Lattitude and longitude formats, an obvious observation

[FairweatherDave]

This is all very obvious really, but I found it interesting. Reading the stuff about GPS rollover and checking your equipment I thought I would check mine, even though I think it is all too young to worry about. So two Garmin GPS 72 s and an E trek, plus my Lenovo tablet with Marine Navigator app. The Garmins all correlated but not at all with my tablet, although the tablet showed me to be exactly in the right place on the screen. It took me quite a while to twig that the tablet was using a different format (5 decimal places). I don't use the tablet for navigation that much and I'm not sure in normal circumstances you would use it for position that often, you just look at where it places you on the chart. So the exercise was a good reminder about formats. I hope in the unlikely event of a non DSC mayday I'd get the format right

Just to show the difference (were anyone interested) 0 degrees57.608' W, is the same as 0.96013 W. Took me too long to feel happy about that!

 

[RichardS]

We have plenty of posts on YBW over the years where posters have got confused between the different formats so the confusion certainly does happen in the "real" world.

Richard

 

[LadyInBed]

If you use an app like Mad Mutt Marine or Saildroid you get the readout in 'standard' format.

 

[penberth3]

This is all very obvious really, but I found it interesting. Reading the stuff about GPS rollover and checking your equipment I thought I would check mine, even though I think it is all too young to worry about. So two Garmin GPS 72 s and an E trek, plus my Lenovo tablet with Marine Navigator app. The Garmins all correlated but not at all with my tablet, although the tablet showed me to be exactly in the right place on the screen. It took me quite a while to twig that the tablet was using a different format (5 decimal places). I don't use the tablet for navigation that much and I'm not sure in normal circumstances you would use it for position that often, you just look at where it places you on the chart. So the exercise was a good reminder about formats. I hope in the unlikely event of a non DSC mayday I'd get the format right

Just to show the difference (were anyone interested) 0 degrees57.608' W, is the same as 0.96013 W. Took me too long to feel happy about that!

A good reminder to always check units, scales etc!

Would it be less confusing if the programmer avoided decimals of a minute and displayed the fraction as seconds? Perhaps not!

 

[mjcoon]

Would it be less confusing if the programmer avoided decimals of a minute and displayed the fraction as seconds? Perhaps not!

Aren't paper charts marked up with decimal minutes these days?

Mike.

 

[dolabriform]

Aren't paper charts marked up with decimal minutes these days?

Mike.

Yes

 

[FairweatherDave]

Okay. To standardise this conversation
Garmin gives three options on my handhelds
1. hddd.ddddd degrees
2 hddd degrees mm.mmm'
3 hddd degrees mm'ss.s"

(sorry, don't know how to show the degrees symbol)
To which option are you referring with "decimal minutes" on the paper charts?

(Apols for the clumsy English, just trying for clarity, not trying to sound confrontational!)

 

[Telstar26]

The excellent Marine Navigator app lets you choose the lat/long format, just go to Settings and it's the first option.

 

[FairweatherDave]

Okay. To standardise this conversation
Garmin gives three options on my handhelds
1. hddd.ddddd degrees
2 hddd degrees mm.mmm'
3 hddd degrees mm'ss.s"

(sorry, don't know how to show the degrees symbol)
To which option are you referring with "decimal minutes" on the paper charts?

(Apols for the clumsy English, just trying for clarity, not trying to sound confrontational!)

I'm learning
Option 1. is decimal degrees
Option 2. is decimal minutes
Option 3 is sexagesimal

My GPS were set to option 2 and my tablet to option1. As stated, I haven't used my tablet much with Marine Navigator, even less to look at lat and long. But I will set it to option2

 

[guernseyman]

Okay. To standardise this conversation
Garmin gives three options on my handhelds
1. hddd.ddddd degrees
2 hddd degrees mm.mmm'
3 hddd degrees mm'ss.s"

(sorry, don't know how to show the degrees symbol)
To which option are you referring with "decimal minutes" on the paper charts?

(Apols for the clumsy English, just trying for clarity, not trying to sound confrontational!)

If you want to do something like use a Special Character when posting on this forum, compose your post in your Word Processor and copy in to your post, like this:

Okay. To standardise this conversation
Garmin gives three options on my handhelds
1.*hddd.ddddd º
2 hddd º*mm.mmm'
3 hddd º mm'ss.s"

 

[mjcoon]

If you want to do something like use a Special Character when posting on this forum, compose your post in your Word Processor

Even on my Win-10 system, I still have the ancient Character Map program which allows copying any character you can find in its multiple repertoires... Some browsers may have something similar.

Mike.

 

[FairweatherDave]

Well I am learning more! I have cracked putting it into word, and
° !
Not that easy, not that hard.....hopefully I will remember next time

Could not get alt 0176 to work but found insert symbols in the word program

Was more excited about option 2 v option 1 so typing degree was a secondary issue

°°°°°°°

 

[guernseyman]

Even on my Win-10 system, I still have the ancient Character Map program which allows copying any character you can find in its multiple repertoires... Some browsers may have something similar.

Mike.

Thanks for that.

 

[Frank Holden]

On my Mac I simply use * for degrees... maybe there is an easier and better way some one would like to share.

What makes me wonder about some people is when... at sea or indeed anywhere else... they give their position to three decimal places of a minute.... ie 41* 27.321'S .....

In fact I wonder when people use any decimal places when at sea...

It always demonstrates a certain lack of understanding..... what with 0.001 being about 1.7 metres or so ( of latitude... less if you are talking about longitude ) .... I often feel like asking what end of the boat they are talking about...

Sure, it has its place when surveying a new anchorage or similar.

 

[prv]

On my Mac I simply use * for degrees... maybe there is an easier and better way some one would like to share.

Certainly - just type alt-0 (zero).

Lots of other characters are available with alt-<something>, or alt-shift-<something>, usually with some sort of mnemonic or other connection. For example, alt-s for ß, alt-o for ø, alt-= for ≠, and so on. In some cases what alt- gives you is just the diacritic, hovering over an empty space, and then you type the character it belongs with - so for example alt-u gives you a prospective umlaut, then if you follow it with an ordinary o you get ö. You can't put an umlaut over any letter though, only ones where it makes sense in some language's writing system.

My Linux machine at work does something similar, albeit not quite as complete or elegant. I don't know if modern Windows does too, but for whatever reason most Windows people seem to stick with their silly clunky three-digit codes.

Pete

 

[Kukri]

Old habits are hard to break.

Yottigator pokes head out of hatch. Says nothing. Breathes in, and proceeds to quarter the horizon intently, remaining silent.

After a couple of minutes of this, the nut on the wheel can scarcely contain her/his impatience.

Yottigator gives the distant and inscrutable horizon another Hard Stare, smiles at the nut on the wheel, and says, quoting Gilbert and Sullivan;

“What a pleasant spot! I wonder where we are?”

 

[requiem]

On my Mac I simply use * for degrees... maybe there is an easier and better way some one would like to share.

For mine, option-shift-8 gives the degree symbol: °, option-zero gives the similar but more obscure "ordinal indicator": º.

What makes me wonder about some people is when... at sea or indeed anywhere else... they give their position to three decimal places of a minute.... ie 41* 27.321'S .....

It's useful as a warning flag, I suppose, just as the selection of display format can be. The first thing I do with any new navigational device or app is to set to MGRS if for land, and decimal minutes if for sea. What's really annoying is encountering modern charts that don't use decimal minutes.

 

[Frank Holden]

For mine, option-shift-8 gives the degree symbol: °, option-zero gives the similar but more obscure "ordinal indicator": º.

O ... for just a minute there I thought this was going to be all very simple....

 

[Buck Turgidson]

on my mac I have ° symbol first key second row. but I do have a Swiss german keyboard!! éàèöäü

 

[prv]

For mine, option-shift-8 gives the degree symbol: °, option-zero gives the similar but more obscure "ordinal indicator": º.

Huh. In which case I withdraw my advice to Frank in favour of yours - apparently for all these years I've been erroneously drawing "ordinal indicators" all over the place.

Since the only visible difference is that the circle appears very slightly bigger, I doubt anybody noticed

Pete