Terrain Elevation for Real Locations

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martink
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Terrain Elevation for Real Locations

Post by martink »

Making a flat model with lots of buildings presents one set of challenges; making a reasonably accurate model of open and hilly country (e.g. Blea Moor) presents another set entirely.

There is a UK government website that has free-to-download aerial LIDAR (laser-radar) elevation data for much of the country, at 1m and 2m resolutions. The files are in a simple text format, so can be easily read and processed by suitable software. For a quick feasibility study, I simply downloaded some into Excel and plotted that as a surface chart, and was very impressed by the results. So, it looks like I will have to write some custom software to convert this into something that can be used directly.

I'll post more on this when I've written the software and improved the techniques.

FWIW, the data for Ribblehead is at https://environment.data.gov.uk/ds/surv ... ?grid=SD77

And here is a sample Excel plot showing the Blea Moor end of the Ribblehead viaduct at 2m resolution. It even shows the stone walling and footpaths!
rh-lidar1.jpg
rh-lidar1.jpg (159.64 KiB) Viewed 2959 times

martink
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Joined: Sun Feb 09, 2014 3:13 am
Location: Melbourne, Australia
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Re: Terrain Elevation for Real Locations

Post by martink »

Doing some more experiments on this, working towards a tool to help with building the track beds, making cutout elevation profiles as supports for the scenery, and 3d printed full-terrain models. The next addition is superimposing the baseboards.

The Ribblehead / Blea Moor area, flattened to remove the 1 in 100 gradient, with 5m contours (10mm on the model)...
test1.jpg
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For a bit of contrast, just to the west of Plymouth, with 10m (20mm) contours and no adjustments...
test2.jpg
test2.jpg (429.19 KiB) Viewed 532 times

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dkightley
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Location: Nottingham, UK

Re: Terrain Elevation for Real Locations

Post by dkightley »

I recognise that last image!! ;) ;)

And the website you've quoted is where I got the data from when I wanted to sort out contours for The Bridges at Saltash. But I'can't fully remember exactly how I processed the data....but I did end up with 5m contour lines overlaid onto a Google Earth image:
Capture1.PNG
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At scale size, 5m works out at 11.1 mm...which is quite easy to gauge if you work with insulation foam as a ground material. I have some cheap vernier callipers that have a piece of wire as a depth gauge, and simply pierce the wire into the foam to measure the depth.
Doug Kightley
Webmaster here and volunteer at the National Tramway Museum http://www.tramway.co.uk

martink
Posts: 268
Joined: Sun Feb 09, 2014 3:13 am
Location: Melbourne, Australia
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Re: Terrain Elevation for Real Locations

Post by martink »

After another few hours fiddling, all still in rough form, but getting close to usable.

Ready to 3d print...
test43d.jpg
test43d.jpg (98.01 KiB) Viewed 2866 times
Cutout diagrams for foam sheets at selected elevations/contours with a 300mm grid...
test5.jpg
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Clipping to the actual baseboards (the bottom one is deliberately distorted to compensate for some compression)...
test4.jpg
test4.jpg (133.96 KiB) Viewed 2866 times

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