OSTN15 Transform

[Jonathan3]

Hi,

I have been asked if we are using the OSTN15 transform when reprojecting from OSGB to WGS84. I am unsure how to get to that level of detail on how the ThinkGeo code works. We do set up a reproject like:

            ProjectionConverter projConverter = new ProjectionConverter()
            {
                InternalProjection = new Projection(ProjectionHelper.OSGBProjectionString),
                ExternalProjection = new Projection(4326)
            };

And I believe (maybe wrongly?) that you use GDAL libraries for the transforms?

Can you help me further on this at all?

Regards,
Jonathan

[Ben]

Hi Jonathan,

1. ProjectionConverter is a managed C# class.
2. You can download NuGet Gallery | ThinkGeo.UnmanagedProj 14.1.2 and use the class of UnmanagedProjectionConverter in it, which is using proj4 and gdal 2.4.4
3. We recently updated the beta ThinkGeo.Gdal package to use the latest gdal 3.9.1. You can use the class of GdalProjectionConverter in it and take advantage of the latest gdal. We will soon have a new release with this upgrade. We recently have a Projection related question with a sample in it, please have a look if you are interested. Projection issue with ProjectionConverter and UnmanagedProjectionConverter for latest EPSG code

Thanks,
Ben