Libra

Overview

Libra is an open-source, Landsat-8 imagery browser. It relies on landsat-api and an AngularJS-designed GUI to allow users to browse, sort, and download more than 275 Terabytes of open Landsat imagery.

See here, here, and here for more information.

Setting up your development environment

To set up the development environment for this app, you'll need to install the following on your system:

• npm
• Compass & Sass
• Grunt ( $ npm install -g grunt-cli )
• Bower ($ npm install -g bower)

After these basic requirements are met, run the following commands in the root project folder:

$ npm install
$ bower install

Running the app

To start the app running, run the following command in the root project folder.

$ grunt serve

Serves the site at: http://localhost:9090 (should automatically open in your browser)

Deploying the app

To deploy the app, run the command below to create a dist directory in your project root

$ grunt build

dist is a directory of static HTML, CSS and JS files and can be served via any traditional web-serving mechanism.

Future improvements

• Determine a good way to show the total number of results being displayed
• Add animations where applicable
  • When switching into the single result pane
  • When the top filters drop down
• Make the scroll bar look a bit nicer
• Add a way to toggle between various basemaps
• Implement lazy loading for the results pane so not all images are loaded at the same time
• Place name search
• Different cluster sizes at different zoom levels
• Client side caching of results (TBD)
• Improved stack icons (2-3 circles for multiple results)

Known issues

• Histograms disappear when opening modal (close filters on modal open for now)
• Date filter clicks back one day when opening for the first time
• When over water where no scenes are returned, error message says '...you zoomed in too much' which isn't technically the exact error
• We currently have an issue when drawing the histograms where we get the dreaded Error: $digest already in progress in the console. While this doesn't cause any visual issues, it does mean we can't run the test suite.

Where to go from here?

Now that you have access to all this wonderful imagery, you may be wondering what do next. There are a number of open-source tools you can use to dive into the imagery on a deeper level. A few of them are listed below:

• landsat-util
• GDAL [Landsat-8 specific tutorial]
• QGIS [Tutorials]
• rasterio
• Mapbox guide