Mercator settings from .PRJ

[tjhb]

Mike,

I shouldn't really call this a bug, since .PRJ files are inevitably approximate.

The issue is that for Mercator projections, GM 12.01 (and previous versions) overlooks the True Scale Latitude parameter written in a PRJ file (for some reason) as standard_parallel_1. It always defaults to 0.

This is the case even for .PRJ files GM has written itself.

[global_mapper]

I would expect GM to write the true scale latitude to a parameter named 'latitude_of_origin' (seems to be the standard one used although really seems like the wrong one). In any case, I have updated the PRJ importer to recognize 'standard_parallel_1' for the True Scale Latitude parameter. I have placed a new build at http://www.globalmapper.com/global_mapper12.zip with the change for you to try. Simply download that file and extract the contents into your existing v12.xx installation folder to give it a try. If you are using the 64-bit v12 version there is a new build at http://www.globalmapper.com/global_mapper12_64bit.zip .

Let me know if I can be of further assistance.

Thanks,

Mike
Global Mapper Support
support@globalmapper.com

[tjhb]

Mike,

For the files we were having difficulty with, the true scale latitude is now recognised effortlessly and correctly.

Thank you very much.

Tim