Previous :: Next Topic |
Author |
Message |
Navy salad Member
Joined: 09 Sep 2008 Posts: 1864 | TRs | Pics Location: Woodinville |
Anyone know why UTM coordinates are given with the East/West coordinate (ie the equivalent of Longitude) first and the North/South coordinate (the equivalent of Latitude) second, when traditional non-UTM point locations are just the reverse (ie, Latitude first, then Longitude)?
I like UTM, but this has tripped me more than once!
|
Back to top |
|
|
Anne Elk BrontosaurusTheorist
Joined: 07 Sep 2018 Posts: 2410 | TRs | Pics Location: Seattle |
|
Anne Elk
BrontosaurusTheorist
|
Sat Jun 22, 2019 3:17 pm
|
|
|
"There are yahoos out there. It’s why we can’t have nice things." - Tom Mahood
|
Back to top |
|
|
Bernardo Member
Joined: 08 Feb 2010 Posts: 2174 | TRs | Pics Location: out and about in the world |
|
Bernardo
Member
|
Sat Jun 22, 2019 9:05 pm
|
|
|
I think it's because the X variable is independent and the Y variable is dependent. It's much more intuitive to go over then up when plotting a location using coordinates. Makes calling in artillery much easier. Just my hunch.
|
Back to top |
|
|
Vertec Member
Joined: 08 Sep 2018 Posts: 159 | TRs | Pics
|
|
Vertec
Member
|
Thu Jul 04, 2019 6:31 pm
|
|
|
UTM is a "flattened" map projection which "divides" longitude into zones, so the zone with its E/W coordinate appears first. This made filing paper maps easier. UTM zones each span 6 degrees of longitude so the numeric range of E/W is potentially smaller.
Out There, carrying the self-evident truth I am endowed by my Creator with unalienable rights of self-defended Life, Liberty, and the pursuit of Happiness.
Out There, carrying the self-evident truth I am endowed by my Creator with unalienable rights of self-defended Life, Liberty, and the pursuit of Happiness.
|
Back to top |
|
|
Brian Curtis Trail Blazer/HiLaker
Joined: 16 Dec 2001 Posts: 1696 | TRs | Pics Location: Silverdale, WA |
FWIW, I write a fair amount of code that uses lat/long and the order is typically longitude than latitude. It is because, as Bernardo said, x (horizontal) then y (vertical) is the standard for most calculations.
that elitist from silverdale wanted to tell me that all carnes are bad--Studebaker Hoch
that elitist from silverdale wanted to tell me that all carnes are bad--Studebaker Hoch
|
Back to top |
|
|
InFlight coated in DEET
Joined: 20 May 2015 Posts: 847 | TRs | Pics Location: Seattle area |
|
InFlight
coated in DEET
|
Fri Jul 05, 2019 8:02 am
|
|
|
All the USGS, National Geographic, and Green Trail primary map grid lines are in UTM. They include DMS Tick Marks along each axis as well. When using paper maps, UTM coordinates are simply easier.
“I went to the woods because I wished to live deliberately...” ― Henry David Thoreau
“I went to the woods because I wished to live deliberately...” ― Henry David Thoreau
|
Back to top |
|
|
hbb Member
Joined: 06 Aug 2009 Posts: 402 | TRs | Pics
|
|
hbb
Member
|
Tue Jul 09, 2019 2:19 pm
|
|
|
To locate a position in the UTM system, the first thing you need to know is which one of the 60 longitudinal zones the position is in. Absent that information, you are dead in the water. So, right from the get-go, you have to start with an east-west "coordinate." The whole system keys off of that, those longitudinal zones are the primary reference point. It doesn't make sense to start with a north-south reference, because that could be in any one of the 60 zones.
I guess the reason that the system starts with longitudinal zones (as opposed to latitude bands) is that you want to carve out the ends of the zones to minimize distortion, like UTM does (the system only covers 84*N to 80*S). If you started with a latitude-based zone, the carve out wouldn't be over the poles as it is in UTM, it would be in the middle of the Atlantic ocean or something along those lines. Separating out the poles is pretty easy, because you can set the zones so they don't "cut off" part of a continent, or end up in the middle of some important shipping route.
|
Back to top |
|
|
Navy salad Member
Joined: 09 Sep 2008 Posts: 1864 | TRs | Pics Location: Woodinville |
hbb wrote: | To locate a position in the UTM system, the first thing you need to know is which one of the 60 longitudinal zones the position is in. Absent that information, you are dead in the water. So, right from the get-go, you have to start with an east-west "coordinate." The whole system keys off of that, those longitudinal zones are the primary reference point. It doesn't make sense to start with a north-south reference, because that could be in any one of the 60 zones. |
Ahh, that makes perfect sense! I also found the comments about how the established convention for mathematical charts in general is to identify the "X" coordinate along the horizontal axis first, then the "Y" coordinate along the vertical axis logical -- to the point where it seems the "latitude first, longitude second" system is the one that's backwards!
Thanks for the comments!
|
Back to top |
|
|
|