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Discussion Starter #1
This may have the impact of a chihuahua barking at the moon, but there are three different ways that lat. and long. are presented for us to use in determining where we are.

My front door is at:

N 29° 53.103’
W 098° 27.415’



It is also at:

N 29° 53' 6.18"
W 098° 27' 24.9"



And furthermore, it is at:

N 29.88505°
W 098.456916°

Now, to me, the last one is the easiest, becasue it is just a number. However, Garmin uses the first one, with degrees and minutes and fractions of minutes.

Some maps give degrees, minutes, and seconds and fractons of seconds. It requires a calculator in any case to move from one format to the other.

One of the sites I use to preplan where I an going is Latitude/Longitude Postioin Finder whcih can be found at:
http://www.juggling.org/bin/un.cgi/map-find

It outputs data in Degrees and fractions, so to get data useful to Garmin, the decimal fraction of a degree must then be converted to minutes and fractions of minutes by multiplying by 60.

I am wondering if I am the only one that feels the annoyance of multiple methods of displaying the positioin data, or are there others that would feel their navigation was easier if the format was down to just one and if so, which of the three would you prefer?
 

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my front door is exactly there...at the front of my house!!!.... :D :D :D and that is where I prefer it.... :a13:
 

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Tom,

You bring up a good point. But I have got to be honest with you. Unless am on a bombing or strafing mission, I don't pay a lot of attention to Lat & Long. A simple address suits me just fine.

Bulldog
 

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1 degree Latutide = 60 (NM) nautical miles
1 minute - l NM
1 second - 1/60 NM

(1 degree Longitude = cosine latitude)

The displays are nothing more than experessing the above coordinates in decimal units.
 

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Discussion Starter #5
Barking at the moon

It seems like I missed pretty well a point I was trying to make. For those who use the GPS extensively, having to use the base 60 is clumsey when you are conversing with some using the base 10. Kind of like two guys building a house and one has a yard stick and the other has a meter stick.

I guess it will be some years before GPS becomes the primary way the general population finds the location they are looking for.

I use GPS for all locations before I leave on a trip. Being in a record setting thunderstorm in Chicago on my 93 Wing trying to navigate by map pretty in 5 lanes of 18 wheelers pretty well cured me of using a map on a bike.

Probably sounds strange to those who only ride occasionally and then short trips in the sunshine. I often ride 1200 miles or more bed to bed and that means night and rain and whatever else gets in the way. If you throw into that the need to read a paper map, it becomes a bit much, especially since we now have a fabulous alternative.

The point I was trying to make is that as GPS gets to be more of a primary navigation means for most of us, it would be nice to always publish and use the locations of latitude and longitude in one format of the three in primary use, and in the interest of simplicity I would propose that this is in degrees to several decicmal points, rather than n degrees, n/60th degree, and n/60th of n/60th of a degree to get within a few feet of our sought location.
 

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While you are barking at the moon, Tom, why not start with the degrees part. Why 360 degrees in a circle? Why not 100 (base 10)? Or maybe 400 so we could have 100 in each quadrant? And why Quadrants?

Lets look at the mile. Metric mile, statute mile, or nautical mile? Are they measured in feet, yards, leagues, or angstrom units?

Lets face it. We can't even agree on what time it is, let alone how far.

So, I'm just going to enjoy the moon and think of all that cheese....:lol:
 

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IR Harry said:
While you are barking at the moon, Tom, why not start with the degrees part. Why 360 degrees in a circle? Why not 100 (base 10)? Or maybe 400 so we could have 100 in each quadrant? And why Quadrants?
I use UTM (Universal Transverse Mercator) coordinates that are in fact perfectly rectangular grids with values in meters. All GPS' can be set to this and maps using UTM are easy to get too. It is way easier to find a location on a map with UTM coordinates. Give it a try.
 

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LETS GET SILLY, my mailbox is exactly 83.4 feet from my front door. now thats gps to the silly.

loren
 

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Tom, you should be able to change your garmin to display the coordinates any way you want. I have the etrex vista and have it set like your #3 format. Check your manual to see how to do it for yours.
 

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I use both of my Garmin GPS units primarily for work. Putting one of them on the bike is a bonus. The decimal format ie: 39.1234 41.5678 is what is used for the FCC registration of radio towers, and what I use daily. I think (don't quote me), the degree format ie: 39.14.24 41.23.34 expressed as minutes and seconds is how it's been done since ships at sea had sails. However, this format is hard for computers to deal with.... thus the conversion to a decimal format.
 

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Discussion Starter #11
Two new ideas

Thanks. I will look into both the UTM and the possibility of setting the GPS V to decimal degrees.

Right on relative to 100 or 1000 degrees per circle. The Earth was divided into quarters of 1,000 kilometers each to get the 39.37 inches in a meter. The foot was the kings foot divided by a dozen. If the earth had been divided into 1000 degrees, each degree would be 25 miles and the meter would be 25000 kilometers/33,000,000 feet or 1.32 feet and our cruising speed would be 240 kilometers per hour at our current 60 mph. Now that is really moving.

Relative to the UTM, does this system converge at the poles or have a small overlap along the edges? Maybe slightly curved edges?. Sounds interesting. Going to dogpile right now. Thanks again.
 

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SPIII

I know that with the SPIII I can change the way the coordinates are put in and also displayed, but I normally just look places us using the address or select it on the map, and if I am there, just lock in my current coordinates/location. I use the GPS a lot and don't think I have actually entered coordinates once. However, If someone provides me coordinates, I think I'll be able to get them entered in the same format.

Sorry we're all not much help, but most of us keep it pretty simple and let the 'puters do the work.
 

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Discussion Starter #13
Coordinates

Dave, you might try http://www.juggling.org/bin/un.cgi/map-find experimentally and see how it works. I hope Mapquest will some day add coordinates to its address menu. Thanks for your post.

I left earlier to lead a scheduled Saturday morning ride. There was considerable ice on my 6.5 mile back road to the highway. When I got to the meeting place, there was o one there, not a sole. I cut all those little round holes in the seat cover for nothing.

Have a good one, and ride safe.
 

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Re: Two new ideas

Tom Finch said:
Thanks. I will look into both the UTM and the possibility of setting the GPS V to decimal degrees.

Relative to the UTM, does this system converge at the poles or have a small overlap along the edges? Maybe slightly curved edges?. Sounds interesting. Going to dogpile right now. Thanks again.
Tom, I'm not sure what UTM does near the poles, but I do not think there is any overlap, I think the grids get smaller. It was/is used for ships at sea. I use it for canoe trips to the waters between Canada and Minn. It allows me to actually "see" myself moving towards or away from a location and find it on a map. Very hard to do that using lon/lat as the lines are cruved. Heres a link to convert readings to UTM http://www.cellspark.com/UTM.html . And here is alink to tell you about UTM http://mac.usgs.gov/mac/isb/pubs/factsheets/fs07701.html. Here's agreat place to get custome maps with any info you want on them. I have several I ordered with UTM on them.http://mytopo.com/ Try it, you'll like it. I have no connection with any of the links, but I have used them and found them helpful. :wink:
 

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Tom, I found another link that answers all the questions on UTM. Try http://www.maptools.com/UsingUTM/ Heres aquote from one of the many pages there. It says"Why Use UTM Coordinates

The UTM coordinate system offers the following benefits:

A square grid

UTM Provides a constant distance relationship anywhere on the map. In angular coordinate systems like latitude and longitude, the distance covered by a degree of longitude differs as you move towards the poles and only equals the distance covered by a degree of latitude at the equator. Since land navigation is done in a very small part of the world at any one time using large scale maps. The UTM system allows the coordinate numbering system to be tied directly to a distance measuring system.
"
I don't kow why more people are not using this system. It is way easier to understand. Let me know what you think. I was sure surprised to learn about it when I first found out how easy it is. :D
 
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