Problem with on th efly projection between 27572 and 2154

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Problem with on th efly projection between 27572 and 2154

DIOT Clément

Hi all,

 

I just suscribed to this user group to share with you an issue and the solution.

 

Situation :

-          Geoserver 2.12.3 (olders have been tested too with same observations)

-          A first layer is created to load a shape projected in 27572

-          A second one is created to load a raster projected in 2154

-          An agregation is created to mix these two layers, projected in 27572.

 

Problem :

-          The shape is not well placed on the raster, not very far but not good.

 

If I compare the definition of the projection and the projection on https://epsg.io/, I can see that there is some differences (parameters TOWGS84 is missing, some values are differents…).

I can then use epsg_overrides.properties to define the projection given in epsg.io.

Unfortunately, the result is worst.

 

After further try, I mixed the native parameters of 27572 known in GeoServer and official parameters given on epsg.io and obtain something good :

 

27572=PROJCS["NTF (Paris) / Lambert zone II",GEOGCS["NTF (Paris)",DATUM["Nouvelle_Triangulation_Francaise_Paris",SPHEROID["Clarke 1880 (IGN)",6378249.2,293.4660212936269,AUTHORITY["EPSG","7011"]],TOWGS84[-168,-60,320,0,0,0,0],AUTHORITY["EPSG","6807"]],PRIMEM["Paris", 2.5969213, AUTHORITY["EPSG","8903"]],UNIT["grade",0.015707963267948967],AXIS["Geodetic longitude", EAST],AXIS["Geodetic latitude", NORTH],AUTHORITY["EPSG","4807"]],PROJECTION["Lambert_Conformal_Conic_1SP", AUTHORITY["EPSG","9801"]],PARAMETER["central_meridian", 0.0],PARAMETER["latitude_of_origin", 52.0],PARAMETER["scale_factor", 0.99987742],PARAMETER["false_easting", 600000.0],PARAMETER["false_northing", 2200000.0],UNIT["m", 1.0],AXIS["Easting", EAST],AXIS["Northing", NORTH],AUTHORITY["EPSG","27572"]]

 

I hope it could help.

 

Clément

 

background

 

Clément Diot
__________
SYSTEL SA

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[hidden email]

Phone: +33 5 46 44 57 20

 

 

 



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- Earning your support instead of buying it, but Ian Turton: http://www.ianturton.com/talks/foss4g.html#/
- The GeoServer user list posting guidelines: http://geoserver.org/comm/userlist-guidelines.html

If you want to request a feature or an improvement, also see this: https://github.com/geoserver/geoserver/wiki/Successfully-requesting-and-integrating-new-features-and-improvements-in-GeoServer


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Re: Problem with on th efly projection between 27572 and 2154

jody.garnett
The is for the detailed research? Are you in position to make a big report (preferably with sample data attached as that is often frustrating to procure). 

On Thu, May 23, 2019 at 1:12 AM DIOT Clément <[hidden email]> wrote:

Hi all,

 

I just suscribed to this user group to share with you an issue and the solution.

 

Situation :

-          Geoserver 2.12.3 (olders have been tested too with same observations)

-          A first layer is created to load a shape projected in 27572

-          A second one is created to load a raster projected in 2154

-          An agregation is created to mix these two layers, projected in 27572.

 

Problem :

-          The shape is not well placed on the raster, not very far but not good.

 

If I compare the definition of the projection and the projection on https://epsg.io/, I can see that there is some differences (parameters TOWGS84 is missing, some values are differents…).

I can then use epsg_overrides.properties to define the projection given in epsg.io.

Unfortunately, the result is worst.

 

After further try, I mixed the native parameters of 27572 known in GeoServer and official parameters given on epsg.io and obtain something good :

 

27572=PROJCS["NTF (Paris) / Lambert zone II",GEOGCS["NTF (Paris)",DATUM["Nouvelle_Triangulation_Francaise_Paris",SPHEROID["Clarke 1880 (IGN)",6378249.2,293.4660212936269,AUTHORITY["EPSG","7011"]],TOWGS84[-168,-60,320,0,0,0,0],AUTHORITY["EPSG","6807"]],PRIMEM["Paris", 2.5969213, AUTHORITY["EPSG","8903"]],UNIT["grade",0.015707963267948967],AXIS["Geodetic longitude", EAST],AXIS["Geodetic latitude", NORTH],AUTHORITY["EPSG","4807"]],PROJECTION["Lambert_Conformal_Conic_1SP", AUTHORITY["EPSG","9801"]],PARAMETER["central_meridian", 0.0],PARAMETER["latitude_of_origin", 52.0],PARAMETER["scale_factor", 0.99987742],PARAMETER["false_easting", 600000.0],PARAMETER["false_northing", 2200000.0],UNIT["m", 1.0],AXIS["Easting", EAST],AXIS["Northing", NORTH],AUTHORITY["EPSG","27572"]]

 

I hope it could help.

 

Clément

 

background

 

Clément Diot
__________
SYSTEL SA

logo

[hidden email]

Phone: +33 5 46 44 57 20

 

 

 

_______________________________________________
Geoserver-users mailing list

Please make sure you read the following two resources before posting to this list:
- Earning your support instead of buying it, but Ian Turton: http://www.ianturton.com/talks/foss4g.html#/
- The GeoServer user list posting guidelines: http://geoserver.org/comm/userlist-guidelines.html

If you want to request a feature or an improvement, also see this: https://github.com/geoserver/geoserver/wiki/Successfully-requesting-and-integrating-new-features-and-improvements-in-GeoServer


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Jody Garnett


_______________________________________________
Geoserver-users mailing list

Please make sure you read the following two resources before posting to this list:
- Earning your support instead of buying it, but Ian Turton: http://www.ianturton.com/talks/foss4g.html#/
- The GeoServer user list posting guidelines: http://geoserver.org/comm/userlist-guidelines.html

If you want to request a feature or an improvement, also see this: https://github.com/geoserver/geoserver/wiki/Successfully-requesting-and-integrating-new-features-and-improvements-in-GeoServer


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Re: Problem with on th efly projection between 27572 and 2154

jody.garnett
I reported your issue to the geotools bug tracker: Accuracy issue reprojecting between EPSG:27572 and EPSG:2154

There are two troubles:
- This is an older version of GeoServer so I would like to ask you to test a newer version (preferably a nightly build). I am not sure the last time the EPSG database was updated.
- The bug report needs either some sample data to show the problem, or even a sample coordinates (So we can try out the transformation and show the problem, and then try out the fix and show that it is fixed).

Can you transform a test point please and let me know what the correct transformed coordinate is?

--
Jody Garnett


On Thu, 23 May 2019 at 09:49, Jody Garnett <[hidden email]> wrote:
The is for the detailed research? Are you in position to make a big report (preferably with sample data attached as that is often frustrating to procure). 

On Thu, May 23, 2019 at 1:12 AM DIOT Clément <[hidden email]> wrote:

Hi all,

 

I just suscribed to this user group to share with you an issue and the solution.

 

Situation :

-          Geoserver 2.12.3 (olders have been tested too with same observations)

-          A first layer is created to load a shape projected in 27572

-          A second one is created to load a raster projected in 2154

-          An agregation is created to mix these two layers, projected in 27572.

 

Problem :

-          The shape is not well placed on the raster, not very far but not good.

 

If I compare the definition of the projection and the projection on https://epsg.io/, I can see that there is some differences (parameters TOWGS84 is missing, some values are differents…).

I can then use epsg_overrides.properties to define the projection given in epsg.io.

Unfortunately, the result is worst.

 

After further try, I mixed the native parameters of 27572 known in GeoServer and official parameters given on epsg.io and obtain something good :

 

27572=PROJCS["NTF (Paris) / Lambert zone II",GEOGCS["NTF (Paris)",DATUM["Nouvelle_Triangulation_Francaise_Paris",SPHEROID["Clarke 1880 (IGN)",6378249.2,293.4660212936269,AUTHORITY["EPSG","7011"]],TOWGS84[-168,-60,320,0,0,0,0],AUTHORITY["EPSG","6807"]],PRIMEM["Paris", 2.5969213, AUTHORITY["EPSG","8903"]],UNIT["grade",0.015707963267948967],AXIS["Geodetic longitude", EAST],AXIS["Geodetic latitude", NORTH],AUTHORITY["EPSG","4807"]],PROJECTION["Lambert_Conformal_Conic_1SP", AUTHORITY["EPSG","9801"]],PARAMETER["central_meridian", 0.0],PARAMETER["latitude_of_origin", 52.0],PARAMETER["scale_factor", 0.99987742],PARAMETER["false_easting", 600000.0],PARAMETER["false_northing", 2200000.0],UNIT["m", 1.0],AXIS["Easting", EAST],AXIS["Northing", NORTH],AUTHORITY["EPSG","27572"]]

 

I hope it could help.

 

Clément

 

background

 

Clément Diot
__________
SYSTEL SA

logo

[hidden email]

Phone: +33 5 46 44 57 20

 

 

 

_______________________________________________
Geoserver-users mailing list

Please make sure you read the following two resources before posting to this list:
- Earning your support instead of buying it, but Ian Turton: http://www.ianturton.com/talks/foss4g.html#/
- The GeoServer user list posting guidelines: http://geoserver.org/comm/userlist-guidelines.html

If you want to request a feature or an improvement, also see this: https://github.com/geoserver/geoserver/wiki/Successfully-requesting-and-integrating-new-features-and-improvements-in-GeoServer


[hidden email]
https://lists.sourceforge.net/lists/listinfo/geoserver-users
--
--
Jody Garnett


_______________________________________________
Geoserver-users mailing list

Please make sure you read the following two resources before posting to this list:
- Earning your support instead of buying it, but Ian Turton: http://www.ianturton.com/talks/foss4g.html#/
- The GeoServer user list posting guidelines: http://geoserver.org/comm/userlist-guidelines.html

If you want to request a feature or an improvement, also see this: https://github.com/geoserver/geoserver/wiki/Successfully-requesting-and-integrating-new-features-and-improvements-in-GeoServer


[hidden email]
https://lists.sourceforge.net/lists/listinfo/geoserver-users