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<div class="moz-cite-prefix">Hi Michael,<br>
<br>
Off the top of my head, but have you looked into a laser scanner
mounted on some sort of aerial platform such as a cherry picker?
Not sure whether the platform would be stable enough.<br>
<br>
Alternatively a low level UAV flight may provide a detailed enough
DTM through stereo imagery analysis.<br>
<br>
Cheers,<br>
<br>
Andy<br>
<br>
On 18/09/2014 10:43, Michael.Dodd wrote:<br>
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<div style="direction: ltr;font-family: Tahoma;color:
#000000;font-size: 10pt;">Any suggestions as to the best way to
survey and interpolate ridge and furrow grassland that is not on
a flat plane?<br>
I have tried various methods without success.<br>
<br>
The ridge and furrow area that I want to map is about 120mx120m,
the ridge and furrow pattern is distinct with about 0.5m or
difference between ridge ht and furrow base but the pattern has
a slight curve towards one end and the land is not flat. If you
are not sure what ridge and furrow looks like then there is an
example at 51.9827, -0.9135, the stripes are clearly visible on
the google earth image.<br>
<br>
Mapping can be done with cm level dgps but does this require
many tens of thousands of points to be recorded. Or can fewer
points be recorded and qgis interpolation somehow be told to
interpolate along the ridge and furrow then fill in the area
between them with some sort of curve. The actual curve is also
problematic as the ridge top tends to be flattened and not a
smooth sine wave. I don't have good LIDAR of the area but even
that resolution may not be good enough.<br>
<br>
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<br>
<pre class="moz-signature" cols="72">--
Andy Harfoot
GeoData Institute
University of Southampton
Southampton
SO17 1BJ
Tel: +44 (0)23 8059 2719
Fax: +44 (0)23 8059 2849
<a class="moz-txt-link-abbreviated" href="http://www.geodata.soton.ac.uk">www.geodata.soton.ac.uk</a>
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