What is the Singapore's longitude/latitude ?

lsy_98 · Post by **lsy_98** » Wed Mar 03, 2004 1:05 pm

I've downloaded a sky chart software but required some information to locate for Singapore location. Anyone can help ?
1) Longitude (o ' " E)
2) Latitude (o ' " N)
3) Altitude (m)
4) Time zone (hrs E)

I just brought a EQ3-2 mount. Anyone can teach me how to set the Polar alignment ? What is the polar degree when scope is at Singapore and Kuala Lumpur ?

Thanks in advance.

addy · Post by **addy** » Wed Mar 03, 2004 1:47 pm

1) Longitude (o ' " E) = +103 deg 49' 30" East
2) Latitude (o ' " N) = 01 deg 17' 56" North
4) Time zone (hrs E) = UTC + 8.0

Found an interesting page at this site http://homepage.mac.com/stingerx/waypoints.htm

regards
Addy

chrisyeo · Post by **chrisyeo** » Wed Mar 03, 2004 7:27 pm

Does anyone know what the magnetic deviation is for Singapore? Or does magnetic north correspond nicely to true north for us?

regards
Chris

Post by **acc** » Wed Mar 03, 2004 8:09 pm

They correspond very closely in Singapore...

newbgalore2 · Post by **newbgalore2** » Thu Jun 17, 2004 12:56 pm

magnetic north is 11 degrees away from true north. The closest way to find true north for astronomers, is to find polaris, which is 40+ arc seconds away from true north. Due to precession, polaris will approach true north at its closest at around 20+arc seconds.

Post by **acc** » Thu Jun 17, 2004 9:29 pm

newbgalore2 wrote:magnetic north is 11 degrees away from true north.

Hi
Wondering where you obtained this info from? Magnetic deviatoin varies by locality; in Singapore, it should be less than 1 deg.

cheers
cc

newbgalore2 · Post by **newbgalore2** » Thu Jun 17, 2004 10:17 pm

acc wrote:
newbgalore2 wrote:magnetic north is 11 degrees away from true north.
Hi
Wondering where you obtained this info from? Magnetic deviatoin varies by locality; in Singapore, it should be less than 1 deg.

cheers
cc

Actually, magnetic deviation varies about 11 degrees at the poles. This im very sure about. I'm not sure about Singapore, but could you explain why magnetic deviation varies by locality? thnx.

Post by **weixing** » Thu Jun 17, 2004 11:01 pm

Hi,

Actually, magnetic deviation varies about 11 degrees at the poles. This im very sure about.

I was just wondering... since you are on the poles, the north should be on your feet, so 11 degree from where... Just kidding...

I'm not sure about Singapore, but could you explain why magnetic deviation varies by locality?

Since magnetic north and true north is not the same, so it will points at some angle east or west of true north depend on where you are.

By the way, the motion of the molten metallic fluid in the outer core of the Earth causes the magnetic field to change slowly with time, so the magnetic declination does not remain constant over time.

Go to this website ( http://www.geolab.nrcan.gc.ca/geomag/magdec_e.shtml ) for more information and also got a page to calculate the magnetic declination ( http://www.geolab.nrcan.gc.ca/geomag/mirp_e.shtml ) for you... just give the Latitude and Longitude and it will return you the magnetic declination. I submit Singapore coordinate and the answer is: 0º 13' E

Hope it is useful to those who are interested.

Have a nice day.

newbgalore2 · Post by **newbgalore2** » Fri Jun 18, 2004 1:19 pm

Ok, i found out: no matter where you are on earth, magnetic north is still 11 degrees away from true north. I read this in an astronomy textbook. If you are standing on the poles, magnetic north is 11/360 X pi X 2 X (6378)= 1224.5 km away. which means that astronomers cant really use a compass to gauge where truely are, so they have to use polaris as a gauge(much more accurate). To put it in a situation, if you are standing 3 cm away from the north pole, yr compass will point to a place 1225 km away, not the north pole itself!

As for changing magnetic field, as quoted from scientific american:

The time between magnetic reversals on the Earth is sometimes as short as 10,000 years and sometimes as long as 25 million years; the time it takes to reverse is only about 5,000 years

magnetic declination changes with because the magnetic field is changing due to secular variation, but the value i read in the textbook was 11 degrees. it changes all the while, actually. I'm not sure why my book quoted the value anyway, it didnt state when the value was taken

Post by **weixing** » Fri Jun 18, 2004 3:40 pm

Hi,

Ok, i found out: no matter where you are on earth, magnetic north is still 11 degrees away from true north. I read this in an astronomy textbook. If you are standing on the poles, magnetic north is 11/360 X pi X 2 X (6378)= 1224.5 km away. which means that astronomers cant really use a compass to gauge where truely are, so they have to use polaris as a gauge(much more accurate). To put it in a situation, if you are standing 3 cm away from the north pole, yr compass will point to a place 1225 km away, not the north pole itself!

May I know which textbook are you reading??? May be you misunderstood what the textbook is trying to explain.

Anyway, if I stand I'm in a position that form a straight line from true north to magnetic north, what is my magnetic declination??? 0 degree. So it is incorrect to said that magnetic north is always 11 degree away from true north no matter where you are on earth.

Have a nice day.