[Proj] Correction of definition of CRS EPSG 5456 and 5457

[Andre Joost]

Hi Eduardo,

The EPSG projection definitions in PROJ.4 are always taken from the 
official EPSG database https://www.epsg-registry.org/ , so you have to 
address your issue there firstly, adding some kind of official sources.

Note that datum shifts are treated separately in the EPSG database, so 
you have to divide your problem into:

a) different lat1/lat2 values

b) different towgs84 values.

Regarding the lat1/lat2 issue, see also

https://gis.stackexchange.com/questions/253475/results-of-layers-created-with-a-custom-crs-are-loaded-with-a-generated-crs-in-q/254087#254087

HTH,
Andre Joost

Am 21.01.18 um 04:01 schrieb Eduardo Rojas Rodríguez:
> Greetings to all
>
> let me introduce myself, my name is Eduardo Rojas Rodríguez I am a
> Geographer specialized in GIS, I live in Costa Rica and I work for SOLTIG
> who are the official commercial support of QGIS in Costa Rica.
>
> Personally I am a fan of all OSGeo projects and I am currently very
> committed to QGIS, all OSGeo projects and free software, I am given the task
> to better understand the project of PROJ4 and how it works.
>
> For this reason I realized that there is a problem with the definition that
> is currently in PROJ4 for CRS
> EPSG 5456 and EPSG 5457 (Lambert Ocotepeque 1935 / Costa Rica North and
> Lambert Ocotepeque 1935 / Costa Rica South).
>
> The current definitions are:
>
> EPSG 5456 current definition in PROJ4: (incorrect)
> +proj=lcc +lat_1=10.46666666666667 +lat_0=10.46666666666667
> +lon_0=-84.33333333333333 +k_0=0.99995696 +x_0=500000 +y_0=271820.522
> +ellps=clrk66 +towgs84=205,96,-98,0,0,0,0 +units=m +no_defs
>
> EPSG 5457 current definition in PROJ4: (incorrect)
> +proj=lcc +lat_1=9 +lat_0=9 +lon_0=-83.66666666666667 +k_0=0.99995696
> +x_0=500000 +y_0=327987.436 +ellps=clrk66 +towgs84=205,96,-98,0,0,0,0
> +units=m +no_defs
>
> After investigating the correct definition of CRS 5456 and 5457 and its
> definition in PROJ4
> should be replaced by:
>
> EPSG 5456: Ocotepeque 1935 / Costa Rica Norte (correct definition)
> +proj=lcc +lat_0=10.46666666666667  +lat_1=9.933333333 +lat_2=11
> +lon_0=-84.3333333333 +k_0=0.99995696 +x_0=500000 +y_0=271820.522
> +ellps=clrk66 +towgs84=213.116,9.358,-74.946,1.140,-2.980,3.100,-5.22
> +units=m +no_defs
>
> EPSG: 5457: Ocotepeque 1935 / Costa Rica Sur (correct definition)
> +proj=lcc +lat_0=9 +lat_1=8.4666666667+lat_2=9.533333333
> +lon_0=-83.666666667 +k_0=0.99995696 +x_0=500000 +y_0=327987.436
> +ellps=clrk66 +towgs84=213.116,9.358,-74.946,1.140,-2.980,3.100,-5.22
> +units=m +no_defs
>
> with these definitions, the transformations that depend on the PROJ4 library
> should be correct.
>
> If you can help me explaining how and where to generate the report to
> request the change of the definition, I thank you.
>
> Is it just generating the report at https://github.com/OSGeo/proj.4/issues?
>
> Thank you very much for the help
>
>
>
>
>
>
>
>
> -----
> Eduardo Rojas Rodríguez
> Analista en SIG
> Soluciones en Tecnologías
> Tel: 506 2505-5453
> eduardo.rojas at soltig.net
> http://soltig.net
>
>
> --
> Sent from: http://osgeo-org.1560.x6.nabble.com/PROJ-4-f3840930.html
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