terrain50

Library for parsing Ordnance Survey Digital Elevation Model files

I'm handing a number of different Ordnance Survey Digital Elevation Model files (in the ASCII Esri Grid format as far as I understand) as part of my PhD. This library is the result of the surprisingly extensive code I wrote to handle them.

While it's a relatively simple format to understand, it's completely terrible for disk space usage:

ncols 2400
nrows 4000
xllcorner 550000
yllcorner 220000
cellsize 50
NODATA_value -9999
86 77 76 79 (.....)

This package makes it bearable. See also terrain50-cli, the command-line interface for this library.

• Current version:
• API Docs: https://starbeamrainbowlabs.com/code/terrain50/
• Changelog: https://github.com/sbrl/terrain50/blob/master/Changelog.md

Install

Install via npm:

npm install terrain50 --save

Usage

The full API documentation can be found here: https://starbeamrainbowlabs.com/code/terrain50/

Basic usage:

import fs from 'fs';
import Terrain50 from 'terrain50';

(async () => {
    "use strict";
    
    let new_instance = Terrain50.Parse(
        fs.readFileSync("path/to/file.asc", "utf-8")
    );
    
    new_instance.scale(2);
    let output = fs.createWriteStream("path/to/output.asc");
    await my_instance.serialise(output);
})();

Read-world use

• I'm using it for the main Node.js application for my PhD in Computer Science!
• (Are you using this project? Get in touch by opening an issue)

Contributing

Contributions are welcome as PRs! Don't forget to say that you donate your contribution under the Mozilla Public License 2.0 in your PR comment.

Licence

This project is licensed under the Mozilla Public License 2.0. See the LICENSE file in this repository for the full text.