<div dir="ltr">Uh so I did the math, and unless I've got this wrong, the difference between survey feet and international feet for tagging, let's say, Mount Everest, is less than seven one-hundredths of an inch. So I'm really not even sure why we're discussing it beyond the fact that we're all nerds about this sort of thing.</div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Sat, Jan 27, 2024 at 8:02 PM Greg Troxel <<a href="mailto:gdt@lexort.com">gdt@lexort.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Minh Nguyen <<a href="mailto:minh@nguyen.cincinnati.oh.us" target="_blank">minh@nguyen.cincinnati.oh.us</a>> writes:<br>
<br>
> This proposal is using the ' symbol instead of the deprecated ft<br>
> symbol, but in practice almost every data consumer understands both<br>
> symbols equally. If someone feels strongly that ft would be less<br>
> error-prone, I'd encourage them to start a new proposal that would<br>
> affect other keys as well.<br>
<br>
I'm ok with that, but I didn't figure it out from the link.<br>
<br>
>> It would be good to explicitly state that in keeping with convention,<br>
>> ft means international feet, perhaps with a parenthetical comment that<br>
>> if someone meant US Survey Feet they would have written ftUS. Maybe<br>
>> this is already documented.<br>
><br>
> As far as I know, no one has ever explicitly tagged a measurement in<br>
> survey feet (as opposed to a survey _on_ feet). As you point out, it's<br>
> a very small difference. I mainly brought it up because I didn't want<br>
> to have to simultaneously propose new unit symbols, which would<br>
> require developer intervention. Some imports have introduced very<br>
> high-precision values, but this is probably not a good practice to<br>
> optimize around.<br>
<br>
Agreed; I just meant to add a parenthetical clarification.<br>
<br>
> You can definitely count me among those whose eyes glaze over whenever<br>
> datums enter the conversation, as they always seem to when discussing<br>
> nationwide imports these days. I'm glad we have folks like you who get<br>
> it.<br>
><br>
> Hopefully it's OK to leave these issues out of the proposal's scope; I<br>
> fear it would quickly sink the proposal because we don't have a very<br>
> good handle on the datums that have already been used all over the<br>
> map. We're only now starting to clean up incorrectly transformed GNIS<br>
> features and TIGER boundaries from, what, 14 years ago, to say nothing<br>
> of more recent imports.<br>
<br>
Yes, I think it's fine. All of those issues apply equally to elevations<br>
in meters, and using feet does not make them any worse or harder<br>
<br>
>> Practically, people type in numbers from a sign, and this sign was<br>
>> probably copied from some earlier sign, and may be in some ancient<br>
>> datum, and may have been erroneous. This proposal has no bearing on<br>
>> that, and that's ok.<br>
><br>
> Yes, I'm very much approaching this key from the perspective of<br>
> documenting what the world says about itself on the ground. More<br>
> mission-critical applications of this elevation data would have their<br>
> work cut out for them...<br>
<br>
Sure, but we should be careful because we do not as lat/lon coordinates<br>
of objects the values chiseled in stone on the store front. We use<br>
measurements and our best guess based imagery, etc. Elevation 100%<br>
should be a similar process of the mapper's best estimate of the true<br>
value. Writing down a sign value is acceptable as an approximation of<br>
that.<br>
<br>
This is entirely different from using a signed name in the name tag.<br>
The the self-labeled name is by definition the right answer. With<br>
elevation, it is not.<br>
<br>
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</blockquote></div>