Thank you, Ian (and Peter).
I had actually considered using gdal_merge.py to combine the GeoTiffs I'd
created, but thought the resulting mega-TIFF would be too large. However:
gdal_merge.py -o elevation.tif -co BIGTIFF=YES -co TILED=YES -co
COMPRESS=DEFLATE *.hgt.tif
worked fine. GeoServer accepted this store and maps it slowly, but without
generating errors.
For reference, the resulting TIFF, elevation.tif is just over 100
gigabytes in size, and has a resolution of 1296001 x 417601, which is
slightly less than I expected because it turns out SRTM1 doesn't cover the
entire world.
On Tue, 21 May 2019, Ian Turton wrote:
Date: Tue, 21 May 2019 08:18:23 +0100
From: Ian Turton <[email protected]>
To: Barry Carter <[email protected]>
Cc: geoserver-users <[email protected]>
Subject: Re: [Geoserver-users] Serving SRTM1 data with GeoServer
Have a look at https://www.ianturton.com/tutorials/bluemarble.html where I
have example scripts and work flow to create a base image from a set of
tiles and how to make a pyramid from it.
Ian
On Tue, 21 May 2019 at 03:16, Barry Carter <[email protected]>
wrote:
I'm trying to provide SRTM1 (1 arcsecond resolution elevation) images and
data
using GeoServer, but can't figure out how to serve such a large dataset
efficiently. Here's what I've done so far:
- Downloaded the 1 degree squared HGT files. The Earth is 360*180 =
64800
square degrees, but only 14295 HGT files since the other square
degrees
are 100% water. The HGT files are uncompressed and 25,934,402 bytes
each.
- I then used commands like:
gdal_translate -co TILED=YES -co COMPRESS=DEFLATE N58W122.hgt
N58W122.hgt.tif
to convert these HGT files into TIFFs. The TIFFs vary in size, but are much
smaller.
- I then imported the directory with the TIFFs as a store using
ImageMosaic. This took a while, but appears to have worked, since
"srtm1"
(the name I gave it) now appears in my list of stores.
- I then created a layer using this source, but when I use "OpenLayers"
preview, the server hangs for a while and ultimately dies with "too
many
open files" (or similar). This seems odd, since my Linux OS had
fs.file-max set to 13063650. I even tried doubling it to 26127300, but
that didn't help.
At this point, I suspect I need to create an image pyramid or something so
GeoServer can handle the data efficiently, but I'm not sure exactly what to
do. I've used 'gdal_retile.py' previously to create pyramids from one large
image into tiles at various zoom levels, but I think I want to do the
opposite
here (merge smaller images for lower zoom levels). The gdal_retile.py
option
-pyramidsonly seems to say it does that, but I can't get it work (it just
hangs and creates no files)
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- Earning your support instead of buying it, but Ian Turton:
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http://geoserver.org/comm/userlist-guidelines.html
If you want to request a feature or an improvement, also see this:
https://github.com/geoserver/geoserver/wiki/Successfully-requesting-and-integrating-new-features-and-improvements-in-GeoServer
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--
Ian Turton
_______________________________________________
Geoserver-users mailing list
Please make sure you read the following two resources before posting to this
list:
- Earning your support instead of buying it, but Ian Turton:
http://www.ianturton.com/talks/foss4g.html#/
- The GeoServer user list posting guidelines:
http://geoserver.org/comm/userlist-guidelines.html
If you want to request a feature or an improvement, also see this:
https://github.com/geoserver/geoserver/wiki/Successfully-requesting-and-integrating-new-features-and-improvements-in-GeoServer
[email protected]
https://lists.sourceforge.net/lists/listinfo/geoserver-users
