Dear list,
In July of last year I posted on geonetwork-users (http://sourceforge.net/p/geonetwork/mailman/message/34324442/) asking about how to customize the projection used in the GN3 map viewer. I work for the British Antarctic Survey, whose main focus of operation is the polar regions where we need to be using either Antarctic Polar Stereographic (EPSG:3031) or Arctic Polar Stereographic (EPSG:3995). The polar regions are clearly not well served by Google Maps/OSM Spherical Mercator EPSG:3857 due to extreme distortion.
Back in July I received a lot of helpful hints from Florent Gravin, and got a certain amount of the way. I certainly have been able to create a new map context document using our particular set of Antarctic services, and have got GN to the point of recognising the custom projection. I downloaded and built the current GN 3.1 from GitHub, and made some changes to several JavaScript files. Working with the installation in debug mode, I was able to see the effects of my changes. From this, and from my reading of the code with my limited experience, it does look like the assumption that Spherical Mercator EPSG:3857 will be used for all maps is quite firmly embedded. The OL map creation code even adds an ol.source.OSM() layer which ties the map in to OSM's projection.
I have spent several days basically hacking to see where I got to, and have come to the conclusion that I don't have enough familiarity with the code's operation to confidently make the changes we need. I could spend a large amount of time coming up with a poor solution which we would then have to keep back-porting into new versions of GN, not a route we want to take.
I wonder therefore, and that's why I'm posting here on the devel list, whether we as an organisation could pay one of the GN core developers to implement the feature we want, namely to have the ability that all GN maps can use any projection supplied by the administrator (and particularly Polar Stereographic ones)? I'm not sure how we would enter into negotiations about this? I am aware that CampToCamp offer training in GN development, and potentially offer paid development support. I'm not clear whether they can offer paid for development of new features? If this is something any of the core developers would be interested in, please get in touch with me and give an estimate of the likely cost and timeframe.
Also, if the requirements need more clarification, I would be happy to discuss further.
Best wishes,
David Herbert
Web GIS Developer
British Antarctic Survey.
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