[OSM-talk] The long tail - lowest common denominator

[Petter Reinholdtsen]

[Lars Aronsson]
> The Landsat images are not perfect, of course, but they do show
> rivers and lakes in some greater detail than the VMap0 data.  Except
> where white clouds hide every detail (such as over Trondheim), and
> except where some other dark features appear (such as railroads),
> the dark blue is water and the rest is land.  Just filter out the
> dark blue, and you have a rough estimate of where the water is.
> Combine this rough estimate with the one given by VMap0, and you
> should be able to arrive at something better.

It is better to use other data sets from landsat when detecting water.
The visible light is not suitable, but near infrared combined with
other bandwiths make it very easy to detect water.

Detecting water using landsat images is a very common student task
when learning satellite image processing here at the university.

Google sent me to
<URL:http://academic.emporia.edu/aberjame/remote/landsat/landsat_proc.htm>
and
<URL:http://academic.emporia.edu/aberjame/remote/landsat/landsat_interp.htm>
when I searched on the topic.

Friendly,
-- 
Petter Reinholdtsen