# Utm Vs Lat/long

## Recommended Posts

Do you think UTM is more accurate than lat/Long?

Do you think UTM is more accurate than lat/Long?

I don't know if it is more accurate or not. It is what I use because that is what I was taught to use in the Army as a Forward Observer. We needed to be pretty accurate when giving coordinates to the big guns.

More accurate ? In what regard? But basically, no. Unless you are on the center line of a zone, North and South are distorted. There are problems projecting across zones. Too far north or south? There are problems. If you want to make the world a simpler place to go from one place to another, sometimes it is easier. Using it with some maps are easier. It makes most points on the map easy understandable predictable meters apart. It attempts to make what is somewhat mostly round, flat.

Opinions are like belly buttons......in that everybody's got one....

Here's mine....

When you are trying to find something / someplace, there is a distance involved between where you are and "it", and your brain has to be able to interpret that distance from some data describing it.

(Most) people's brains do not "think/work" in DMS, or decimal degrees, etc. as related to distance, so there is a constant mental attempt to convert to some understandable "distance".

Since UTM is based on a 1000 meter grid and only uses two "directions", Easting and Northing, its always easy to understand whether you need to go "More East" or Less East" , or "More North" or "Less North". Considering that the last three numbers in each of the UTM coordinates tell you where the point is within that particular 1000 meter square, you can quickly visualize which direction, and how far, you need to go. Whether or not you are familiar with the metric system, you can just equate each of those last three numbers to a "pace" or "step".

If you are working with a paper map with UTM coordinates, the 1000 meter squares are usually described in the "collar" or border area. USGS quads use "little blue" numbers and tick marks.

More accurate??, probably open to lots of debate.....but once you get familiar with using UTM , it sure does "Fit in the Brain" as being a lot more logical .

I think I will stick to Lat/Long

Opinions are like belly buttons......in that everybody's got one....

Here's mine....

When you are trying to find something / someplace, there is a distance involved between where you are and "it", and your brain has to be able to interpret that distance from some data describing it.

(Most) people's brains do not "think/work" in DMS, or decimal degrees, etc. as related to distance, so there is a constant mental attempt to convert to some understandable "distance".

Since UTM is based on a 1000 meter grid and only uses two "directions", Easting and Northing, its always easy to understand whether you need to go "More East" or Less East" , or "More North" or "Less North". Considering that the last three numbers in each of the UTM coordinates tell you where the point is within that particular 1000 meter square, you can quickly visualize which direction, and how far, you need to go. Whether or not you are familiar with the metric system, you can just equate each of those last three numbers to a "pace" or "step".

If you are working with a paper map with UTM coordinates, the 1000 meter squares are usually described in the "collar" or border area. USGS quads use "little blue" numbers and tick marks.

More accurate??, probably open to lots of debate.....but once you get familiar with using UTM , it sure does "Fit in the Brain" as being a lot more logical .

Opinions are like belly buttons......in that everybody's got one....

Here's mine....

When you are trying to find something / someplace, there is a distance involved between where you are and "it", and your brain has to be able to interpret that distance from some data describing it.

(Most) people's brains do not "think/work" in DMS, or decimal degrees, etc. as related to distance, so there is a constant mental attempt to convert to some understandable "distance".

Since UTM is based on a 1000 meter grid and only uses two "directions", Easting and Northing, its always easy to understand whether you need to go "More East" or Less East" , or "More North" or "Less North". Considering that the last three numbers in each of the UTM coordinates tell you where the point is within that particular 1000 meter square, you can quickly visualize which direction, and how far, you need to go. Whether or not you are familiar with the metric system, you can just equate each of those last three numbers to a "pace" or "step".

If you are working with a paper map with UTM coordinates, the 1000 meter squares are usually described in the "collar" or border area. USGS quads use "little blue" numbers and tick marks.

More accurate??, probably open to lots of debate.....but once you get familiar with using UTM , it sure does "Fit in the Brain" as being a lot more logical .

Opinions are like belly buttons......in that everybody's got one....

Here's mine....

When you are trying to find something / someplace, there is a distance involved between where you are and "it", and your brain has to be able to interpret that distance from some data describing it.

(Most) people's brains do not "think/work" in DMS, or decimal degrees, etc. as related to distance, so there is a constant mental attempt to convert to some understandable "distance".

Since UTM is based on a 1000 meter grid and only uses two "directions", Easting and Northing, its always easy to understand whether you need to go "More East" or Less East" , or "More North" or "Less North". Considering that the last three numbers in each of the UTM coordinates tell you where the point is within that particular 1000 meter square, you can quickly visualize which direction, and how far, you need to go. Whether or not you are familiar with the metric system, you can just equate each of those last three numbers to a "pace" or "step".

If you are working with a paper map with UTM coordinates, the 1000 meter squares are usually described in the "collar" or border area. USGS quads use "little blue" numbers and tick marks.

More accurate??, probably open to lots of debate.....but once you get familiar with using UTM , it sure does "Fit in the Brain" as being a lot more logical .

To-day my GPSr showed me D decimal xx.888 xxx. 667 when the needle started twitching fore and aft, which means I'm getting close. I was looking for xx.882 xxx.662 But I've been trained in UTM, so I had little idea as to which way to go or how far. Obviously not hundreds of meters but in deep stuff it does make a difference. With UTM you only have to glance at the sun or whatever to get a sense of direction ENSW. So my advice is - stick with what you can visualise. If its LAT/LONG fine.

Edited by La Perouse

LL is more accurate than UTM by design.

However if you ever have to do math using coordinates UTM is far and away easier. Because it's easier you are less likely to make mistakes.

For most purposes UTM and LL are "close enough".

If you are using your GPS by itself, then it doesn't make one whit of difference which you are using.

BUT...If you are using your GPS with a map, and pulling coordinates off the map for input into your GPS, or putting coordinates from your GPS onto the map, then UTM is by far easier to learn easier to use, and much more user friendly all the way around.

UTM is allot easier to use. As fare as one being more accurate. Well, you won't notice the differance on a civilian GPS. Generally speaking I've used the MGRS in the military which is based off UTM. If you are using your GPS in conjunction with maps, in my opion it's a no brainer UTM all the way. Heck most people (90%) don't even know how to use a map: sectioning, resectioning, Azimuth, back Azimuth, Gm Angle..etc. Land NAV UTM is the BEST.

Edited by bco2135

One thing that I have long puzzled over in here: It seems to me that the majority of "users, service providers, long/lat conversion services, mapping services" and the like use degree decimal notation for the display of long/lat. The geocaching.com cache pages use minute decimal. Does anyone know the reasoning behind this? Is there some particular benefit to the method chosen? What would the negatives be if the cache listings used degree decimal as opposed to minute decimal?

Edited by Team Cotati

...What would the negatives be if the cache listings used degree decimal as opposed to minute decimal?

There would be no negatives. If anything it would simplify the math a bit on some caches.

Using DDD.DDDD (however many decimals you need) would still need to be convirted to DD MM SS.SS or DDD MM.MMM every now and then but we face that no matter which variation you pick.

If you start with UTM, you End with UTM..... no conversion.....real simple.

It's when you use Lat/Lon with all the variations of DMS or decimal degrees, or decimal minutes ,etc etc, that all the (unnecessary) conversion enters the picture.

The puzzlement and various questions in other posts about conversions seem to answer the OP question in this thread.

The geocaching.com cache pages use minute decimal. Does anyone know the reasoning behind this? Is there some particular benefit to the method chosen? What would the negatives be if the cache listings used degree decimal as opposed to minute decimal?

Most GPS receivers use degrees/minutes as their default mode when new, presumably because that's the common marine usage (1 minute of latitude = 1 nautical mile).

I'd expect to have even more confusion among newcomers with either of the other formats.

And the confusion REALLY sets in if someone asks "How much distance on the ground does 1 Minute equal?" , and since locations are not one dimensional, you have to include Longitude.

And the confusion REALLY sets in if someone asks "How much distance on the ground does 1 Minute equal?" , and since locations are not one dimensional, you have to include Longitude.

Actually, it's Latitude you would have to provide so I could tell you what YOUR Longitude spacing is.

The geocaching.com cache pages use minute decimal. Does anyone know the reasoning behind this? Is there some particular benefit to the method chosen? What would the negatives be if the cache listings used degree decimal as opposed to minute decimal?

Most GPS receivers use degrees/minutes as their default mode when new, presumably because that's the common marine usage (1 minute of latitude = 1 nautical mile).

I'd expect to have even more confusion among newcomers with either of the other formats.

I didn't realize that my questions indicated a particular concern wrt 'newcomers' being confused. If they did then that was a mistake on my part.

I agree with most of the posts that when working with maps (i.e. Topo Maps) and when working in small areas (e.g. geocaching), UTM is the way to go. When working on a more global scale, however, I still find Lat/Long easier; for example is someone told me they were at 10U E 485386 N 5453942 I wouldn't have a clue where on the globe they would be, but if they said they were at 49 deg, 14 min North and 123 deg, 12 West, I could roughly figure out where on the globe that was.

Btw, I agree with a previous post, that I prefer Lat/Long in decimal degrees as opposed to deg/min or deg/min/sec, but I find most topo maps use deg min.

I should have expressed the context. I read in a outdoor photography magazine article about GPS that UTM calculations tend to have a smaller percentage of error because it uses metric. I wanted to know wheither that was true in the real world.

I should have expressed the context. I read in a outdoor photography magazine article about GPS that UTM calculations tend to have a smaller percentage of error because it uses metric. I wanted to know wheither that was true in the real world.

If you want to have a lot of fun, better express it as MMM YYYY F II fractional ! I mean, M for mile, Y for Yards, FF for feet II for inch and than fraction of inch afterwards !!!

When I was hunting in Maine, before the GPS, I was quicker to determine distances etc on 24K topo map using a ruler in cm so 1cm is 240 meters than my friend fumbling with inhces equal aprrox to that many miles or so !

Not to mention the 1/100 000 scale which is standard the world over.

Even heard that the mile used for surveying is not quite the same as the mile derived from the inch (5280 X 12) standardised in 1890 as 25.4mm excactly because before it wasn't exactly 25.4mm !

I think I will stick to Lat/Long

Give UTM a chance. You can find instructions on how to use UTM on the internet. Once you start understanding UTM, I think you'll like it more than lat/long. As far as accurate, my opinion is that they are equally accurate.

I use just a GPS for caching.

Ask yourself what UTM is. O.K., you probably answered that is is merely a projection of Long/Lat. to a 2D system. Long./Lat is more accurate, but unlike longitude, latitude keeps getting squished closer and closer together as you go north or south from the equator. "But I need a coordinate system so I can calculate distances and create designs in an appropriate mathematical format, and plot things with a simple ruler.", you say. "What do I do?", you ask. You project to the best extent your round cap of your theoritical ellipsoid from Long./Lat. to a flat surface like your map, ie. UTM. Metric has nothing to do with accuracy, it is just what was decided in defining UTM coordinates.

"So how do I compensate for the squishing affect as I move north-south, and east-west?", you ask. The designation of UTM changes for to incorporate the corrections, ie. 15,16,17 R,S,T, etc. keeping UTM on a 2D grid.

The geocaching.com cache pages use minute decimal. Does anyone know the reasoning behind this? Is there some particular benefit to the method chosen? What would the negatives be if the cache listings used degree decimal as opposed to minute decimal?

Most GPS receivers use degrees/minutes as their default mode when new.

I'd expect to have even more confusion among newcomers with either of the other formats.

I didn't realize that my questions indicated a particular concern wrt 'newcomers' being confused. If they did then that was a mistake on my part.

You asked for a reason why the geocaching site uses DD MM.mmm format. One reason is that most GPS units use that format when first taken out of the box and it is therefore least likely to be confusing for newcomers who may not even know how to change the setting to any other format.

I don't think you can meaningfully say that LatLong OR UTM are "accurate" ... they are simply measuring systems and artificial ones at that. UTM, though, has a granularity of one meter, you can't measure anything closer than that, LatLong, though, can position a spot to as close as however many decimal places you want to waste.

So, using UTM you can get within one meter of whatever you are describing, with LatLong to however close you want. But what's practical? My GPSr claims 7 foot accuracy occasionally. Do I believe it? No. But even at that claimed accuracy it still can't get me beyond UTM's granularity.

So, what am I saying? Use what works for you when you need it. Luckily the newer (and maye older, I don't know) can convert seamlessly from one to the other, and because the conversion is only as accurate as the current fix, they are EQUALLY accurate.

YMMV

Bill W

## Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

×   Pasted as rich text.   Paste as plain text instead

Only 75 emoji are allowed.