Just a quick follow-up with some numbers for disk space usage for those
interested. I had a go at importing 10 metre contour lines for the whole
of Eurasia into PostGIS - latitudes of 0 - 46 degrees North required about
110 gig of disk space for the Postgres table and amounted to around 105
million contour lines. (I stopped it at this point before I ran out of
space :) - the SRTM3 data set extends up to 60 degrees North).
0-46N across Eurasia amounts to 3244 1x1 degree tiles. So this averages
you around 35MB of disk space to import a 1x1 degree tile into PostGIS
(obviously dependent on the terrain the tile covers), giving rough
estimated numbers of:
* Africa: 111 GB (3250 tiles)
* Australia: 36 GB (1060 tiles)
* Eurasia: 202 GB (5902 tiles)
* Islands: 5 GB (141 tiles)
* N America: 82 GB (2412 tiles)
* S America: 62 GB (1807 tiles)
* WHOLE WORLD: 498 GB (14572 tiles)
So with half a terabyte of disk you can import the whole lot... There is
also the higher resolution SRTM1 data set covering North America - I'm not
clear on how using those data would affect these numbers - probably not
much since you'll probably have roughly the same number of contour lines,
they will just be positioned more accurately.
- Steve
xmpp:[EMAIL PROTECTED] sip:[EMAIL PROTECTED] http://www.nexusuk.org/
Servatis a periculum, servatis a maleficum - Whisper, Evanescence
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