DMS vs UTM

[Peakbagr]

What is your preference for map and GPS coordinates and why:
DMS(degrees, minutes, seconds) or UTM (universal transverse mercator) ?

GPS mapping programs and units default to DMS. Most map references I see here, in guidebooks, and in correspondence use DMS.
I posed this question to a friend and he likened DMS to data CDs and UTM to DVDs in his analogy.

I'm a DMS user, but what do you prefer and is UTM the next and better representation?

Thanks,
Alan

 

[SAR-EMT40]

While the whole thread is worth reviewing this was my contribution last year on this subject. Search for the keyword 'avast' to see the entire thread.

Just a small correction I'd make. The Army actually uses MGRS (Military Grid Reference Sytem) which is identical to the UTM between 80deg S and 85deg N except it uses a different labeling system. Both systems have the ability to change the length of the coordinate representation depending on the resolution that is needed i.e. 1000 meter grid square or 100 resolution or 10 meter resolution even 1 meter resolution can be represented but probably has little meaning and I have never seen used. This is very handy.

I couldn't agree more with SARdog1. The Military has been using MGRS for many, at least 45 years that I am aware of. MGRS, UTM, USNG are all based on meters or kilometers if you prefer. Use of them couldn't be easier. UTM is the civilian equivalent of MGRS and unless you say things like avast ye mates and Arrrhhh or you fly around then the coordinate system for you is UTM.

There is also the USNG (United States National Grid) which is required to be used by federal/state/local agencies to geocode most things now. Again, this is very similar to UTM.

So, UTM if you are working on the ground. DMS if you fly or spend time on the water.

My $.02,
Keith

 

[sardog1]

So, UTM if you are working on the ground. DMS if you fly or spend time on the water.

My $.02,
Keith

Yeah, what he said. (And it's worth a lot more than he's pricing it at.) Take a look at Selecting a Geographic Coordinate System and the related links for some very good discussion and tutoring on this subject.

 

[DougPaul]

DMS is generally preferred for aeronautical and nautical navigation. It treats the earth as a sphere and covers the entire earth with a single coordinate system.

UTM is a simplified system for land use. It breaks the surface of the earth into a large number of small sections and treats each one as a plane using meters as the coordinate units. (Coordinates must include a section specifier.) So it is only accurate over small distances.

I have some nautical navigation in my background and thus prefer d.dd, dm.mm, or dms, whichever others (that I am communicating with) are using (ie whichever minimizes my format conversions). I also prefer the simplicity of one system that works everywhere. FWIW, my GPS and computer software are currently set to dm.mm.

One should use whatever system is in use by the environment, coworkers, and/or companions to minimize conversion errors and confusion. Otherwise, it is personal choice--ultimately both systems work.

GPSes use d.dd and WGS-84 internally (and in .gpx files) and covert to the chosen format for display to the user.

IMO, rescue services, no matter what they use internally, should be able to accept any coordinate format and datum from victims and translate it to their internal format.

As others noted, we have discussed this topic before...

Doug

 

[Puck]

One should use whatever system is in use by the environment,
Doug

I volunteer for a bird census. My oint locations are in the degree decimal format but then they ask for the UTM map number...I guess one can have the best of both worlds, you can give KM/L or you can give rods/hogshead.

 

[DougPaul]

I volunteer for a bird census. My oint locations are in the degree decimal format but then they ask for the UTM map number...I guess one can have the best of both worlds, you can give KM/L or you can give rods/hogshead.

Fortunately, locations specified in one coordinate system can easily be converted to any other by computer program... (And GPSes allow one to specify any of a large number of formats and datums for I/O.)

Doug

 

[Puck]

Fortunately, locations specified in one coordinate system can easily be converted to any other by computer program... (And GPSes allow one to specify any of a large number of formats and datums for I/O.)

Doug

My GPS can go from one system to another. It reminds me of General Chmestry, there were exercises to convert from Fahrenheit to Celsius but the reality is you live in one world or the other.

 

[J.Dub]

My GPS can go from one system to another. It reminds me of General Chmestry, there were exercises to convert from Fahrenheit to Celsius but the reality is you live in one world or the other.

Actually, the reality is that we live in one world with two different ways* to describe its temperature...




*Doug, I'm ignoring the Kelvin scale on purpose here. <wink>

 

[Stash]

..and I still don't understand why they got rid of LORAN.

 

[DougPaul]

*Doug, I'm ignoring the Kelvin scale on purpose here. <wink>

No Rankine?

Doug

 

[RoySwkr]

GPS mapping programs and units default to DMS. Most map references I see here, in guidebooks, and in correspondence use DMS.

Most references I see are DD MM.MMM, so I use it although I prefer DD.DDDD for brevity.

Didn't we have this discussion earlier this year?

 

[SAR-EMT40]

Didn't we have this discussion earlier this year?

That is where my comments came from. I quoted myself. I'm so efficient.

Keith