[MapServer-users] Trying to get the right transformation with Mapserver 8.0.0 + PROJ 9.1.0

[Jeff McKenna]

Hi Wouter, when I get stuck like this, the first thing I do is compile 
'master' of PROJ, GDAL, and also MapServer, and then re-try.  Once that 
fails then I know I'm officially stuck :)

-jeff




-- 
Jeff McKenna
GatewayGeo: Developers of MS4W, MapServer Consulting and Training
co-founder of FOSS4G
http://gatewaygeo.com/



On 2022-11-08 9:43 a.m., Wouter Visscher wrote:
> Hi,
> 
> I'm struggling a bit with Mapserver (8.0.0) + PROJ (9.1.0) getting it to 
> use the right transformation (RDTRANS2018) rules.
> 
> I have a (Docker) environment with
> - PROJ 9.1.0
> - GDAL 3.5.2
> - Mapserver 8.0.0 (branch-8-0)
> 
> When I run cs2cs (PROJ) the output is correct (in order words what I 
> expect) going from EPSG:28992 -> EPSG:4258.
> With PROJ_DEBUG on I can verify that is calling the right tif 
> (nl_nsgi_rdtrans2018.tif in this case)
> Moving up the chain by using GDAL (ogr2ogr GPKG EPSG:28992 -> GPKG 
> EPSG:4258) I get the same correct result.
> 
> But putting it all together with Mapserver I'm not seeing the same 
> result and I'm getting results +100m from where they should be.
> The strange thing is when I use EPSG:25831 (ETRS89 / UTM zone 31N, in 
> meters) instead of EPSG:4258 (ETRS89, degree) the results are correctly 
> translated. (also using the nl_nsgi_rdtrans2018.tif when called with cs2cs)
> 
> Mapserver also seems to use the correct PROJ 9.1.0, when I alter 
> PROJ_DATA or remove the proj.db it says it's missing them.
> Also using different data sources like GPKG, FGB, and so on doesn't seem 
> to change this behaviour.
> 
> Does anyone know what could be causing this or advice on how to further 
> investigate the issue?
> 
> Regards,
> Wouter
> 
>