12.5 Compass Mode - Magnetic Declination
12.4 Compass Mode - Applications of the Compass
12.6 Compass Mode - Magnetic Declination Compensation
12.7 Compass Mode - Magnetic Declination at Major Cities
What is Magnetic Declination
!
!
! The angular difference between Magnetic North Pole
and True North Pole is called magnetic declination. Its
mag ni tud e (de g rees and m inut e s) a n d dir e ctio n
(easterly and westerly) depend on where you are in the
world.
!
! The Watch also includes a compensation setting for
Magne t i c D ec li na ti o n. Check t h e c o mi ng sectio n
"
for more details.
Magnetic Declination Information
! Most topographic maps include a small arrow which
s h o w s t h e m ag ne ti c n or th p o l e a n d m a gn et ic
declination information.
! For the benefit of the user, this m an u a l i n cl ud e s t he
magnetic declinations for some major cities. Check the
coming section 'Magnetic Declination at Major Cities'
for more details.
! For those cities, their names are not included on the
list, please check the online magnetic declination
information at:
1.http://www.geolab.nrcan.gc.ca/geomag/e_cgrf.html
2.Http://www.ngdc.noaa.gov/cgi-
bin/seg/gmag/fldsnth1.pl
The Magnetic North Pole is slightly different from the
True North Pole.
Th e WeatherMas ter, lik e most magneti c compa ss,
points to the Magnetic North Pole. On the contrary,
everything measured on a map is related to the True
North Pole.
For a serious compass user who intends to perform an
accurate navigation, the compass must be adjusted for
magnetic declination.
Calibrating the compass - Magnetic Declination Mode"
Check your position by Backward Bearing Directions
! Spot two distant identifiable landmarks like mountains,
light-house, fort or building from your current position,
for example the mountains A and B.
! Ch e ck o u t th e bac kwa r d bea rin g dir ecti ons o f
mountains A and B from your current position, for
exam p le 135 fro m moun t a in A a nd 270 fro m
mountain B.
! Use a ruler to draw a line 135 from the north at the
mountain A to your current position on the map. Draw
another line 270 from the north at the mountain B to
your current position on the map.
! You r cu r ren t pos iti o n on t he m a p wi l l be t he
intersection (point A) of the lines 1 3 5 from the
mountain A and 270
! Check the Trek Course Correctly
! During a trekking, the Watch can keep your course in
a correct way. For example, the correct trail starts
from point A and finishes at point E as drawn on the
adjacent map.
! Mark the points (identifiable landmarks) where the trail
turns its direction or the trail branches its way, such
as the points A, B, C, D and E on the adjacent map.
! Find out the bearing directions of point B from point A
(315 ), point C from point B (0 ), point D from point C
(225 ), and then point E from point D (315 ).
! During the trekking, make sure that the heading
direction is 315° from point A to point B. Performing
the similar checking in other sections of the trail
helps you keep your course correctly.
IMPORTANT: If you are in doubt of the directions and
positions of the trail, consult the park administration office
before starting the trekking.
° °
°
°
°
° from the mountain B.
° °
° °
Magnetic Declination Compensation
! To compensate for an object's bearing, either
subtract westerly (W) magnetic declination or add
ea st er l y( E) m a g ne ti c d ec l in at i o n w i th th e
magnetic bearing.
° °
° °
° °
° °
! Exa m ple 1 : West e rly m a gnet i c dec l inat i on
23°and the compass needle points 323°.
! TB = MB - W. When MB = 323 ; W =23
! TB = 323 - 23
! TB = 300°
! The true bearing is 300°.
! Example 2: Easterly magnetic declination 22°
and the compass needle points 278°.
! TB = MB + E. When MB = 278 ; E = 22
! TB = 278 + 22
! TB = 300°
! The true bearing is 300°.
! The Wat c h a llows y ou to co m pe nsate t h e
compass bearing at a place where the magnetic
dec l ination is e i ther Wes terly decli n ation or
Easterly declination.
! Chec k t he comin g s ec ti on "Cali b ra ti ng the
Compass" for more details of the setting.
Tru e No rth
Magn et ic
Decl in ation
Magn et ic
Decl in ation
Magn et ic
Nort h
4110 m
2120 m
3120 m
point A
(startin g point)
point B
A Sample Tr ail o n a Map
point D
point E
(finish po int)
point C
315°
225°
0°
315°
mountain B
Check Current Position By Backward Bearing
mountain A
270°
135°
point A
0
0
Compensa te th e Bearin g
with Weste rly (W) Mag netic Declin atio n
Compensa te th e Bearin g
with Easte rly (E ) Magnetic Declin atio n
Tru e Bearin g (TB) =
Magne ti c B earin g (MB) - Weste rly Magne ti c Decli nati on (W )
Tru e Bearin g (TB) =
Magne ti c B earin g (MB) + Easte rly Magneti c Declinati on (E )
300° (TB) = 27 8° (M B) + 22° (E )
300° = (M B) - 23 (W ) (TB) 323° °
magne tic
decli nat ion
23° W
magne tic
declinat ion
22° E
true
beari ng
300°
true
beari ng
300°
magne tic
beari ng
323°
magne tic
beari ng
278°
true north
0°
true north
0°
magnetic
north
magne tic
north
obje ct B
objec t B
point A
point A
No. Country/Place Major City Declination
1 Afghanistan Kabul +3E
2 Australia Canberra +12E
3 Austria Vienna +3E
4 Bahrain Manama +2E
5 Bangladesh Dhaka +0E
6 Belgium Brussels +0E
7 Brazil Brasilia -21W
8 Canada Ottawa -14W
9 Chile Santiago +3E
10 China Beijing -6W
11 China Hong Kong -2W
12 Costa Rica San Jose -1W
13 Cuba Havana -4W
14 Czech Republic Prague +3E
15 Denmark Copenhagen +3E
16 Egypt Cairo +4E
17 Finland Helsinki +8E
18 France Paris -1W
19 Germany Berlin +3E
20 Greece Athens +4E
21 Hungary Budapest +4E
22 India New Delhi +1E
23 Indonesia Jakarta +1E
24 Israel Jerusalem +4E
25 Italy Rome +2E
26 Japan Tokyo -7W
27 Jordan Amman +4E
28 Kenya Nairobi +0E
29 Korea Seoul -8W
30 Malaysia Kuala Lumpur +0E
31 Mexico Mexico City +6E
32 Nepal Kathmandu +0E
No. Country/Place Major City Declination
33 Netherlands Amsterdam +0E
34 New Zealand Wellington +22E
35 Norway Oslo +2E
36 Pakistan Islamabad +2E
37 Philippines Manila -1W
38 Portugal Lisbon -3W
39 Russia Moscow +10E
40 Singapore Singapore +0E
41 South Africa Cape Town -24W
42 Spain Madrid -2W
43 Sweden Stockholm +5E
44 Switzerland Bern +1E
45 Taiwan Tai-pei -4W
46 Thailand Bangkok -1W
47 UAE Abu Dhabi +2E
48 United Kingdom London -2W
49 United States Washington, DC -11W
50 United States Juneau +22E
51 United States Phoenix +11E
52 United States Little Rock +1E
53 United States Sacramento +14E
54 United States Denver +9E
55 United States Atlanta -4W
56 United States Honolulu +10E
57 United States Boston -15W
58 United States Saint Paul +1E
59 United States Jackson +0E
60 United States Santa Fe +9E
61 United States Oklahoma City +5E
62 United States Salem +16E
63 United States Harrisburg -11W
64 United States Salt Lake City +12E
NOTE: Since magnetic declinations will be changed with time, it is recommended to check the updated data from following sites:
http://www.magnetic-declination.com/ & http://www.ngdc.noaa.gov/geomagmodels/Declination.jsp
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