[mkgmap-dev] Flooding in Southern Scotland

Sun Jan 1 20:33:58 GMT 2012

On Sun, Jan 01, 2012 at 02:00:17PM +0000, Roger Calvert wrote:
>mkgmap came up with many errors relating to 'anti-islands' - I suspect 
>these are round Scotland, and I'll leave it to local people to sort  
>them out!

An anti-island is normally easy to sort out. You would simply reverse 
the nodes of the way so that land would be on the left side of the way.  
If aerial image shows that it is not an island, but a small pond of 
water, then you should use something else for it, such as natural=water 
or landuse=reservoir.

Other types of coastline errors can be more tricky. Last November, it 
took me several iterations to fix the coastline west of Helsinki when a 
beginner had deleted sections of coastline in the archipelago and 
redrawn it from high-resolution Bing images. Both JOSM and me failed to 
notice that he had reversed some of the mainland coastline ways. After 
fixing all islands, it still kept flooding, and I finally noticed it.  
Currently, the coastline validator in JOSM should detect this.

>I think I'll leave this to someone with a bigger computer and more time 
>and expertise. At present, I am not a JOSM or OSMOSIS user.

OK. I cannot call myself an advanced Osmosis user either. It is a 
complex 'Swiss army knife' type of tool, but there are some examples in 
the documentation 
http://wiki.openstreetmap.org/wiki/Osmosis/Detailed_Usage

JOSM might be a bit different matter. It could require some more 
learning, but IMO it is worth it. I have been using it for 3 years now, 
since the beginning of my involvement with OSM.

Best regards,

	Marko