The Swedish Geodetic Agency Lantmateriet provides a document (see references) with a procedure for transforming coordinates between ITRF2014 and SWEREF99. The document also provides and example of the transformation.
I am attempting to perform the transformation using cct from proj.org since the document alludes to it being the documented method of doing so. There is a partial example of using it here, but it does not include a change of epoch.
In the document, there is an example transform in geocentric coordinates:
Initial ITRF2014 coordinates (epoch 2020.25) of the example stations 2251700.0000 819600.0000 5891200.0000 The coordinates of the example stations in SWEREF 99 (epoch 1999.5). 2251700.5587 819599.6862 5891199.6467
How do I reproduce these results using
The previously mentioned method was:
echo 2251700.0000 819600.0000 5891200.0000 2020.25 | cct NKG:ITRF2014_TO_SE
Which emits coordinates for the same epoch (2020.25):
2251700.5587 819599.6862 5891199.6467 2020.2500
How does one change the epoch to 1999.5 to match SWEREF99 example?
+t_epoch=1999.5 does not seem to help.
dusha@computer:~$ echo 3468700.0000 864800.0000 5264500.0000 2020.25 | cct +t_epoch=1999.5 NKG:ITRF2014_TO_SE proj_create: unrecognized format / unknown name cct: Bad transformation arguments - (Invalid PROJ string syntax) 'cct -h' for help
I am running a recent release from Debian:
dusha@computer:~$ cct --version cct: Rel. 9.1.0, September 1st, 2022
- Lantmateriet, "Transformation between ITRF 2014/WGS 84 and SWEREF 99", 2021-03-12.