How far does the last digit equate to?

[+bootsycat]

I am new to geocaching and have a garmin etrex h. Can anyone tell me how far on the ground the last of the digits on the reading would be - eg what would be the difference in feet or metres between N 51° 31.214 and N 51° 31.213?

 

Many thanks

[daveindeal]

around 6 feet

 

when ever working out new caches i use this to see if its in the .1 mile rule but shows you right down to the feet how far

 

Coordinate Distance Calculator

[+Gitchee-Gummee]

Depends upon latitude. Greater at/near equator, less north or south of equator.

 

Add to that, the earth isn't exactly round.

[+StarBrand]

Markwell has a nice answer to this common question:

 

http://www.markwell.us/geofaq.htm#Feet

 

or

 

http://support.Groundspeak.com//index.php?...page&id=210

[+Titus1919]

If I remember right 1 degree is 60 nautical miles so 1 minute = 1 nautical mile so the last digit is .001 of a nautical mile. a nautical mile is 2000 Yards. So that would be 2 Yards or 6FT. (1.8288000000000002 Meters)of course you have to be using the DD'MM.MMM

[+Cardinal Red]

If I remember right 1 degree is 60 nautical miles so 1 minute = 1 nautical mile so the last digit is .001 of a nautical mile. a nautical mile is 2000 Yards. So that would be 2 Yards or 6FT. (1.8288000000000002 Meters)of course you have to be using the DD'MM.MMM

But that only works for .001 Minute Latitude. Longitude starts at your 6 feet for .001 Minute ONLY AT THE EQUATOR.

It narrows to zero (touching) at the Poles. A good rough guide for Longitude spacing is 6 feet times the Cosine of Latitude.

 

Longitude spacing at 0 Degrees Latitude (Equator) - Cosine 0 = 1

1 times 6 = 6 feet per .001 Minute

 

Longitude spacing at 60 Degrees Latitude (Equator) - Cosine 60 = .5

.5 times 6 = 3 feet per .001 Minute

 

Longitude spacing at 90 Degrees Latitude (Pole) - Cosine 90 = 0

0 times 6 = 0 feet per .001 Minute

[+Titus1919]

If I remember right 1 degree is 60 nautical miles so 1 minute = 1 nautical mile so the last digit is .001 of a nautical mile. a nautical mile is 2000 Yards. So that would be 2 Yards or 6FT. (1.8288000000000002 Meters)of course you have to be using the DD'MM.MMM

But that only works for .001 Minute Latitude. Longitude starts at your 6 feet for .001 Minute ONLY AT THE EQUATOR.

It narrows to zero (touching) at the Poles. A good rough guide for Longitude spacing is 6 feet times the Cosine of Latitude.

 

Longitude spacing at 0 Degrees Latitude (Equator) - Cosine 0 = 1

1 times 6 = 6 feet per .001 Minute

 

Longitude spacing at 60 Degrees Latitude (Equator) - Cosine 60 = .5

.5 times 6 = 3 feet per .001 Minute

 

Longitude spacing at 90 Degrees Latitude (Pole) - Cosine 90 = 0

0 times 6 = 0 feet per .001 Minute

 

You are 100% right on that.

[+WhoDis]

Depends upon latitude. Greater at/near equator, less north or south of equator.

 

Add to that, the earth isn't exactly round.

The earth's round? What? When that happen?

[+Gitchee-Gummee]

Depends upon latitude. Greater at/near equator, less north or south of equator.

 

Add to that, the earth isn't exactly round.

The earth's round? What? When that happen?

Not only that, but it is tilted, to boot!

[+bootsycat]

Thanks to all for your replies - I'm not going to attempt to understand the round/tilt differences, but "about 6ft" is good enough for me!

[+ras_oscar]

6 foot longitute 4 foot latitude, reducing as you get further from the poles.

 

And you thought it was a simple question !!!

[GermanSailor]

eg what would be the difference in feet or metres between N 51° 31.214 and N 51° 31.213?

1.852 Meters.

 

1 minute of arc along a great circle equals 1852 meters (1 nautical mile). The third digit after the decimal is 1.852 meters.

 

This is why distances on nautical charts are always measured between parallels with the dividers.

 

GermanSailor

[+J the Goat]

About 72 nano's end to end.

[+dfx]

About 72 nano's end to end.

how many .50 ammo cans does that equal?

[7rxc]

About 72 nano's end to end.

how many .50 ammo cans does that equal?

 

That would depend... .50 cal boxes are fairly standard size... nanos can cover a lot of ground... being simply small micros... of course you might also consider volume as well, but the discussion is length, so the long axis measurement is it.

 

Guess we wait for J T G to measure his nano.

 

Doug

[+ventura_kids]

I am new to geocaching and have a garmin etrex h. Can anyone tell me how far on the ground the last of the digits on the reading would be - eg what would be the difference in feet or metres between N 51° 31.214 and N 51° 31.213?

 

Many thanks

 

don't forget to check the accuracy too.

You're gonna get more error from that than the 6 foot minimum (near the equator).

Around our place, we never get closer than about 11 foot accuracy.

 

So we search in an 11 + 6 = 17 Radius

[+Team Cotati]

Since most every gpsr these days have that handy compass rose with the pointer that points to the cache coords and gives the distance thereto, when searching for a geocache, that last digit is, for all practical purposes, meaningless.

 

We sometimes use it if having trouble finding the cache but then only when we are very close but then only as a sort of cross check against the pointer.

 

We met a fellow cacher one day who had found over 100 caches using only those coord numbers. He'd actually gotten fairly good at following the lat/lon lines, then someone showed him the arrow thingie and then it was like....duhhh. I am fairly certain that he uses the arrow thingie a whole lot more ever since the revelation!

 

Too funny.

Edited April 11, 2010 by Team Cotati

[+Chrysalides]

Since most every gpsr these days have that handy compass rose with the pointer that points to the cache coords and gives the distance thereto, when searching for a geocache, that last digit is, for all practical purposes, meaningless.

I've used a Nuvi occasionally, when I left both handhelds at home (shocking, I know) and had to navigate watching the lat / lon numbers on the satellite screen. Before I got my handhelds, I would write the decimal minutes on a tiny post-it and stick it to the bezel of the Nuvi. That got tiring really fast.