October 24, 20205 yr On 23/10/2020 at 06:41, Moonshine said: For my own site I made a 3D surface of my existing site from the survey data. This has been really useful for working out areas and volumes of cut from the site. Thanks for mentioning LIDAR which I had never heard of before. I've had a look at the Government website and they mention that specialist software is needed to view the data. Is the data just coordinates and heights for DTM and how can you find the data for a specific area.
October 24, 20205 yr 1 hour ago, PeterStarck said: Thanks for mentioning LIDAR which I had never heard of before. I've had a look at the Government website and they mention that specialist software is needed to view the data. Is the data just coordinates and heights for DTM and how can you find the data for a specific area. The data is here https://environment.data.gov.uk/DefraDataDownload/?Mode=survey You can select tiles of data you want to look at. I use a GIS software called Qgis to look at the data as well process it and present it (amongst of data sets). The tile you download is a geo referenced tif file, which is a image. The colour of a pixel in the image represents the hieght at that point. You can use Qgis to export the image to 3D contour lines for use in other software.
October 27, 20205 yr @Moonshine I've had a go at this, not sure I've done it correctly though. I found the OS qrid square, marked out the area of interest using the polygon tool and downloaded the .tif file. When I view it as an image it's just white. I installed Qgis and viewed the file but it looks like it might be the whole OS grid square not just the area I marked out. I don't understand why there are white areas missing in the plot. Have I completely cocked it up.
October 27, 20205 yr Just now, PeterStarck said: @Moonshine I've had a go at this, not sure I've done it correctly though. I found the OS qrid square, marked out the area of interest using the polygon tool and downloaded the .tif file. When I view it as an image it's just white. I installed Qgis and viewed the file but it looks like it might be the whole OS grid square not just the area I marked out. I don't understand why there are white areas missing in the plot. Have I completely cocked it up. No, the white bits are where there is no data, nice one getting this far! What are looking to do with the data?
October 27, 20205 yr Just now, Moonshine said: What are looking to do with the data? I was hoping to produce a 3D image of the contours of the area of land I'm interested in, clipped to the actual site boundaries. I was then hoping to be able to view this in 3D spinning around. TBH that is the dream but just being able to view contours would be good. The land drops around 10m from one corner to the opposite diagonal corner and is terraced in two planes. When I tried to view the plot as contour lines it just showed one set of lines which looked like river channels which is why I wondered if it had given me data for the whole OS grid square.
October 27, 20205 yr 8 minutes ago, PeterStarck said: I was hoping to produce a 3D image of the contours of the area of land I'm interested in, clipped to the actual site boundaries. I was then hoping to be able to view this in 3D spinning around. TBH that is the dream but just being able to view contours would be good. The land drops around 10m from one corner to the opposite diagonal corner and is terraced in two planes. When I tried to view the plot as contour lines it just showed one set of lines which looked like river channels which is why I wondered if it had given me data for the whole OS grid square. It is possible, would take a bit of work to show you how, though I could probably do it in 10mins when I have spare time if you wanted. Let me know.
October 27, 20205 yr 21 minutes ago, Moonshine said: It is possible, would take a bit of work to show you how, though I could probably do it in 10mins when I have spare time if you wanted. Let me know. Can you set up a screen video capture, maybe with audio, then we can all see how to do it.
October 27, 20205 yr 4 minutes ago, SteamyTea said: Can you set up a screen video capture, maybe with audio, then we can all see how to do it. I'll see what I can do.
October 27, 20205 yr 38 minutes ago, Moonshine said: I'll see what I can do. Thank you. It will be a very useful resource.
October 27, 20205 yr Actually there are loads of tutorials already online, such as https://support.dronesmadeeasy.com/hc/en-us/articles/217759823-Using-QGIS-to-make-custom-Contour-Maps?mobile_site=true Google and other resources would be much better than anything I could put together.
October 28, 20205 yr On 24/10/2020 at 15:33, Moonshine said: You can use Qgis to export the image to 3D contour lines for use in other software. Been busy today so haven't been able to do much with the data today but just downloaded a simple DXF viewer that allows me to rotate the image. I'm getting there, thanks again.
October 29, 20205 yr Author I thought that was the Joy Division "Unknown Pleasures" album cover for a moment there!
October 29, 20205 yr 1 hour ago, Oxbow16 said: I thought that was the Joy Division "Unknown Pleasures" album cover for a moment there! Had to look that one up.
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