Meridian GPS & UTM

Submitted: Tuesday, Feb 22, 2005 at 12:44
ThreadID: 20661 Views:5210 Replies:6 FollowUps:11
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I've got a Meridian GPS which I have always used in Lat and Long format. I tried putting in some UTM co-ordinates I was given and have encountered a problem. The coordinates were six digits (723910) I can't get my GPS to accept this coordinate. It seems to want be in the format 54 2749**E 61151**N (my home co-ords with some digits hidden). Help please.
I've trolled the web and the 6 digit number seems to be a common abbreviation for waypoints but how do I get it into my unit.
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Reply By: Shawn - Tuesday, Feb 22, 2005 at 12:52

Tuesday, Feb 22, 2005 at 12:52
They are a 6 figure grid references (accurate to 100m)

Go into setup and change the grid coordinate setup from Lat/long to MGS. This is Military Grid Reference and you can infup it to accept 6 or 8 fig grids (giving you accuracy down to 10m)

Cheers
Shawn
AnswerID: 99487

Follow Up By: Patrolman Pat - Tuesday, Feb 22, 2005 at 13:06

Tuesday, Feb 22, 2005 at 13:06
Thanks for the quick response, thats seems to have helped. Next Q, when I set up in MGRS it asks for grid type MGRS -1, MGRS-2 or MGRS-3. Which one.
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Follow Up By: Shawn - Tuesday, Feb 22, 2005 at 14:29

Tuesday, Feb 22, 2005 at 14:29
Pat,
I use MGRS-1 on mine and it works fine.
I don't really know what the differences are between MGRS-1,2,3
As stated below you have to know what map the coordinates are refering to, or they may be prefixed with the world area coordinates:
eg: 56H LH 123456

Cheers
Shawn
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Reply By: Mad Dog (Victoria) - Tuesday, Feb 22, 2005 at 13:49

Tuesday, Feb 22, 2005 at 13:49
Pat those numbers are metres from a reference point. To be of any use you must know the zone they relate to or have the same map they were plucked from.
In the case of your home UTM 54 is the zone

Have a look here for the world zones

http://www.dmap.co.uk/utmworld.htm
AnswerID: 99488

Follow Up By: Mad Dog (Victoria) - Tuesday, Feb 22, 2005 at 14:07

Tuesday, Feb 22, 2005 at 14:07
Pat, you'll see from that map that zones have a letter as well. If you know roughly what part of the world the coordinates you were given relate to you can figure out the zone and enter the full coordinates into your gps
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Reply By: The Explorer - Tuesday, Feb 22, 2005 at 18:11

Tuesday, Feb 22, 2005 at 18:11
Pat – as mentioned in previous replies, the numbers you have are not coordinates as such but part of a Grid Reference (the system is known as the Universal Grid system – methods on their use and application are generally provided on topographical maps). You have only been supplied with part of the information required to identify the location – information that should also be supplied includes the actual map name and number, the Zone and related 100 000m grid square.

The numbers you have could refer to a number of places as the grid reference is the coordinates cut down – the first three are part of the easting and the second three are part of the northing. For example from a map I have the UGC for 379300mE and 6302100mN is 793021….but if I don’t give you the other information you will not be able to make use of the data as you could only guess the other required numbers. Only if you know the map they were from you could work out which area was being referred to.

The system is not usually used when providing information to a GPS user but to a Map user .i.e the person supplying the information would be under the assumption that you have a copy of the relevant map in your hand.

Cheers
Greg
I sent one final shout after him to stick to the track, to which he replied “All right,” That was the last ever seen of Gibson - E Giles 23 April 1874

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Reply By: Member - Rick (S.A.) - Tuesday, Feb 22, 2005 at 18:12

Tuesday, Feb 22, 2005 at 18:12
Pat ,

If you get hold of a topo map, it will give you the UTM coordinate details. In other words, there is a little section that tells you how to establish in UTM language , where you are. That has the relevant info that you should be able to punch into the GPS
eg 53 H 123456E 123456N.

I dunno if your model PPS wants more than six digits. Mine ( a Garmin does).

by the way, were you driving north along Portrush Rd on Monday am. Saw a white GU, raised, ladders on the r/rack & EO wheel cover. Yes??

Cheers
AnswerID: 99519

Follow Up By: Patrolman Pat - Tuesday, Feb 22, 2005 at 18:28

Tuesday, Feb 22, 2005 at 18:28
Well spotted Rick, that was me.

My GPS wants numbers as you describe, the reference (6 digit) I was given was from someone who shall remain nameless (OK it was Pesty ; )) ). He took them direct from his GPS. I'll compare notes with him next time I see him and I'm sure we can work it out from there.

I did arrive at the destination as Pesty's written directions were spot on :)

Once I've worked this out I've got ot get to grips with OziExpolrer. Phew.
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Follow Up By: Member - Pesty (SA) - Tuesday, Feb 22, 2005 at 19:49

Tuesday, Feb 22, 2005 at 19:49
Hi Pat,
Yes I didnt give you enough info to punch into your GPS, but enough to check your location with the written position when you pulled up, if your GPS was set on utm.
Sorry mate to put you through such a difficult time hahahah, next time I will give you the full gammit.
The MGRS ( military grid reference system) is slightly different to the UTM/UPS system, so set your GPS to Datum WGS 84 and the Nav system to UTM/UPS

Cheers
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Follow Up By: Patrolman Pat - Tuesday, Feb 22, 2005 at 20:36

Tuesday, Feb 22, 2005 at 20:36
My GPS was on the desk at home so not much use last weekend anyway LOL. I was having a play when I got home to compare UTM and Lat/Long, it's a good job Alex has joined the Joey scouts, he can navigate across the Simpson for me.
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Follow Up By: The Explorer - Wednesday, Feb 23, 2005 at 00:27

Wednesday, Feb 23, 2005 at 00:27
Hello gentleman - in my never ending quest to learn all about GPS use mapping etc I am very intrested to know why you use this system of recording positions. I can see it being handy in making quick reference to general positions...but what other advantage over giving full UTM or Lat/Long coordinates (just a few more numbers) would it have? It seems to remove the accuracy now availalble with handheld GPS units (~5m) by rounding numbers to the nearest 100m - Ok for a lot of applications I suppose but the format is a bit confusing for users (new and old - as illustrated in posts). I have come across its use in a few Govt publications and it is annoying in is inaccuracy eg bore hole locations. I have a funny feeling it is an outdated system made almost redundant when GPS units were invented
Cheers
Greg
I sent one final shout after him to stick to the track, to which he replied “All right,” That was the last ever seen of Gibson - E Giles 23 April 1874

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Follow Up By: Mad Dog (Victoria) - Wednesday, Feb 23, 2005 at 09:01

Wednesday, Feb 23, 2005 at 09:01
Greg, the accuracy is 1 metre. When that accuracy is not required the coordinates can be abbreviated.

I copied this from http://www.maptools.com/UsingUTM/UTMdetails.html
Some other good stuff about UTM on that site as well.
-----------------
The Universal Transverse Mercator projection and grid system was adopted by the U.S. Army in 1947 for designating rectangular coordinates on large scale military maps. UTM is currently used by the United States and NATO armed forces. With the advent of inexpensive GPS receivers, many other map users are adopting the UTM grid system for coordinates that are simpler to use than latitude and longitude.

The UTM system divides the earth into 60 zones each 6 degrees of longitude wide. These zones define the reference point for UTM grid coordinates within the zone. UTM zones extend from a latitude of 80° S to 84° N. In the polar regions the Universal Polar Stereographic (UPS) grid system is used.

UTM zones are numbered 1 through 60, starting at the international date line, longitude 180°, and proceeding east. Zone 1 extends from 180° W to 174° W and is centered on 177° W.

Each zone is divided into horizontal bands spanning 8 degrees of latitude. These bands are lettered, south to north, beginning at 80° S with the letter C and ending with the letter X at 84° N. The letters I and O are skipped to avoid confusion with the numbers one and zero. The band lettered X spans 12° of latitude.

A square grid is superimposed on each zone. It's aligned so that vertical grid lines are parallel to the center of the zone, called the central meridian.

UTM grid coordinates are expressed as a distance in meters to the east, referred to as the "easting", and a distance in meters to the north, referred to as the "northing".
--------------------

Personally I find it an easier system to use. Being metres the numbers are something I can relate to, degrees, minutes and seconds don't mean much to me.
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Follow Up By: The Explorer - Wednesday, Feb 23, 2005 at 10:04

Wednesday, Feb 23, 2005 at 10:04
Madog – unfortunately handheld GPS units do not have a guaranteed accuracy of 1 metre so even though the coordinates given are to the nearest 1m don’t assume that’s exactly where you are – While you may possibly be at that position you could be 2, 3 or 4 metres away (or more) in any direction. I understand that if accuracy is not needed then its no big deal to use the universal grid reference instead of full UTM coords – or even to round the UTM numbers to the nearest 100m - just was curious as to why you would bother given the confusion it obviously creates. You must also assume that when giving the data out in this format that the person receiving it is happy with the inaccuracy.

Not sure what this has got to do with UTM ie why you posted the info - we have been talking about the Universal Grid Reference System (the abbreviation of coords) not Universal Transverse Mercator - well I thought that was what we were talking about based on first post. I also use UTM all the time (every working day + most weekends) for the same reasons as you.

Cheers
Greg
I sent one final shout after him to stick to the track, to which he replied “All right,” That was the last ever seen of Gibson - E Giles 23 April 1874

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Follow Up By: Mad Dog (Victoria) - Wednesday, Feb 23, 2005 at 12:37

Wednesday, Feb 23, 2005 at 12:37
Sorry Greg, I posted the info because the first post was based on the fact that Pesty had dropped the zone info from the UTM coordinates and Pat's GPS wouldn't accept the coordinates. I therefore assumed you were unfamilar with UTM...my apologies but hopefully some else will pick the system up. From what I can gather the universal grid reference you refer to is simply UTM with truncated accuracy, is that correct ? Not sure why anyone would bother with that either.
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Reply By: R.E.P.C.O. - Wednesday, Feb 23, 2005 at 10:06

Wednesday, Feb 23, 2005 at 10:06
MGRS is NOT UTM MGRS is a system designed by the goddam yankee army.
If you set your GPS to MGRS you will not get the correct location. MGRS is not used, never has been used and will not be used in Australia.

UTM has an Easting of 6 numbers and a Northing of 7 numbers
Your GPS settings should say something like UTM UPS
Once you enter in the UTM coordinates the GPS should pick the correct Zone.
The Zone will read something like 55H
You will see UTM coordinates that are only 4 and 3 numbers. This then requires you add three zeroes to make the 6 and 7 digit numbers.

UTM is the best and easiest method and the most accurate for the average person.
All the new land based maps in Australia are printed now generally with UTM and DMS printed lightly. We only use UTM now for all work.
AnswerID: 99642

Follow Up By: Shawn - Thursday, Feb 24, 2005 at 08:12

Thursday, Feb 24, 2005 at 08:12
REPCO,
Just curious as to why you say that MGRS system will never be used in Australia.
This system can give you accuracy to 1m on thr ground with a ten fig grid.
Years ago the system was only good for the US military because of the inbuilt error, but it has now been turned off. I know it can all turn to poo if they decide to flick the switch and turn the error back on.
Is this the reason why you say it will never be used in Aus??
Cheers
Shawn
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FollowupID: 358117

Reply By: Patrolman Pat - Wednesday, Feb 23, 2005 at 15:18

Wednesday, Feb 23, 2005 at 15:18
Thanks to all who took the time to reply. The more I read and play with the GPS the more I learn. Might even find my way to the fridge for another beer now ;)
AnswerID: 99708

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