| Happy Trails 2008-01-16, 10:33 am |
| On Wed, 16 Jan 2008 06:20:23 GMT, Gerry Snyder
<mesmerizerfan@gmail.com> wrote:
Gerry
It's late evening, and I'm sitting in my hacienda in Southern
Philippines with a nice cool breeze blowing in from the balcony, and
FA else to do. Way too much time on my hands.
If it does turn out there is no data below zero, try this. Get an
outline of the sea shoreline, and assign it an elevation of -66 feet,
or whatever wikipedia says is the current elevation. Get another
polygon - the first non-zero contour going away from the lake - it's
close enough to work. Then use your software to interpolate the
contours in between. Considering the way the lake has formed over the
millenia, it'll be very close to the truth. Be careful the 2 meter
bump over by the gravel pit (or any other) doesn't trick you. Your
results will be incorrect in the odd case where the elevation goes
back below zero again after rising above zero going away from the
lake, but I think that bump is the only place where that happens.
If you aren't able to do this with your sw, send me your lake outline
and the elevation data file you do have, and I'll do it for you
tomorrow night. I am pretty handy with a very good 3D land modelling
package, and I've just been doing a bunch of this kind of stuff with
..hgt files of Mindanao data. Nothing below zero though - it's a new
challenge!
- Tom
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