gps coordinates

[Retterath]

when I'm searching on google earth and looking at coordinates i see that they would be
45deg32'45.14"N 100deg 24'28.18"w so for example if i were to put them into my gps my gps asks for them a little different way. When i go to the same spot on my gps this is how they are example(N45deg 32.510 W100deg 26.313')


for the first set of coordinates i gave u 45deg32'45.14"N 100deg 24'28.18"w how would the north numbers be entered i don't get the 45.14 because in my gps there is no decimal point for the second set of number and i can't get one in there.Or do i just enter it as 4514

sorry if this is really confusing.

 

[libidilatimmy]

Lat-Long is expressed in Degrees, Minutes, and Seconds, or a variation thereof. Google Earth is supplying the lat, long in NDD-MM-SS.SS format. Your GPS wants you to input the same coordinate in NDD-MM.MMM format. To convert from DD-MM-SS.SS to DD-MM.MMM simply divide the seconds in the coordinate by 60 and add that number to the minutes. SS.SS/60=0.MMM

 

[libidilatimmy]

Also, in some GPS units to get it to a West Longitude, you simply enter the coordinate as a negative or -100 degrees. You'll know if you made that error right away if it's telling you to navigate somewhere in Turkey.

 

[Umpqua Hunter]

Or in Google Earth you can change the format of the coordinates. This is the format I use on both Google Earth and my Garmin GPS.

110° 14.851'W

 

[libidilatimmy]

Or in Google Earth you can change the format of the coordinates. This is the format I use on both Google Earth and my Garmin GPS.

110° 14.851'W

Yes you can. Still need to know how to convert the coordinates though cause quad maps don't have an options menu. [emoji6]

 

[Retterath]

Lat-Long is expressed in Degrees, Minutes, and Seconds, or a variation thereof. Google Earth is supplying the lat, long in NDD-MM-SS.SS format. Your GPS wants you to input the same coordinate in NDD-MM.MMM format. To convert from DD-MM-SS.SS to DD-MM.MMM simply divide the seconds in the coordinate by 60 and add that number to the minutes. SS.SS/60=0.MMM

so for 45deg 32' 45.14"N i take the 45.14/60+32=32.75233 So i input it in gps like 45deg32.75'

 

[Triple BB]

IMO lat & long coordinates are worthless with a GPS. Change your GPS to UTM's and do the same with google earth and you'll be comparing apples to apples without having to convert anything. UTM's are also a lot easier to work with on quad maps...

 

[libidilatimmy]

so for 45deg 32' 45.14"N i take the 45.14/60+32=32.75233 So i input it in gps like 45deg32.75'

Yep, except you'll want to carry the number out to the 3rd decimal place for accuracy.

 

[Retterath]

ok awesome thanks so much.

 

[Retterath]

IMO lat & long coordinates are worthless with a GPS. Change your GPS to UTM's and do the same with google earth and you'll be comparing apples to apples without having to convert anything. UTM's are also a lot easier to work with on quad maps...

i was looking on my gps for changing it but don't think i can. I have a garmin 450t

 

[Triple BB]

Try paging to the main menu, then set up, then units. Convert to UTM UPS and make sure its set on NAD 27 Conus.

 

[Retterath]

Try paging to the main menu, then set up, then units. Convert to UTM UPS and make sure its set on NAD 27 Conus.

i went through all that and don't find anything on changing what u stated, I don't think i can.

 

[libidilatimmy]

IMO lat & long coordinates are worthless with a GPS. Change your GPS to UTM's and do the same with google earth and you'll be comparing apples to apples without having to convert anything. UTM's are also a lot easier to work with on quad maps...

Can be easier if you are aware what you're dealing with. Lat, Long coordinates are 3D coordinates whereas UTM are 2D coordinates. The very same UTM coordinate represents two very different places on the ground with a projection set at sea level and the projection set at 10000ft. Plane coordinates (UTM, State Plane, etc) are a flat system projected on a curved surface bound by Lat-Long coordinates in two corners. As with any defined plane system, you have to make sure you have the proper zone in the system selected and an approximate elevation for the projection set whereas with Lat-Long all you need and Lat-Long is what your GPS is really running on no matter the coordinate it is outputting, is just converting a particular Lat-Long to a particular N-E.

 

[Retterath]

Yep, except you'll want to carry the number out to the 3rd decimal place for accuracy.

So now if i get a waypoint on my gps and want to convert it to the google earth method i suppose i can change it on the menu which i can't find or can i do i get it to the way they have it on google earth

 

[libidilatimmy]

So now if i get a waypoint on my gps and want to convert it to the google earth method i suppose i can change it on the menu which i can't find or can i do i get it to the way they have it on google earth

For the math conversion, take the decimal portion of the Minutes and multiply by 60. 0.MMMx60=SS.SS

 

[Retterath]

Can be easier if you are aware what you're dealing with. Lat, Long coordinates are 3D coordinates whereas UTM are 2D coordinates. The very same UTM coordinate represents two very different places on the ground with a projection set at sea level and the projection set at 10000ft. Plane coordinates (UTM, State Plane, etc) are a flat system projected on a curved surface bound by Lat-Long coordinates in two corners. As with any defined plane system, you have to make sure you have the proper zone in the system selected and an approximate elevation for the projection set whereas with Lat-Long all you need and Lat-Long is what your GPS is really running on no matter the coordinate it is outputting, is just converting a particular Lat-Long to a particular N-E.

Great job of explaining it. well done. thanks for the info and clarification.

 

[libidilatimmy]

Great job of explaining it. well done. thanks for the info and clarification.

Not a problem, buddy. I was a surveyor for 10 yrs so this stuff is second nature to me, so to speak. Any of the systems will work, as long as you're aware what you're being told/inputting.

 

[Triple BB]

Ret, get yerself a Garmin 60, 62, or 64 and set it to UTM's if yer 450 can't be changed. Rather than hash out which is better, read some of this article starting with where it states, "Why use the UTM coordinate system?" Fact is, UTM's are more precise and far easier to use than lat/lon. If you check out any of the hardcore GPS/geocaching websites, you'll see almost everyone uses UTM's. The military developed UTM's in the 40's and then morphed it into the system they currently use called MGRS.

http://therucksack.tripod.com/MiBSAR/LandNav/UTM/UTM.htm

Good luck...

 

[libidilatimmy]

Fact is, UTM's are more precise and far easier to use than lat/lon.

Yes, a N-E coordinate is easier for us to quantify because the coordinate refers to a unit of lineal measurement being either feet or meters. While when looking at a UTM coordinate, the Northing looks something like this, N4792563.21. This coordinate is accurate to 1/100th of a foot. The Latitude that corresponds to that particular UTM coordinate looks like this, N43-12-24.8256. This coordinate is also accurate to 1/100th of a foot. For demonstration purposes, 1 second of latitude equals roughly 100 feet. Both coordinate systems are equally accurate and inaccurate as you wish to make them.

The constraint on the accuracy actually lies within the device itself, which for most handheld GPS units is in the neighborhood of +/-1 to 2 meters in normal conditions. So, even if your handheld device is displaying coordinates to the level of precision as shown above, it really can't take you to the same exact place on the earth within a couple feet with any sort of reliability due to the units processor capabilities. With the newer handheld units, repeatable accuracy in the 5-10 ft range is more in the ballpark. This is why most handheld units want you to enter Lat-Long coordinates in DD-MM.MMM format. The reasoning behind this is that the 3rd decimal place equals roughly 5 feet and is within the positional accuracy tolerances of the device itself. The bottom line is that the user should use whatever coordinate system they feel comfortable with and learn how to use the device itself. A GPS unit that you can't operate effectively does the user about as much good as a rifle that's not sighted in.