[OSM-talk] SRTM contours on Mapnik map

[Nick Black]

Yes - I really dont think there is any point at all in including
contours in the MySQL DB.  They should be kept in PostGIS, to use for
rendering or other spatial stuff.

The SRTM has relative and absolute height errors less than 10m
globally [1].  However, this it is only released with a 90m postings -
the NDA downgraded the data they released for everywhere other than
the continental USA.  There are various clever ways of interpolating
between the postings to derive reliable data.  There PERS edition
below [1] has some interesting articles, and is basically
everyhing-you-are-ever-likely-to-find-out about the SRTM.  Try some
searches on google scholar and you can find most of the papers for
free.

[1] http://www.asprs.org/publications/pers/2006journal/march/abstracts.html



On 1/20/07, Dean Earley <dean at earlsoft.co.uk> wrote:
> Nick Whitelegg wrote:
> > On Friday 19 Jan 2007 21:29, SteveC wrote:
> >> this and the flight paths make a strong case for a sister project -
> >> perhaps doing some mass altitude analysis of the gps data we've
> >> built up.
> >
> > Would this be more accurate than SRTM though? IMX the altitude
> > readings on GPS devices are less accurate than SRTM.
>
> Seeing as my bedroom window fluctuates by about 90'.... :)
>
> --
> Dean Earley, Dee (dean at earlsoft.co.uk)
>
> irc:    irc://irc.blitzed.org/
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>
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-- 
Nick Black
--------------------------------
http://www.blacksworld.net