Coordinate Conversion

[+TDandFredia]

Greetings!

 

Can anyone tell me how to convert a lat/long currently in the format 41° 43'57"N (41 deg 43 min 57 sec N) by 49° 56'49"W (49 deg 56 min 49 sec W)to WGS 84 format? I have found several places on the Interet to do various conversions, but I haven't found any place to convert the numbers I actually have (those above) to WGS 84.

 

Or is it as simple as assuming 41 43.95(which is what 57 seconds converts to as hundredths of a minute) N by 49 56.8167 W (converting 49 seconds to hundredths)?

 

Can anyone help?

 

Terry Dillard

[+parkrrrr]

WGS84 isn't a format, it's a datum. The coordinates you have might already be in the WGS84 datum, depending on where you got them. If they're not, we'd have to know what datum they were before we could convert them, and the conversion is a hard process (made simpler by available online calculators, though.)

 

Fortunately, that's probably not really what you want. If what you want is a way to convert them to the format expected by geocaching.com, and they're already in the correct datum, then what you suggested (dividing the seconds by 60 and adding the result to the minutes) is correct. If the coordinates you have came from a GPS receiver that's set to use the WGS84 datum (if it doesn't have an option to set the datum, then it's WGS84) then you're all set.

 

[+Markwell]

My FAQ

 

Markwell

Chicago Geocachers

[solohiker]

quote:

---

Originally posted by TDandFredia:

Or is it as simple as assuming 41 43.95(which is what 57 seconds converts to as hundredths of a minute) N by 49 56.8167 W (converting 49 seconds to hundredths)?

 

Can anyone help?

 

Terry Dillard

---

 

Terry, it is that simple.

 

Coordinates are recorded per a specific map datum with a variety of formats.

 

Your original coordinate format is:

 

Hddd mm ss

 

The format that you changed it to (and the format used by geocaching.com)

 

Hddd mm.mmm

 

The conversion is as you assumed. Your GPS will change between the various formats.

 

The format does not define which datum is being used so you need to be familiar with both terms and their relation to one another.

[+TDandFredia]

I appreciate everyone taking time to help me. I tried my original idea, and it worked fine.

 

The coordinates I gave came from a MobileDB (Palm OS) database which is actually a timeline of the sinking of the Titanic. In the database it gave the coordinates for where the bow and stern sections are now located on the ocean floor (the coordinates I gave were for the bow section). When I plugged them in to my GPS unit (a useful subterfuge for demonstrating the thing to the uninitiated), it showed the coordinates right where I expected them to be.

 

Thanks for the help, everyone!