[PROJ] Is proj line associate to EPSG:31467 behaving properly?

[Kilian Demeulemeester]

Hi!

Our client is willing to generate his data in EPSG:31467 but he wants to 
translate +40cm on the y axis.

So I figured out that I would use the corresponding PROJ.4 "|+proj=tmerc 
+lat_0=0 +lon_0=9 +k=1 +x_0=3500000 +y_0=0 +ellps=bessel +units=m 
+no_defs +type=crs" |code and modify the y_0=0 with a y_0=0.4

1. Data are originally expressed in EPSG:4326

2. Using the EPSG code: via proj API, I transform the data via 
proj_create_crs_to_crs(..., "EPSG:4326", "EPSG:31497")

3. Now, if I replace the "EPSG:31467" with "|+proj=tmerc +lat_0=0 
+lon_0=9 +k=1 +x_0=3500000 +y_0=0 +ellps=bessel +units=m +no_defs 
+type=crs", (the corresponding proj line), the data are z-offsetted by 
approx 1000m
|

|I know that for some CRS, the PROJ.4 is not enough to generate the 
correct coordinates. Is that the case for this transformation?
|

|Ultimately, is there a something (+proj=pipeline ?) that I could use 
that would transform my data from EPSG:4326 to EPSG:31497 with a 
translation of +40cm on the y axis?|

|Thank you all!|

|Kilian
|




Kilian Demeulemeester
Software Project Lead - R&D

[https://yellowscan-lidar.com/]

525 Avenue Saint Sauveur du Pin
34980 Saint-Clément-De-Rivière - France
Tel: +33 (0)4 11 93 14 06
yellowscan-lidar.com [https://yellowscan-lidar.com/]
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/proj/attachments/20211201/abf1632d/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: x-disclaimer-534644925-0.png
Type: image/png
Size: 1125 bytes
Desc: x-disclaimer-534644925-0.png
URL: <http://lists.osgeo.org/pipermail/proj/attachments/20211201/abf1632d/attachment.png>