Why The Hell... (random rant)

wrote:


Astro navigation, but it's still an angle away from a standard
vector. So different sciences are using the same word with different
meanings.

However, you're of course correct that for magnetic navigation,
declination and variation are the same thing.

http://www.ngdc.noaa.gov/seg/geomag/faqgeom.shtml

Kev


Thanks to you, farr1220, and Peter. I always wondered in the back of my
mind how the term declination came to mean variation. Now I'm ready to
navigate the outer space :-)

"RomeoMike" wrote in message
...


wrote:


Astro navigation, but it's still an angle away from a standard
vector. So different sciences are using the same word with different
meanings.

However, you're of course correct that for magnetic navigation,
declination and variation are the same thing.

http://www.ngdc.noaa.gov/seg/geomag/faqgeom.shtml

Kev


Thanks to you, farr1220, and Peter. I always wondered in the back of my
mind how the term declination came to mean variation. Now I'm ready to
navigate the outer space :-)

Hmmmm. I see that what I have been calling declination is called
inclination on the NOAA site, so I will correct as appropriate.

In view of my recollections of ground school, I believe that it might be
least confusing to continue using the term deviation for the instrument
error as installed, variation for the difference between true and magnetic
north, and inclination for the angle between the lines of force and the
horizontal--leaving the term declination unused.

Peter
(Planning to think about this at leisure)

"Peter Dohm" wrote in message
.. .

In view of my recollections of ground school, I believe that it might be
least confusing to continue using the term deviation for the instrument
error as installed, variation for the difference between true and magnetic
north, and inclination for the angle between the lines of force and the
horizontal--leaving the term declination unused.


You could use declination for the difference between the magnetic variation
a VOR is set to and the actual local magnetic variation.

On Apr 6, 8:56 am, "Peter Dohm" wrote:
"RomeoMike" wrote in message

...





wrote:

Astro navigation, but it's still an angle away from a standard
vector. So different sciences are using the same word with different
meanings.

However, you're of course correct that for magnetic navigation,
declination and variation are the same thing.

http://www.ngdc.noaa.gov/seg/geomag/faqgeom.shtml

Kev

Thanks to you, farr1220, and Peter. I always wondered in the back of my
mind how the term declination came to mean variation. Now I'm ready to
navigate the outer space :-)

Hmmmm. I see that what I have been calling declination is called
inclination on the NOAA site, so I will correct as appropriate.

In view of my recollections of ground school, I believe that it might be
least confusing to continue using the term deviation for the instrument
error as installed, variation for the difference between true and magnetic
north, and inclination for the angle between the lines of force and the
horizontal--leaving the term declination unused.


Yes and then aviators would be in perfect alignment with ocean
naavigators who use variation and deviation. The conversion from true
to compass heading makes a nice nemonic:

timid virgins make dull company

for TRUE (variation) MAGNETIC (deviation) COMPASS

Cheers MC

Thanks to you, farr1220, and Peter. I always wondered in the back of
my
mind how the term declination came to mean variation. Now I'm ready to
navigate the outer space :-)

Hmmmm. I see that what I have been calling declination is called
inclination on the NOAA site, so I will correct as appropriate.

In view of my recollections of ground school, I believe that it might be
least confusing to continue using the term deviation for the instrument
error as installed, variation for the difference between true and
magnetic
north, and inclination for the angle between the lines of force and the
horizontal--leaving the term declination unused.


Yes and then aviators would be in perfect alignment with ocean
naavigators who use variation and deviation. The conversion from true
to compass heading makes a nice nemonic:

timid virgins make dull company

for TRUE (variation) MAGNETIC (deviation) COMPASS

Cheers MC

That's the nemonic that I was taught--and then forgot. :-(

Peter

Peter Dohm wrote:

In view of my recollections of ground school, I believe that it might be
least confusing to continue using the term deviation for the instrument
error as installed, variation for the difference between true and magnetic
north, and inclination for the angle between the lines of force and the
horizontal--leaving the term declination unused.

Peter
(Planning to think about this at leisure)



I suppose that the term declination would better be unused in favor of
"variation" in the context of defining the difference between magnetic
and true north, and in my experience it is unused in aviation.
Unfortunately, it is used on government issued topo maps and in some
orienteering books and by some orienteering compass makers, who tell one
to enter the "declination" into the compass card so that the needle
points to true north. Inclination is another term with different meaning
in different contexts.

RomeoMike wrote:



I suppose that the term declination would better be unused in favor of
"variation" in the context of defining the difference between magnetic
and true north, and in my experience it is unused in aviation.
Unfortunately, it is used on government issued topo maps and in some
orienteering books and by some orienteering compass makers, who tell one
to enter the "declination" into the compass card so that the needle
points to true north. Inclination is another term with different meaning
in different contexts.


OK, before I get flamed, I know that the compass needle always points to
magnetic north, but on an orienteering compass the "declination" is set
in the compass card so that the north indication is under the needle.

RomeoMike writes:

OK, before I get flamed, I know that the compass needle always points to
magnetic north ...

Actually it always aligns with the magnetic field in which it is placed, which
often means that it points roughly to magnetic north, but not always, as the
geomagnetic field is quite irregular.

--
Transpose mxsmanic and gmail to reach me by e-mail.

"RomeoMike" wrote in message
...


Peter Dohm wrote:

In view of my recollections of ground school, I believe that it might be
least confusing to continue using the term deviation for the instrument
error as installed, variation for the difference between true and
magnetic
north, and inclination for the angle between the lines of force and the
horizontal--leaving the term declination unused.

Peter
(Planning to think about this at leisure)



I suppose that the term declination would better be unused in favor of
"variation" in the context of defining the difference between magnetic
and true north, and in my experience it is unused in aviation.
Unfortunately, it is used on government issued topo maps and in some
orienteering books and by some orienteering compass makers, who tell one
to enter the "declination" into the compass card so that the needle
points to true north. Inclination is another term with different meaning
in different contexts.

I'm comfortable with "variation" because that's what I learned, but believe
that you are probably right.

BTW, you sent me to the dictionary for "orienteering"

Peter