Formula for EPSG:4362 and questions to mercator projection?

classic Classic list List threaded Threaded
5 messages Options
Reply | Threaded
Open this post in threaded view
|

Formula for EPSG:4362 and questions to mercator projection?

Immanuel Scholz
Hi,

can someone explain me the formula for the projection "EPSG:4362" used in
WGS84?

It looks a bit like a mercator projection but with the pole not as much
distorted... ?



And when we are on it: The mercator projection can not project the north- and
south pole correctly. A picture of the whole world would be infinite in
height.

How comes, that there are maps of the whole world in mercator projection?
http://en.wikipedia.org/wiki/Image:Mercator-proj.jpeg

Are there a standard at which latitude the projection stops? If I stop at +-85
degree of latitude, I get a map with roughly equal dimension in width and
height. Is the "border latitude" for mercator somewhere there?

Or is some kind of magic used to project the near-pole regions in mercator
projection and the formular at
http://en.wikipedia.org/wiki/Mercator_projection is simple wrong?


Ciao, Imi.

_______________________________________________
Openstreetmap mailing list
[hidden email]
http://bat.vr.ucl.ac.uk/cgi-bin/mailman/listinfo/openstreetmap
Reply | Threaded
Open this post in threaded view
|

RE: Formula for EPSG:4362 and questions to mercatorprojection?

ANDY ROBINSON-2
EPSG:4362 is the unprojected Lat and Lon WGS84 is it not??

Not sure if this document is of any use in answering your question but I
find it generally of interest whenever I need to get my head around
something relating to the shape of our good planet and the transformation of
that shape.

http://www.gps.gov.uk/additionalInfo/images/A_guide_to_coord.pdf

Andy

Andy Robinson
[hidden email]

>-----Original Message-----
>From: [hidden email] [mailto:openstreetmap-
>[hidden email]] On Behalf Of Immanuel Scholz
>Sent: 12 January 2006 23:57
>To: [hidden email]
>Subject: [Openstreetmap] Formula for EPSG:4362 and questions to
>mercatorprojection?
>
>Hi,
>
>can someone explain me the formula for the projection "EPSG:4362" used in
>WGS84?
>
>It looks a bit like a mercator projection but with the pole not as much
>distorted... ?
>
>
>
>And when we are on it: The mercator projection can not project the north-
>and
>south pole correctly. A picture of the whole world would be infinite in
>height.
>
>How comes, that there are maps of the whole world in mercator projection?
>http://en.wikipedia.org/wiki/Image:Mercator-proj.jpeg
>
>Are there a standard at which latitude the projection stops? If I stop at
>+-85
>degree of latitude, I get a map with roughly equal dimension in width and
>height. Is the "border latitude" for mercator somewhere there?
>
>Or is some kind of magic used to project the near-pole regions in mercator
>projection and the formular at
>http://en.wikipedia.org/wiki/Mercator_projection is simple wrong?
>
>
>Ciao, Imi.
>
>_______________________________________________
>Openstreetmap mailing list
>[hidden email]
>http://bat.vr.ucl.ac.uk/cgi-bin/mailman/listinfo/openstreetmap



_______________________________________________
Openstreetmap mailing list
[hidden email]
http://bat.vr.ucl.ac.uk/cgi-bin/mailman/listinfo/openstreetmap
Reply | Threaded
Open this post in threaded view
|

RE: Formula for EPSG:4362 and questions tomercatorprojection?

ANDY ROBINSON-2
Oh, and this one of course:

http://www.epsg.org/guides/docs/G7-2.pdf


Andy Robinson
[hidden email]

>-----Original Message-----
>From: [hidden email] [mailto:openstreetmap-
>[hidden email]] On Behalf Of Andy Robinson
>Sent: 13 January 2006 09:33
>To: [hidden email]
>Subject: RE: [Openstreetmap] Formula for EPSG:4362 and questions
>tomercatorprojection?
>
>EPSG:4362 is the unprojected Lat and Lon WGS84 is it not??
>
>Not sure if this document is of any use in answering your question but I
>find it generally of interest whenever I need to get my head around
>something relating to the shape of our good planet and the transformation
>of
>that shape.
>
>http://www.gps.gov.uk/additionalInfo/images/A_guide_to_coord.pdf
>
>Andy
>
>Andy Robinson
>[hidden email]
>>-----Original Message-----
>>From: [hidden email] [mailto:openstreetmap-
>>[hidden email]] On Behalf Of Immanuel Scholz
>>Sent: 12 January 2006 23:57
>>To: [hidden email]
>>Subject: [Openstreetmap] Formula for EPSG:4362 and questions to
>>mercatorprojection?
>>
>>Hi,
>>
>>can someone explain me the formula for the projection "EPSG:4362" used in
>>WGS84?
>>
>>It looks a bit like a mercator projection but with the pole not as much
>>distorted... ?
>>
>>
>>
>>And when we are on it: The mercator projection can not project the north-
>>and
>>south pole correctly. A picture of the whole world would be infinite in
>>height.
>>
>>How comes, that there are maps of the whole world in mercator projection?
>>http://en.wikipedia.org/wiki/Image:Mercator-proj.jpeg
>>
>>Are there a standard at which latitude the projection stops? If I stop at
>>+-85
>>degree of latitude, I get a map with roughly equal dimension in width and
>>height. Is the "border latitude" for mercator somewhere there?
>>
>>Or is some kind of magic used to project the near-pole regions in mercator
>>projection and the formular at
>>http://en.wikipedia.org/wiki/Mercator_projection is simple wrong?
>>
>>
>>Ciao, Imi.
>>
>>_______________________________________________
>>Openstreetmap mailing list
>>[hidden email]
>>http://bat.vr.ucl.ac.uk/cgi-bin/mailman/listinfo/openstreetmap
>
>
>
>_______________________________________________
>Openstreetmap mailing list
>[hidden email]
>http://bat.vr.ucl.ac.uk/cgi-bin/mailman/listinfo/openstreetmap



_______________________________________________
Openstreetmap mailing list
[hidden email]
http://bat.vr.ucl.ac.uk/cgi-bin/mailman/listinfo/openstreetmap
Reply | Threaded
Open this post in threaded view
|

Re: Formula for EPSG:4362 and questions to mercator projection?

Mikel Maron
In reply to this post by Immanuel Scholz
My understanding is that EPSG:4326 specifies a projection,
with WGS84 as the Coordinate Reference System (the agreed abstract geometry of the earth)
and no coordinate transformation (really, the sphere of the earth is projected into 2D onto a cylinder)

That wikipedia Mercator map does appear to stop before the poles, couldn't say precisely at what latitude though.

----- Original Message ----
From: Immanuel Scholz <[hidden email]>
To: [hidden email]
Sent: Thursday, January 12, 2006 11:56:42 PM
Subject: [Openstreetmap] Formula for EPSG:4362 and questions to mercator projection?

Hi,

can someone explain me the formula for the projection "EPSG:4362" used in
WGS84?

It looks a bit like a mercator projection but with the pole not as much
distorted... ?



And when we are on it: The mercator projection can not project the north- and
south pole correctly. A picture of the whole world would be infinite in
height.

How comes, that there are maps of the whole world in mercator projection?
http://en.wikipedia.org/wiki/Image:Mercator-proj.jpeg

Are there a standard at which latitude the projection stops? If I stop at +-85
degree of latitude, I get a map with roughly equal dimension in width and
height. Is the "border latitude" for mercator somewhere there?

Or is some kind of magic used to project the near-pole regions in mercator
projection and the formular at
http://en.wikipedia.org/wiki/Mercator_projection is simple wrong?


Ciao, Imi.

_______________________________________________
Openstreetmap mailing list
[hidden email]
http://bat.vr.ucl.ac.uk/cgi-bin/mailman/listinfo/openstreetmap




_______________________________________________
Openstreetmap mailing list
[hidden email]
http://bat.vr.ucl.ac.uk/cgi-bin/mailman/listinfo/openstreetmap
Reply | Threaded
Open this post in threaded view
|

Re: Formula for EPSG:4362 and questions to mercator projection?

Thomas Walraet
Mikel Maron a écrit :
>
> That wikipedia Mercator map does appear to stop before the poles, couldn't say precisely at what latitude though.

http://en.wikipedia.org/wiki/Mercator_projection

It's written just below the map :
« The Mercator projection of the world up to a latitude of 84° N and S »


_______________________________________________
Openstreetmap mailing list
[hidden email]
http://bat.vr.ucl.ac.uk/cgi-bin/mailman/listinfo/openstreetmap