[PROJ] RD NAP + TRANS usage.

[David Fileccia]

Hi,
I am trying to get the transformations for the Netherlands using PROJ/GDAL and I just can't seem to get the "correct" answers based on the data I have been given. I have tried both the variant 1 and 2 of the nl_nsgi_*.tif files with no luck.

The following data was created using the EPSG:7415 transform and nl_nsgi_rdtrans2018.tif and nl_nsgi_naptrans2018.tif:
002_ETRS89.TXT                          002_RDNAP.TXT                          My Transform
point_id latitude  longitude height     x_coordinate  y_coordinate  height     x coordinate  y coordinate  height
-------- --------- --------- ---------- ------------- ------------- ---------- ------------- ------------- ----------
27494    55.812797 6.464483  425.168800 317878.638600 658759.794800 145.672100 222633.565431 870884.933093 383.755149
27495    55.299814 6.510675  470.791500 176752.325000 310861.303600 227.283900 226438.527368 813771.108781 429.897194
27496    51.280225 4.474798  244.634700 294571.817600 254007.429300  67.285500 91363.817760  366154.277735 199.958129
27497    52.182009 5.896621  230.874600 160485.457200 264354.757200  -4.823400 189874.491989 466218.873201 187.566647
27498    51.344185 7.195423   61.603000  13061.818100 821852.289400 -33.810100 281024.030900 374436.255812  15.291030
27499    53.651730 5.093408  451.380800 243523.431500 868519.454900 110.775700 135597.678988 629707.008204 410.362531


I am going from WGS84 lat/long/height to the RD coordinates. My transforms are as follows:
   // Create the SRS frames from the WKT
   OGRSpatialReference oSRC;
   oSRC.SetAxisMappingStrategy (OAMS_TRADITIONAL_GIS_ORDER);
   oSRC.SetWellKnownGeogCS ("WGS84");

   OGRSpatialReference oDST;
   oDST.SetAxisMappingStrategy (OAMS_TRADITIONAL_GIS_ORDER);
   oDST.importFromProj4 ("EPSG:7415");

   // Set the transformations
   m_g2r = OGRCreateCoordinateTransformation (&oSRC, &oDST);

===

Shift the source lat/long/height using the horizontal shift and the geoid.

===



   double x = lon;

   double y = lat;

   double z = height;



   // Perform the transformation from LLA to NEZ

   int ok = false;

   if (m_g2r) {

      ok = m_g2r->Transform (1, &x, &y, &z);

   }



   // If we fail then return failed results

   if (!ok) {

      x = 0;

      y = 0;

      z = BAD_VALUE;

   }

I have tried swapping lat/long and I have tried different transforms. I have even tried the variant 1 files with no luck. I think, the group that is having me look at this, has not given me all the information about the coordinate collection.

So, in summary:

  1.  Does anyone have any idea about what I am doing wrong?
  2.  Are there any known monuments with lat/long/height and the corresponding RD coordinates that I can check against?

Best Regards,

David Fileccia
Senior Systems Engineer | HEMISPHERE GNSS
Office: 6860 Little Twin Road, Germantown, OH 45327, USA
Corporate: 8515 E. Anderson Drive, Scottsdale, AZ 85255, USA
M: +1 404 579 4391
dfileccia at hgnss.com<mailto:dfileccia at hgnss.com> | www.hgnss.com<http://www.hgnss.com/>
[cid:image001.png at 01D7431D.5C411280]

Disclaimer: This message (including any other messages, attachments, or files within) contains information that may be confidential or privileged and is the property of Hemisphere GNSS, Inc. and its subsidiaries ('Hemisphere'). It is intended for the person to whom it is addressed. If you are not the intended recipient, you are not authorized to read, copy, distribute, print, retain, or use this message or any part thereof. If you receive this message in error, please notify the sender immediately and delete all copies of this message. Any opinions or views expressed within are solely those of the author and do not necessarily represent those of Hemisphere. Thank you for your cooperation.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/proj/attachments/20210507/0a8e442f/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.png
Type: image/png
Size: 5199 bytes
Desc: image001.png
URL: <http://lists.osgeo.org/pipermail/proj/attachments/20210507/0a8e442f/attachment-0001.png>