Bug with GDAL and the Krovak map projection (could be PROJ4).

[arenol]

Description

I'm making a map of Norway using the Krovak map projection, a projection suitable for Banana-shaped countries like Czechoslovakia and Norway. I have some shape files projected using ArcGIS, and now I need to update the map, and I'm trying to use GDAL and QGIS to do the job (have GDAL 2.3).

Running gdalsrsinfo on a .prj-file from the old data in the target projection, reveals the following output:

PROJ.4 : +proj=krovak +lat_0=55 +lon_0=38 +alpha=0 +k=1 +x_0=15200000 +y_0=-14700000 +datum=WGS84 +units=m +no_defs
OGC WKT :
PROJCS["NorwegianKrovak",
GEOGCS["GCS_WGS_1984",
DATUM["WGS_1984",
SPHEROID["WGS_84",6378137.0,298.257223563]],
PRIMEM["Greenwich",0.0],
UNIT["Degree",0.0174532925199433]],
PROJECTION["Krovak"],
PARAMETER["False_Easting",15200000.0],
PARAMETER["False_Northing",-14700000.0],
PARAMETER["Pseudo_Standard_Parallel_1",74.0],
PARAMETER["Scale_Factor",1.0],
PARAMETER["Azimuth",0.0],
PARAMETER["Longitude_Of_Center",38.0],
PARAMETER["Latitude_Of_Center",55.0],
PARAMETER["X_Scale",-1.0],
PARAMETER["Y_Scale",1.0],
PARAMETER["XY_Plane_Rotation",115.0],
UNIT["Meter",1.0]]

However, using the PROJ-string above to project the updated data using QGIS or ogr2ogr, results in a map that is mirrored and rotated and also have other distortions. So something is definitely wrong.

See result here: https://www.dropbox.com/s/hog9scl4uqj9qf3/krovak_problem.png?dl=0

Steps to reproduce the problem.

You need sample files to reproduce this. Will provide this upon request.

Operating system

MacOS Mojave 10.14.1

GDAL version and provenance

2.3 (http://www.kyngchaos.com)

[rouault]

The mapping done from the ESRI WKT to the PROJ string is probably wrong. You may need to override it by adding a +axis=swu string to it. But the issue is more fundamental than this. Currently PROJ only supports pseudo_standard_parallel_1 == 78.5 and azimuth == 30.28813972222222 which are hardcoded values for the Czechoslovakia Krovak. Could you file an issue in https://github.com/OSGeo/proj.4/ about that ?

[rouault]

closing as a PROJ issue, not a GDAL one. OSGeo/PROJ#3907 might be related to that