[Gvsig_english] scalebar in EPSG 4326 (wgs 84 World 2D)

[Juan Lucas Dominguez Rubio]

Hello,
 
Benjamin's comment makes a lot of sense as usual.
 
Nevertheless, a gvSIG view in EPSG:4326 still shows a value for the scale denominator, which I presume refers to the scale along the Equator.
 
I think a map without a scale in somewhat incomplete.
 
If your map is in EPSG:4326, I recommend to add a scale bar with a little comment by its side that says something like: "Approximate scale, valid along the Equator and along meridians" (because the length of the Equator is about the same as the length of every meridian, with an error of perhaps 0.5% or less, which is not very important)
 
Regards,
Juan Lucas Domínguez Rubio
---
Prodevelop SL, Valencia (España)
Tlf.: 96.351.06.12 -- Fax: 96.351.09.68
http://www.prodevelop.es <http://www.prodevelop.es/> 
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________________________________

De: gvsig_internacional-bounces at listserv.gva.es en nombre de Benjamin Ducke
Enviado el: lun 23/05/2011 17:45
Para: Users and Developers mailing list
Asunto: Re: [Gvsig_english] scalebar in EPSG 4326 (wgs 84 World 2D)



Hi Carsten --

EPSG 4326 is an unprojected geodetic system.
Since no projection to cartesian coordinate space is done,
the scale of the displayed data varies, depending on where you
measure it -- that's why there are no globes with scale bars
printed on them ;). All you could do is draw an estimated
scale bar yourself in an external program and then import
that into your gvSIG map layout.

Alternatively, you can project your data into a cartesian
system, such as UTM and work with that.

Ben

----- Original Message -----
> Hello,
>
> I'd like to add a scalebar in a map created from a view using the EPSG
> 4326 (WGS84 word 2D) Projection.
> Unfortunately, the scalebar function does not work as correct as in
> some other projections. I searched for a solution in the faq, but did
> not find a result.
> Also the scale seems to be announced wrong. (Europe in DIN-A4 is like
> 1:1). Is there a possibility to solve this problem?
> Regards Carsten Mischka
>
> _______________________________________________ Gvsig_internacional
> mailing list
> Gvsig_internacional at listserv.gva.es
> http://listserv.gva.es/cgi-bin/mailman/listinfo/gvsig_internacional


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