Any advantage of the DMS system over the Decimal Degree?

Hello, All:

The Degree-Minute-Second (DMS) system is widely used in geographic
coordinates in many places. Google Earth and Wikipedia (in entries of
places) are just two ready examples. However, it is pretty much
annoying to make notes of the latitude and longitude of a place in the
DMS system or to copy/paste them for various purposes. And when you
use the latitude and longitude as inputs for some kind of
trigonometric computation, you need to convert them to decimal
degrees.

So I am wondering if the DMS system has real advantages over the
decimal degree in today's world. Who are the people that would prefer
the DMS system to the latter?

Thank you for reading!

--Roland

qquito wrote:


Personally, I prefer decimal degrees over DMS simply because there's
less cutting and pasting to do. If I have that luxury of course.

For the end user, I really can't see any advantage over any other,
other than perhaps if they had one device or software interface that had
limited decimal resolution, where the DMS option may offer a higher
location resolution. But that's just a software limitation.

Past that point though, there would be little to argue about regarding
advantage, mainly because all my devices and applications can cater for
pretty much anything.

From a data supplier perspective, one could speculate that database
might be smaller, or easier to deal with if they stored locations in one
format over another. But even that would be a rather weak argument.


Perhaps it would be more important to state a device, software or other
interface *should* offer all the format variations for convenience,
rather than for any particular technical advantage.
--
I'm not smart enough to lie - Ronald Reagan

On 15/01/2011 00:57, John Tserkezis wrote:

and what about hybrid notation, my Nokia displays lat & long as
degrees'minutes'seconds.decimal-seconds ie 52'24'32.45
really it doesn't matter as long as every application you use can be set
to the same format.

On Fri, 14 Jan 2011 14:39:27 -0800 (PST), qquito wrote:


Older people? Degrees, minutes, and seconds were almost
exclusively used 50 or more years ago.

And, no doubt, a mathematician would always prefer degrees with
decimal degrees for its purity, clarity, and simplicity.

But to complicate matters, the default today is neither; it is
degrees and minutes with decimal minutes. The reason is quite
rational---this enables you to determine coordinates from maps
more easily.

The reason for this, in turn, is that on a meridian (and along
the equator) one minute is one nautical mile, so, for example,
to travel 27.5 degrees north, you have to travel 27.5 nautical
miles north.

That is why maps, particularly modern, GPS-friendly ones, show
minutes, and that is why you are best off, when calling an
emergency help vehicle, dictating your position in degrees and
minutes with decimal minutes, like this:

"North fourty-eight degrees, three decimal seven eight minutes,
east eleven degrees, fourty-one decimal six seven minutes"

(For precision to a few meters you want three decimals, not
two.)

Of course, anyone well trained in emergency or search and rescue
operations will be able to take coordinates in any of the three
common formats. So if you need help very urgently and have your
GPS set to the "wrong" format, read it out anyway and ask if it
is understood. On the other hand it cannot hurt having your GPS
set to the default format of ddd mm.mmm as a precaution.

Hans-Georg

wrote (with clarity & insight):


I think the only time DMS would appeal to any real world user would be
when trying to transfer coordinates verbally, perhaps over a radio
link - only because the extra words involved (the D, M & S) set a
sequence that numbers alone won't.

It's tough being confident that an error didn't creep into any verbal
handoff of coordinates, and numbers-only seems like the most
error-prone to me.

Isn't DMS probably nothing more than a legacy of transits & sextants?