[HOT] Satellite image quality too low for mapping / not loading

Dan Marsh danrok.giga at gmail.com
Wed Apr 29 17:13:29 UTC 2015

If you are using the JOSM editor, I can highly recommend this plug-in:

It allows you to trace simple rectangular buildings much faster.

On 29 April 2015 at 12:35, Max Bainrot <mbainrot at gmail.com> wrote:

> I am quite new too (having done only 1 quarter tile before for South Sudan
> Ebola crisis and a little bit of mapping in my local area) and I can relate
> to your frustration, what further compounds things is the countries
> cultures, building style, etc can and often are different to that of where
> you live/have experienced
> What I do when I have a hard time identifying features is zoom in and out,
> usually that helps with the low resolution and sometimes the stitching
> obscures things on one zoom level but goes away on a different zoom level
> Usually you can see a contrast that forms an X or a line in the center
> which is the roof capping and that's a pretty good give away
> Another one depending on the imagery is shadows, they give you a really
> good idea of what a given structure is and how high it is (thus helping you
> decide if its a short wall/hedge or a proper fence)
> Also try cycling between different imagery and that can help identify
> structures due to different times of day captures, etc
> When I was helping out with the Sudan Ebola outbreak I found it a lot
> easier to cycle between bing and the other imagery (my memory is bad
> sorry), one was quite bright but low res the other was higher res but alot
> darker with longer shadows, between the two it helped me identify what
> looked like small buildings to be vans as well as highlight buildings that
> weren't visible in the other imagery
> Another thing that helps you learn is in your editor (I use JOSM, not very
> beginner friendly but it's worth it IMHO) is to toggle your DATA layer (the
> layer all the polygons are on) that'll make it easier to see whats beneath
> other peoples work and help you learn what buildings, carports, outdoor
> toilets/wells look like on the sat photos/aeriel photographs
> After a short time you'll get to know certain ground features (random dirt
> clearings, weird bright reflections, etc) that give away that there is a
> structure there/nearby and it'll make things easier.
> Cheers,
> Max
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Dan Marsh
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