How does the UTM # work?

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acurayyz

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When an EMS unit is given a call they are told an address, cross street(s), sometimes a map page/number, and then UTM. What does the UTM (universal transverse mercator) number give them? It is normally just a 6-7 digit number. Is it meant to be entered on their computer system or is it a physical map? I can understand how a map page would correspond to a part of a mapbook showing the street but where does the UTM number fit in?
 

exkalibur

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It's used to reference parts of a map.

Think of it in roughly the same terms as latitude and longitude (although they're very different).

A better analogue would be this...when you look up a street in a regular map, it'll say page 35, B6. You go to page 35, look up row B and column 6.

If a call is page 8839, UTM 646-4776...it'll mean go to page 8839, look up row 646 and column 4776.

That's a very rough way of doing it, but this ensures that every location in the Province (and in theory, the world) has a unique location. The entire Province of Ontario is chopped up into map pages so no two pages will be the same anywhere in Ontario, nor will the UTM.
 

bpsmicro

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The UTM sub-set that MOH uses defines a 1km block. A "full" UTM, as you might see on a GPS, would have more digits, and also have a map designation. In Eastern Ontario, that's usually 18T. So often the CACC-issued UTM requires a bit more local knowledge to decode.
For the actual crews, their computers are set at start of shift to their general area of interest, so the map number is preset.

As an example, Parliament Hill is at (approximately) 45.4237 by -75.7004. That translates to UTM "18T 445206E 5030266N", which may be expressed as "18T4452065030266". That gets you to a 1m resolution.

The software used by MOH only takes the digits required for a 1km resolution, so in this example "18T 445E 5030N", or "4455030".

A while back, I took a sample javascript web page from Javascript Calculators and modified to a smaller and somewhat simpler version that lets me plug in the CACC-supplied UTM and pop up Google Maps in the defined area. Because of the 1km resolution, the actual location is somewhere in that vicinity.
If anybody's interested, you can grab what I have at UTM interface to Google maps
I'd recommend doing a SaveAs to your local machine, then bookmark your local copy. If you want to set a different default map (mine's set as 18T), you can edit your local copy.

Brad.
 

bosco836

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Although a bit off topic:

How does the CACC decided weather to give a UTM code or a GEO Code?

I notice that with Windsor CACC, either one or the other is given on most dispatches.
 

acurayyz

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The UTM sub-set that MOH uses defines a 1km block. A "full" UTM, as you might see on a GPS, would have more digits, and also have a map designation. In Eastern Ontario, that's usually 18T. So often the CACC-issued UTM requires a bit more local knowledge to decode.
For the actual crews, their computers are set at start of shift to their general area of interest, so the map number is preset.

As an example, Parliament Hill is at (approximately) 45.4237 by -75.7004. That translates to UTM "18T 445206E 5030266N", which may be expressed as "18T4452065030266". That gets you to a 1m resolution.

The software used by MOH only takes the digits required for a 1km resolution, so in this example "18T 445E 5030N", or "4455030".

A while back, I took a sample javascript web page from Javascript Calculators and modified to a smaller and somewhat simpler version that lets me plug in the CACC-supplied UTM and pop up Google Maps in the defined area. Because of the 1km resolution, the actual location is somewhere in that vicinity.
If anybody's interested, you can grab what I have at UTM interface to Google maps
I'd recommend doing a SaveAs to your local machine, then bookmark your local copy. If you want to set a different default map (mine's set as 18T), you can edit your local copy.

Brad.
Cool app but the UTM numbers I am getting do not correspond in location to the actual address of the call. Is it possible that they are not using "18T"? I am listening to a feed that includes York, Durham, and Peel EMS.
 

kayn1n32008

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Cool app but the UTM numbers I am getting do not correspond in location to the actual address of the call. Is it possible that they are not using "18T"? I am listening to a feed that includes York, Durham, and Peel EMS.
You need to know the correct UTM zone that you are interested in. There are a few ways to figure it out, probably the easiest is to ask a legal land surveyor what zone(s) the area you listen to is in. Another is to get a hold of a GPS/GNSS reciever and determin your location in UTM format. Also make sure you have the correct map datum, there is a big difference between NAD 27 and NAD83 coordinates. Most likely they are using NAD 83 coordinates.

Edit: If I remember my geography it looks like you are probably in zone 17T.
 
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kayn1n32008

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As an example, Parliament Hill is at (approximately) 45.4237 by -75.7004. That translates to UTM "18T 445206E 5030266N", which may be expressed as "18T4452065030266". That gets you to a 1m resolution.

The software used by MOH only takes the digits required for a 1km resolution, so in this example "18T 445E 5030N", or "4455030".

Brad.
Does the dispatcher give the Northing before the Easting or vice versa? As a surveyor we almost always give Northing before Easting unless we are entering coordinates into a handheld Garmin.
 

bpsmicro

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I've never heard UTM being done in any way other than Easting then Northing.

@bosco836: MOH "rules" say they're supposed to always give *both* UTM and the MOH map book reference (which I assume is what you mean by "GeoCode"). But I suppose there may be some practical reason why one or the other may not be appropriate, or in some cases their computer system won't give them one or the other (especially if the supplied address doesn't validate).

@acurayyz: There are probably better maps, but if you look at DMAP: UTM Grid Zones of the World it may help narrow down the possible zone you want.

Brad.
 

kayn1n32008

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I've never heard UTM being done in any way other than Easting then Northing.

Brad.
It must be a surveyor thing then, both hiway and oilpatch work, have always given Norhing before Easting. The only exception is if we are entering coorinates into a Garmin. If entering coordnates into a totalstation, or survey grade GNSS it is always Northing, Easting, Elevation... Learned something new today.
 

gregandkyra

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The UTM that is provided to EMS is provided from the dispatching system automatically once a address is entered into the system. The paramedic can then enter the UTM into their mapping computer AKA Locator computer in the ambulance. Some CACCs only provide the map page if it is an out of town ambulance or their Locator computer is not working depending on local policies. The map page/UTM can be used to locate the general area in back-up map books in the ambulances.
 
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The UTM to Google Maps app works great, as long as you use the correct UTM Zone.

But what map book do they use? Is it an "off the shelf" product that we can buy?
Or is it something "special" that only they have access to?
 

gregandkyra

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Map books are provided by the Ministry of Health. Generally they are used as back up now that computers are in the ambulances. Also the mapping system is standard across Ontario.
 
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