This repo contains a minimal demo site to accompany the PHP class OSTerrain50Reader.php which returns elevation data for Great Britain. It reads a custom binary data file containing elevation data compiled from the freely-downloadable OS Terrain 50 ASCII data set.
The binary data file is produced from a free data-compiling application which is available to download from a sister repo OSTerrain50-SimpleBinary - more details there. Direct download links are also available below.
OS Terrain 50 data is almost certainly the optimal free data set to use for the generation of elevation data for Great Britain. The reasons why are explained in more detail on the author's site. The reader code produces thousand of elevations in millseconds and is an easy way to obtain elevation data without using specialist GIS software.
You can see a working version of this demo on the author's site.
In order to run it yourself you will need a webserver with PHP 7.4 or higher. Here's how:
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git clone (or download) this repo's files to your webserver
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download the
ASCII Grid & GML (Grid)OS Terrain 50 ASCII data zip file -
download the command-line data compiler application
osterrain50, available as:- a signed & notarized Mac Universal Binary 64 bit DMG file
- a Windows 64 bit zip file
- a Ubuntu 64 bit tar.gz file
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use the application to unzip and convert the downloaded OS data zip file into a binary data file thus:
$ ./osterrain50 path/to/downloaded_OS_data_zip_file -
place the generated binary data file
OSTerrrain50.binin the same directory as the site files (the OS data zip and data files can now be discarded) -
browse to the site
The reader class is heavily commented to assist with translation to other languages. The sister Rust repo also contains working demo code to read the binary data file to produce elevation data.