Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
Isogonic Lines  
User currently offlinemawingho From Hong Kong, joined Jul 2012, 41 posts, RR: 0
Posted (2 years 2 months 3 weeks 5 days 19 hours ago) and read 3643 times:

From Wikipedia http://en.wikipedia.org/wiki/Magnetic_variation

"Magnetic declination is the angle between magnetic north (the direction the north end of a compass needle points) and true north. The declination is positive when the magnetic north is east of true north. The term magnetic variation is a synonym, and is more often used in navigation. Isogonic lines are where the declination has the same value, and the lines where the declination is zero are called agonic lines."

I still do not quite understand the last sentence about Isogonic Lines, anyone knows?

10 replies: All unread, jump to last
 
User currently offlinevikkyvik From United States of America, joined Jul 2003, 10137 posts, RR: 26
Reply 1, posted (2 years 2 months 3 weeks 5 days 19 hours ago) and read 3627 times:
Support Airliners.net - become a First Class Member!

Quoting mawingho (Thread starter):
Isogonic lines are where the declination has the same value, and the lines where the declination is zero are called agonic lines."

Sounds like isogonic lines are the set of continuous points where the magnetic variation stays constant.

So if you start somewhere with a magnetic variation of, say, +5 degrees, then the line you follow to maintain a magnetic variation of +5 degrees is an isogonic line.



"Two and a Half Men" was filmed in front of a live ostrich.
User currently offlinebond007 From United States of America, joined Mar 2005, 5432 posts, RR: 8
Reply 2, posted (2 years 2 months 3 weeks 5 days 19 hours ago) and read 3626 times:

Agonic lines are simply joining points where the declination is zero ... i.e. no difference between true and magnetic.

A compass will point to true North on this line.

Jimbo

[Edited 2012-08-06 09:54:07]


I'd rather be on the ground wishing I was in the air, than in the air wishing I was on the ground!
User currently onlineMir From United States of America, joined Jan 2004, 21730 posts, RR: 55
Reply 3, posted (2 years 2 months 3 weeks 5 days 13 hours ago) and read 3527 times:

If you're familiar with contour lines on a map, isogonic lines use the same principle. Just like every point on a contour line has the same altitude, every point on an isogonic line has the same magnetic variation.

-Mir



7 billion, one nation, imagination...it's a beautiful day
User currently offlinebond007 From United States of America, joined Mar 2005, 5432 posts, RR: 8
Reply 4, posted (2 years 2 months 3 weeks 5 days 12 hours ago) and read 3511 times:

Quoting Mir (Reply 3):
If you're familiar with contour lines on a map

... or weather of course, showing the pressure with isobars ... iso meaning 'equal'


Jimbo



I'd rather be on the ground wishing I was in the air, than in the air wishing I was on the ground!
User currently offlineSlamClick From United States of America, joined Nov 2003, 10062 posts, RR: 68
Reply 5, posted (2 years 2 months 3 weeks 5 days 11 hours ago) and read 3502 times:

isotherms
isotachs
isopleths



Happiness is not seeing another trite Ste. Maarten photo all week long.
User currently offlineStarlionblue From Greenland, joined Feb 2004, 17079 posts, RR: 66
Reply 6, posted (2 years 2 months 3 weeks 5 days 11 hours ago) and read 3493 times:

Here's an example of isogonic lines in the United States. As mentioned magnetic variation is the same along the lines.

Quoting SlamClick (Reply 5):

isotherms
isotachs
isopleths

isohyets.



"There are no stupid questions, but there are a lot of inquisitive idiots."
User currently offlineRara From Germany, joined Jan 2007, 2123 posts, RR: 2
Reply 7, posted (2 years 2 months 3 weeks 4 days 3 hours ago) and read 3271 times:

Quoting Starlionblue (Reply 6):
isohyets

isobronts  



Samson was a biblical tough guy, but his dad Samsonite was even more of a hard case.
User currently offlineSlamClick From United States of America, joined Nov 2003, 10062 posts, RR: 68
Reply 8, posted (2 years 2 months 3 weeks 3 days 22 hours ago) and read 3228 times:

Quoting Rara (Reply 7):
isobronts

isocubes: Line connecting points in a chilled beverage where freezing temperatures occur.



Happiness is not seeing another trite Ste. Maarten photo all week long.
User currently offlineKELPkid From United States of America, joined exactly 9 years ago today! , 6421 posts, RR: 3
Reply 9, posted (2 years 2 months 3 weeks 3 days 15 hours ago) and read 3168 times:

Quoting SlamClick (Reply 8):
Quoting Rara (Reply 7):
isobronts

isocubes: Line connecting points in a chilled beverage where freezing temperatures occur.

isolate    (myself from this thread!)



Celebrating the birth of KELPkidJR on August 5, 2009 :-)
User currently offlinevikkyvik From United States of America, joined Jul 2003, 10137 posts, RR: 26
Reply 10, posted (2 years 2 months 3 weeks 3 days 15 hours ago) and read 3159 times:
Support Airliners.net - become a First Class Member!

isohorny.

i managed to make myself laugh and grimace at the same time with that one.



"Two and a Half Men" was filmed in front of a live ostrich.
Top Of Page
Forum Index

Reply To This Topic Isogonic Lines
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
No Lines Marking Edge Of Runway At YUL? posted Fri Jul 30 2010 09:08:49 by Evan767
Runway Lines In Canada posted Wed Jun 9 2010 19:11:39 by StarAC17
Color Codes On Fuel Lines For Comercial Aircraft posted Sat Mar 8 2008 13:42:47 by Suisjes
Kalman Filter/curved Lines posted Thu Mar 1 2007 17:07:59 by Diego
Hydraulic Lines Run Through Passenger Section? posted Sun Aug 27 2006 19:26:29 by CTR
Lines On Top Of The Door posted Mon Oct 31 2005 02:10:06 by Kaitak744
Hydraulic Fittings And Lines posted Mon Sep 5 2005 23:07:55 by Radialman
Rising Window Lines At A330/340/310/300 posted Sat May 7 2005 23:01:29 by Glidepath73
Hold Short Lines :/ posted Thu Apr 29 2004 00:53:11 by Planespotting
Lines Above The Doors... posted Thu Sep 25 2003 01:43:26 by AA7771stClass

Sponsor Message:
Printer friendly format