Suggestion: display o-ordinate format alternatives

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kennythe1st
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Suggestion: display o-ordinate format alternatives

Post by kennythe1st » 29 April 10 6:48 pm

I couldn't find a request for this on this forum so maybe I am a lone voice? Anyway I would find the display on a cache page of at least UTM (WGS84) format a great help because I (selfishly) operate in that mode for non-geocaching. I note GC does that so presumably there is some demand.

Yes I know - just another on the looooong list of TTD.

Thanks for the great site =D> , Kenny

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Re: Suggestion: display o-ordinate format alternatives

Post by CraigRat » 29 April 10 7:19 pm

Just looked in to it a bit further,

My brain has exploded as how to do the conversion.

Will see if I can find a simple way...................

Heres HOW, I just need to figure out how it can fit in to our system...............................
http://www.uwgb.edu/dutchs/usefuldata/utmformulas.htm


EDIT: I've found a library, and I'll see what we can do.

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Re: Suggestion: display o-ordinate format alternatives

Post by caughtatwork » 29 April 10 7:23 pm

What's "nu"? (No bad puns please).
Paging SamCarter.

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Re: Suggestion: display o-ordinate format alternatives

Post by SamCarter » 29 April 10 7:37 pm

Races out the door to Scouts much sooner than I was going to ....

Converting base 60 to base 10 is easy.

Converting oblate spheroids (lat-long) to flat squares (UTM) is much much harder. UTM is really cool because it metricises the planet: a change of 1000 in the easting value, for example, is literally 1km. The tricky bit is how to get all these locally flat bits to stick together on a sphere (I think).

Actually I would be happy to try thinking about it, but the truth of the matter is it can't happen for a week or two.

So, for the moment, I've nu idea ...

(Sorry.)

(No, I'm not, really!)

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Re: Suggestion: display o-ordinate format alternatives

Post by caughtatwork » 29 April 10 7:38 pm

I love it when you talk like that :-)

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Re: Suggestion: display o-ordinate format alternatives

Post by CraigRat » 29 April 10 7:40 pm

We've got a doover that'll do the calculation, but we were interested in this part:

Code: Select all

y = northing = K1 + K2p2 + K3p4, where

K1 = Sk0,
K2 = k0 nu sin(lat)cos(lat)/2 = k0 nu sin(2 lat)/4
K3 = [k0 nu sin(lat)cos3(lat)/24][(5 - tan2(lat) + 9e'2cos2(lat) + 4e'4cos4(lat)][
and neither of us knew what 'nu' was :lol:

I should have paid more attention at school :o

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Re: Suggestion: display o-ordinate format alternatives

Post by caughtatwork » 29 April 10 7:54 pm

Hey, I just asked the kid who is in 2nd year Uni and she has no idea either, so it's not just our edumacation.

http://en.wikipedia.org/wiki/Greek_lett ... D_.28Nu.29

None of those look helpful to me. Not quite sure what part neutrinos would play in this.

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Re: Suggestion: display o-ordinate format alternatives

Post by CraigRat » 29 April 10 9:13 pm

kennythe1st wrote:I couldn't find a request for this on this forum so maybe I am a lone voice? Anyway I would find the display on a cache page of at least UTM (WGS84) format a great help because I (selfishly) operate in that mode for non-geocaching. I note GC does that so presumably there is some demand.

Yes I know - just another on the looooong list of TTD.
DONE. Caches listed on GCA now display UTM co-ords on their listing pages.

I'll look in to allowing UTM for HIDING caches later

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Re: Suggestion: display o-ordinate format alternatives

Post by caughtatwork » 29 April 10 9:29 pm

Requested: 29 April 10 5:48 pm
Delivered: 29 April 10 8:13 pm
Elapsed: 2 hours 25 minutes.

All hail the CraigRat =D> =D> =D> =D> =D>

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Re: Suggestion: display o-ordinate format alternatives

Post by rediguana » 29 April 10 9:38 pm

You should be able to use GDAL to transform coords from a massive variety of options. Good open source GIS goodness - all you need to know is the EPSG codes ;)

This would also be scaleable to support other projection/coordinate systems. More importantly, no math skills required!

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Re: Suggestion: display o-ordinate format alternatives

Post by CraigRat » 29 April 10 9:51 pm

caughtatwork wrote:Requested: 29 April 10 5:48 pm
Delivered: 29 April 10 8:13 pm
Elapsed: 2 hours 25 minutes.

All hail the CraigRat =D> =D> =D> =D> =D>
subtract an hour of me wondering what weird people use UTM makes it 1 hour 25 :lol:

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Re: Suggestion: display o-ordinate format alternatives

Post by Papa Bear_Left » 29 April 10 10:24 pm

We used to use UTM all the time in the Good Old Days(tm), i.e. in the days before GPSrs had maps on them.

We noticed that the Sydways street directory had numbers on the grid that were the last few digits of the UTM coords, meaning that we could get the coords of the next waypoint of a multi or a puzzle and find out where it was without going to an Internet cafe or back home to look it up on a mapping website or program.

Given that just following the magic arrow in Sydney usually ends up with you in a cul-de-sac looking at water with no bridge to cross it, this was a major discovery!

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Re: Suggestion: display o-ordinate format alternatives

Post by squalid » 29 April 10 10:25 pm

I got the following from Converting UTM to Latitude and Longitude (Or Vice Versa)

# nu = a/(1-e^2 * sin^2(lat))^(1/2). This is the radius of curvature of the earth perpendicular to the meridian plane. It is also the distance from the point in question to the polar axis, measured perpendicular to the earth's surface.

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Re: Suggestion: display o-ordinate format alternatives

Post by caughtatwork » 29 April 10 10:32 pm

squalid wrote:I got the following from Converting UTM to Latitude and Longitude (Or Vice Versa)

# nu = a/(1-e^2 * sin^2(lat))^(1/2). This is the radius of curvature of the earth perpendicular to the meridian plane. It is also the distance from the point in question to the polar axis, measured perpendicular to the earth's surface.
Oh oh. My brain just fell out.

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Re: Suggestion: display o-ordinate format alternatives

Post by kennythe1st » 30 April 10 6:16 pm

No no no, can't u read? I wanted o-ordinate alternative, not co-ordinate alternative. Like something nu, like not old hat Craig Rat.

Sooo, onto a totally different topic ... it seems the TTDL is even shorter than I, like i maybe? Well I do have some more :idea: :idea: :idea: ... :twisted:

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