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LIDAR Composite DTM: please provide a DTM-10m for download of whole England

Hi!

Right now it's not possbile to download the complete LIDAR Composite DTM data of England, due to the large file sizes (about 60 GB for DTM-2m). People have to send you HDDs which is time consuming, unnecessarily extra work for the people as well as for you and also linked to extra costs for postal charges. So my request:

Please additionally provide a DTM-10m version of your Composite DTM of all your total surveyed area of England. Ideal packed into one .zip file, so no need to individually select hundreds of squares onto the map first like with DTM-1m or DTM-2m.

Many other international countries' surveying institutes provide their DTMs in a horizontal resolution of 10 meter. This is still a quite detailled grid for most of the user cases, and on the other hand saving a lot of (for the user cases unneeded) file size. Your complete LIDAR-DTM data would be sized around 2 GB as DTM-10m, which is an acceptable size to download. You maybe could save even more filesize if providing the data not as zipped .asc files but for example as GeoTIFFs which is a very popular format for DTMs too.

PeterS //

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Hi Peter 

Thank you for your comments, as it stands the DTM-10m version data isn't available to download directly from the DSP, but we can arrange an offline supply via a download link. 

I will contact you directly directly with the link. 

Many thanks

Ella Fotheringham

Environment Agency 

Ella Fotheringham 0 votes //
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Hi Ella,

Thanks a lot for the download of the DTM-10m. A very high quality terrrain model.

For the records, if you're going to create a new version of the DTM-10 in the future there're 2 ideas to decrease its filesize:

1) right now the vertical resolution is 1 millimeter. You could round the values to 1 decimeter, which is stilll enough precision for almost every user case. for example an elevation of 534.841 m would become 534.8 m
2) besides the DTM itself (.tif), there's another big file (.tif.ovr) - which is just the image pyramide of the DTM. I think you can leave it, this is usualy not needed - if some people need this additional image pyramide, they could create it themselves after they downloaded the .tif.

Both points reduce the filesize significantly to just 36 % of the filesize right now.

PeterS 0 votes //
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Hi Ella,

I too would be interested in obtaining a copy your 10m DTM data, would this be possible?

 

Best wishes,

Nick, 

Nick Hopton 0 votes //
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Good morning Nick, 

No problem, I will send you the link directly.

Many thanks

Ella Fotheringham

Environment Agency

Ella Fotheringham 1 vote //
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Hi Ella and Peter,

First off, many thanks for the 10m terrain data, which will be very useful to me.

I use Ubuntu Linux and had problems unzipping the archive using the Ubuntu Archive Manager, but I then installed 7zip which worked without problems.

Obviously there are still quite a few holes in the data and I wonder when these are likely to be filled?

I agree with the previous comment about the *.tif.ovr layer. 

Best wishes,
Nick.     

 

Nick Hopton 0 votes //
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Hello Ella,

I, too, would very much like to have a copy of this dataset.

Thank you

Robert

Robert Brown 0 votes //
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