[PROJ] Sweref99 Cartesian

[Roger Oberholtzer]

We have been using proj to get Sweref99_tm (EPSG:3006) from WGS84
(EPSG:4326) values we collect from a GPS receiver. All is working
great.

We have had a request to provide Sweref99_tm Cartesian values. I have
looked at https://proj.org/operations/conversions/cart.html#cart but
I'm unclear how to do this in the context of Sweref99_tm.

If I don't use the EPSG codes, I get the expected Sweref99_tm values with:

proj +proj=tmerc +ellps=GRS80 +k=0.9996 +x_0=500000 +y_0=0 +lon_0=15.0
+lat_0=0.0

Would it just be changing +proj=tmerc to +proj=cart ?

I get values. But I don't know if they are correct.

echo 21.0000000000 69.0000000000 0.000 | proj +proj=tmerc +ellps=GRS80
+k=0.9996 +x_0=500000 +y_0=0 +lon_0=15.0 +lat_0=0.0
739639.19       7666089.70 0.000


echo 21.0000000000 69.0000000000 0.000 | proj +proj=cart +ellps=GRS80
+k=0.9996 +x_0=500000 +y_0=0 +lon_0=15.0 +lat_0=0.0
2279859.27      239622.87 0.000

Also, can this be done when specifying the EPSG:3006 code directly?


-- 
Roger Oberholtzer