How many metres is a mintute and second in Log and Lat

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Fargo 1953
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How many metres is a mintute and second in Log and Lat

Post by Fargo 1953 » 24 January 16 9:50 am

As a newbie I am sure this is the proverbial "dumb question".
I went out to find my first cache but I wasn't really sure how close I was to it.

Need a quick lesson in reading long/lats on my garmin gps and how far away I am from the cache.

One google answer says that a Lat second is about 31 meters and Long second is about 24 meters.

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caughtatwork
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Re: How many metres is a mintute and second in Log and Lat

Post by caughtatwork » 24 January 16 11:03 am

Neither is true as it is dependant on your location. The closer to the poles the less distance betwwn longitudes.

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Papa Bear_Left
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Re: How many metres is a mintute and second in Log and Lat

Post by Papa Bear_Left » 24 January 16 12:04 pm

Your GPS almost certainly has a waypoint feature, where you enter the coords of the point you want to get to, then get a screen with the direction and distance to get there. (The "magic arrow" that has almost religious significance to geocachers! :) )

Wandering around trying to get the lat/long numbers to match up is definitely doing things the hard way!

Have a read of the manual (which you should be able to download from Garmin if you don't have the original)

RebornCyclist
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Re: How many metres is a mintute and second in Log and Lat

Post by RebornCyclist » 24 January 16 2:52 pm

In the case of latitude, it will be in the vicinity of 31 metres per second, or, probably more usefully, 1.85 metres per thousandth of a minute (since that's how geocaching coords are usually presented).
Longitude varies from about the same at the equator (1.85km/minute) to 0 at the poles, as the lines on longitude get closer and closer together (like the lines between the segments on a Terry's chocolate orange - mmmm, chocolate orange).
In fact, it'll be 1.85 times the cosine of the latitude.
In Victoria, that's about 1.5m.

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Just a cacher
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Re: How many metres is a mintute and second in Log and Lat

Post by Just a cacher » 24 January 16 4:32 pm

Why don't you tell us what GPSr model you are using?
Someone is bound to have something similar, if not the same, and might be able to help you to understand it. (Most likely not me, I hasten to add - I am useless with tech.)

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Re: How many metres is a mintute and second in Log and Lat

Post by MavEtJu » 24 January 16 5:17 pm

I use this in GeoCube: http://www.movable-type.co.uk/scripts/latlong.html

And thanks to the power of the newer editors and compilers, I can use the same Greek symbols in the code:

Code: Select all

+ (NSInteger)coordinates2distance:(CLLocationCoordinate2D)c1 to:(CLLocationCoordinate2D)c2
{
    // From http://www.movable-type.co.uk/scripts/latlong.html
    float R = 6371000; // radius of Earth in metres
    float φ1 = [self toRadians:c1.latitude];
    float φ2 = [self toRadians:c2.latitude];
    float Δφ = [self toRadians:c2.latitude - c1.latitude];
    float Δλ = [self toRadians:c2.longitude - c1.longitude];

    float a = sin(Δφ / 2) * sin(Δφ / 2) + cos(φ1) * cos(φ2) * sin(Δλ / 2) * sin(Δλ / 2);
    float c = 2 * atan2(sqrt(a), sqrt(1 - a));

    float d = R * c;
    return d;
}

LouiseAnn
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Re: How many metres is a mintute and second in Log and Lat

Post by LouiseAnn » 25 January 16 11:35 am

RebornCyclist wrote: (like the lines between the segments on a Terry's chocolate orange - mmmm, chocolate orange).
Now I want a chocolate orange.

Also, good answer

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Fargo 1953
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Re: How many metres is a mintute and second in Log and Lat

Post by Fargo 1953 » 26 January 16 9:32 am

Thanks everyone.
I have a Garmin eTrex 10 and the manual is very brief. :(
I tried to enter the coordinates but could not figure out how to. Got to the correct screen but didn't seem to allow me to put in coords.
I will have to down load a more extensive "manual", assuming one exists.
I want that magic arrow to point me in the right direction!!!!! \:D/

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Re: How many metres is a mintute and second in Log and Lat

Post by biggles1024 » 26 January 16 11:14 am

Fargo 1953 wrote:Thanks everyone.
I have a Garmin eTrex 10 and the manual is very brief. :(
I tried to enter the coordinates but could not figure out how to. Got to the correct screen but didn't seem to allow me to put in coords.
I will have to down load a more extensive "manual", assuming one exists.
I want that magic arrow to point me in the right direction!!!!! \:D/
Check YouTube for tutorials on your Garmin eTrex 10. There appear to be a number of tutorials available, too many for me to start providing links here.

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Fargo 1953
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Re: How many metres is a mintute and second in Log and Lat

Post by Fargo 1953 » 27 January 16 8:14 am

Downloaded the manual and heaps of "How to" on You Tube.

Cache's here I come......................(I hope).... :lol:

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