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I need to know the distance in feet between the coordinates N34-00.000 and N34-00.001 (Degrees, minutes and thousanths of minutes) I computed approx 6 feet but am not confidant in my math skills.

SS_Rebelious
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Sarah Good
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  • Welcome to gis.SE. Your question needs more detail to be answerable. In particular, you need to specify whether you want distance "across the ground" or "straight line" (may not make much difference at this scale, but will make a bigger difference as the numbers increase), and at what altitude. As a hint, 1 minute of latitude is roughly 1852 metres (1 nautical mile), so 0.001 of that is 1.8 metres, and I leave it to you to convert into something non-standard like feet. – BradHards Oct 22 '13 at 20:55
  • Thanks and AWESOME! My math wasn't as aweful as I feared.. 1.8m = 5.9 feet. To amplify on the question I guess I am looking for the distance across the ground at Sea level (0 MSL). I assume it gets bigger as altitude increases (but that is really just a total guess)? Is that correct? and if so then I would also want the distance between the two points at 10,000'MSL. – Sarah Good Oct 22 '13 at 21:04
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    Might you post the math you used to get your answer? Using a spheroidal model of the earth with R= 6371000m, you should get a distance of 6.08021252430877' (assuming same longtitude). – Paul Oct 22 '13 at 21:09
  • If you are asking me... I just used an online calculator that said 1 meter = 3.28084, and plugged in the 1.8 meters that BradHards above figured out. For my purposes + or - even a foot is accurate enough. But if your question is to him, it was asked with regard to Latitude, not Longtitude so maybe that is the difference? – Sarah Good Oct 22 '13 at 21:15
  • To add extra detail into your question it is best to edit it - that gives you much better formatting options than Comments. – PolyGeo Oct 22 '13 at 21:17
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    It'll just be arc length with greater radius. 10kft is noise on the scale of the earth, so it'll be approximately the same. – BradHards Oct 22 '13 at 21:17
  • @SarahGood, my question was directed to you. I'm curious how you initially computed "approx 6 feet" and was asking if your math was right; we can tell you if it's correct if you post what you did. – Paul Oct 22 '13 at 21:20
  • This is a faq: you can find a few hundred posts dealing with this issue. :-) – whuber Oct 22 '13 at 21:53
  • @ Paul, I knew the distance between lines of Lat were approx. 60NM and that meant each minute of Lat was approx. 1 NM and 1NM is approx. 6080 feet, so moving the decimal over to determine what .001 of a minute was gave me 6 feet. I am a C-130 nav for the USAF and needed to get a rough wag with regard to how much error a crewmember is causing in the navigation system when they fat finger the coordinates. – Sarah Good Oct 23 '13 at 13:45
  • @ BradHards... Thanks for clarifying that 0K and 10K is "noise" when compared to the scale of the earth. Thanks! – Sarah Good Oct 23 '13 at 13:47

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I created points in a feature class using the WGS84 datum (geographic coordinate system) on the prime meridian (0° longitude) at these two latitudes, and then measured the geodesic distance between them in ArcMap. The geodesic distance computed by ArcMap is 6.065419 Feet.

JustInTheWoods
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