. Sub diagrama este o declaraie a informa utilizatorul despre schimbarea anual derefuz. Prin nmulirea modificare anual cu numrul de ani care au trecut de la graficul a fostpublicat i adugarea de schimbarea total la valoarea publicat Declinaie, utilizatorul obinerefuz de azi.

Figure 19: Topo declination diagramTopo diagrama Declinaie


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Statement of magnetic declaration taken from Canadian topographic map: Declaraia dedeclaraie magnetice luate de la harta canadieni topografice:

"Magnetic declination 1992 varies from 1605 easterly at centre of west edge to 1403 easterlyat centre of east edge. Mean annual change decreasing 11.5.""Declinaie Magnetic 1992variaz de la 16 05 'est, de la centrul de margine de la vest la 14 03' est, de la centrul de

margine de est. Modificarea medie anual n scdere 11.5". "

Here is an example: Aici este un exemplu:

Declination in 1998: 13 15 W Declinaie n 1998: W 13 15 'Annual change: decreasing 5 Schimba anual: descresctoare a 5 '

Since the annual change is decreasing, treat it as negative. Therefore Declination in 2003 is:Avnd n vedere c modificare anual este n scdere, trata-o ca negativ. Prin urmare,Declinaie n 2003 este:

= 13 15 W - 5 x 5

= 13 15 W - 25= 12 50 W

It is important to remember that the annual change does not remain constant with time.Therefore, using the annual change to update the declination on an old map is likely to result inan error in the updated declination. Este important s ne amintim c schimbarea anual nurmn constante n timp. Prin urmare, folosind modificare anual de actualizare a Declinaie pe ohart veche este de natur s conduc la o eroare n refuz actualizat.

It is also important to know that the declination shown in the diagram on the topographic map isnot the true declination. Declination is defined as the angle between magnetic north and the truenorth. However, the diagram on the topographic map sheet gives the value of the angle betweenmagnetic north and grid north, which is referenced to the grid lines shown on the map. This

angle is properly called grid declination. The angle between grid north and true north is calledthe convergence angle. To obtain the true declination it is necessary to add or subtract theconvergence angle to the Grid Declination. The diagram illustrates four possible combinations.De asemenea, este important de tiut c Declinaie prezentat n diagrama de pe harttopografic refuz nu este adevrat. Declinaie este definit ca fiind unghiul dintre nordul magnetici nord adevrat. Cu toate acestea, diagrama pe foaia de hart topografic d valoarea deunghiul dintre nordul magnetic i nordul reelei, care se face referire la liniile grila afiat pehart. Acest unghi este numit n mod corespunztor refuz gril. Unghiul dintre nordul reea inord adevrat se numete unghiul de convergen. Pentru a obine Declinaie adevrat, estenecesar s se adauge sau scade unghiul de convergen pentru a Declinaie Grid. Diagramailustreaz patru combinaii posibile.


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Figure 20: grid (square), true (star) and magnetic north (arrow) gril (ptrat), adevrate(stele) i polul nord magnetic (sgeata)

In the diagram, n diagrama,

-the star indicates true north; the stea indica adevrat latitudine nordic;

-the square indicates grid north; the ptrat indica grila latitudine nordic;

-the arrow indicates magnetic north; the sgeata indica magnetic latitudine nordic;

-G refers to grid declination; G se refer la refuz reea;

-C is the convergence angle; C este unghiul de convergen;

-D refers to the declination. D. se refer la refuz.

All quantities are considered positive. Four cases are illustrated: Toate cantitile suntconsiderate pozitive. Patru cazuri sunt ilustrate:

1.Magnetic north west of true north; grid north west of true north; Magnetice la vest la nordde nord adevrat; gril nord-vest de nord adevrat;


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2.Magnetic north west of true north; grid north east of true north; Magnetice la vest la nord denord adevrat; gril nord-est de nord adevrat;

3.Magnetic north east of true north; grid north west of true north; Magnetice de nord-est de

nord adevrat; gril de nord vest de nord adevrat;

4.Magnetic north east of true north; grid north east of true north. Magnetic nord-est de nordadevrat; gril nord-est de nord adevrat.

Declination is also shown on aeronautical charts as contour lines and on hydrographic (marine)charts either as contour lines or in the form of a compass rose, depending on the scale of thechart. In all cases, true declination is given. Declinaie este, de asemenea, indicate pe hriaeronautice ca linii de contur i pe hidrografice (marin) diagrame fie ca linii de contur sau nform de compas a crescut, n funcie de scara a diagramei. n toate cazurile, Declinaie adevrateste dat.

From a magnetic declination chart: ... Dintr-o diagram Declinaie magnetic:

Natural Resources Canada produces a 1:10000000 scale chart showing lines of equal magneticdeclination and annual change over Canada. The charts are based on the Canadian GeomagneticReference Field, a mathematical model of the magnetic field produced every five years. Thelatest charts are for 2000. A simplified version of the chart is shown here. Natural ResourcesCanada produce o scar de 1:10000000 grafic care indic liniile de Declinaie egale magnetice ia schimbrilor anuale de peste Canada. Diagrame se bazeaz pe Canadian GeomagneticReference Field, Un model matematic al cmp magnetic produs la fiecare cinci ani. Cele mairecente diagrame sunt pentru anul 2000. O versiune simplificat a diagram este prezentat aici.
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Figure 21: simple D chart diagram simpl D

The complete chart, at a slightly reduced scale, may be downloaded in pdf format. Diagramcomplet, la o scar redus uor, pot fi descrcate n format pdf.

Charts of magnetic declination for the world are also available from the UK Hydrographic Office.

Grafice de Declinaie magnetic pentru nimic n lume sunt de asemenea disponibile de la MareaBritanie hidrografic Office.

From the declination calculator: ... De la calculator Declinaie:

The declination calculator is a simple an easy way to calculate up-to-date declination for anylocation on Earth. Simply enter the Year, Latitude and Longitude of your location and thedeclination calculator will give you the declination based on the latest magnetic reference fieldmodels. The Calculatorul declin este un simplu o modalitate simpl de a calcula up-to-Declinaie data pentru orice locaie de pe Pamant. Pur i simplu introducei An, longitudinea ilatitudinea locaia dumneavoastr i calculatorul Declinaie v va da refuz bazat pe cele mairecentemodele de referin cmp magnetic.
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