Standard GPS format??
 

It's been suggested

"a suggestion if I may.
Is there any way to encourage individuals (HU community
ditto) to use a standard format for Lat & Longitude ? for
example :
N51 30.729 W0 03.904 (london) ?
it would make like (cut & paste) soooooo much simpler IMHO. Bertrand"

MY question as a non-regular GPS user is: What IS the most common format?

IS WGS84 the standard WORLD-wide or?

What should HUBBers try to standardise on or is it a hopeless task?

Let me know the common formats and I'll post a poll to get a vote on it.

thanks!

Seems like a good idea. I'm in favour of the above London example as it matches the Garmin Mapsource format so you can paste it straight into a waypoint and it works.
Stephan

Coordinate display
 

WGS84 is not a format that causes most confusion, as it is actually default map datum in many applications and GPS hardware. It is good idea to have it as default unless you want to use some exotic maps that use different grid (soviet military maps etc).

The actual problem in the internet is showing/writing the same point coordinates in different ways:

1) As decimal degrees (D,DDDDD): N 58.88482°, E 25.56835 °
2) As degrees and minutes (DD MM,MMM): N 58° 53.089', E 25 ° 34.101'
3) As degrees, minutes and seconds (DD MM SS,S): N 58° 53' 5.3 ", E 25 ° 34' 6.1 "

All the above are referring exactly the same location. You can cange your GPS to display which format you prefer, however, beware of entering coordinates in "wrong" format as this will cause errors.

Which of the above 3 is best? Hard to tell, but if I remember right default Garmin setup is DD MM,MMM (example 2 above). But to use Google Maps API for example, you pass decimal coordinates (D,DDDDD) that makes the application easy to process them as there is no need to convert from minutes and seconds. Also I think most GPS hardware and software store point coordinates as D,DDDDD internally, the other formats will just be displayed on demand (by converting).

many digits, many mistakes
 

My 2 cents:

WGS84 seems to be the most used map-datum and it is important since it converts de coordinates into a location. Having the wrong datum takes you to the wrong spot on the map, but two people using different datums is more confusing.

As for the format I absolutely prefer the DD.MM.mmm version.
In the metric system we do not use more then 3 digits in a row since that is the maximum amount of digits the human eye (read brain) can "read in a glance". With more than 3 digits most people need to count the position and need to "remember them" in more than one pass.

Also I would prefer "all digits" so london would be N 51 30.729 W 000 03.904 and not N51 30.729 W0 03.904.
It shows what kind of format is used more clearly.

The "old system" DD.MM.SS is just not acurate enough for modern devices.

Ofcourse this is only my very humble opinion.

:mchappy: Maarten

Decimal Degrees
 

As in hddd.ddddd as in: N58.88482, E25.56835 would be simplest.
Its also the one Google maps uses so there exists a load of references.

I use a site called POI66 and that is also the format they use.
My (garmin) GPS is also set to that.

WGS 84 is the reference system being used by the Global Positioning Systems. It is geocentric and globally consistent within ±1 m.
So it would seem good sense to use it:smartass:

John

Hi,
from what I found out:
WGS84 is the 'map datum'. Dat means every latitude/longitude will bring you to a certain location. Using NAD27 would give a different location for the same coordinate! WGS84 is what GPS uses, but you can change that often to match map's 'datum'.

The presentation layer can be UTM (translation to XY in meters per map cell), or the degree thing (always latitude first, then longitude). Common in mapping was: degrees°minutes'seconds" but computers can't cope with that easily and users don't know how to enter that. Also with degrees°minutes.fractionminutes'.

I would suggest to use degrees in the hddd.ddddd format: 52.52121 degrees is (vertically) 1.11 meters per 0.00001 degree. Horizontally (Greenwich Meridian distance) it depends on the latitude, but 'here' in Amsterdam/London every 0.00001 degree is 0.68 meters.

I would say: WGS84 and hddd.ddddd is the right standard. A pity that Google start up in some other presentation. Tools->Options->set to degrees to make life easier.