Mapbox’s Landsat-live project: Maps with the most up-to-date Satellite imagery

By Muthukumar Kumar



The Landsat program from USGS/NASA is certainly the most iconic Earth Observation program ever. Not only does it provide the longest continuous space-based record of Earth but the Landsat program also democratized access to satellite imagery, enabling researchers across the world to use latest satellite imagery for various Remote sensing and GIS studies. (Read more: Landsat 8 Captures dramatic details of the Earth; will push the Earth – Monitoring Envelope).

Although Landsat satellite imagery have been available for the public for a while now, we haven’t had a project that can be considered as the OpenSatelliteImagery project, well until now. Mapbox has changed that with Landsat-live, a geoawesome project that utilizes the latest Landsat 8 data is publicly available on Amazon Web Service via the Landsat on AWS Public Data Set.

Chicago March 11, 2015 (Landsat 8 imagery via Mapbox Landsat-live)

With every pixel captured within the past 32 days, Landsat-live features the freshest imagery possible around the entire planet. – Camilla Mahon, Mapbox blog

Finally, a project that lets us understand how the planet changes in weeks, instead of the picture perfect – sunny, green satellite imagery that we are so used to by now thanks to Google Earth and other similar projects. Mapbox’s Landsat-live is going to help showcase the big gap between how we perceive the world in our maps with satellite imagery overlays and how it actually is. And of course, Mapbox choose to overlay the satellite imagery with OpenStreetMap data.

Chennai, India

With a 30 meter resolution, a 16 day revisit rate, and 10 multispectral bands, this imagery can be used to check the health of agricultural fields, the latest update on a natural disaster, or the progression of deforestation. – Camilla Mahon, Mapbox blog

Besides the Earth Observation projects that Landsat-live would make possible, I am sure it is not going to be long before someone decide to create the next Geoguessr with this project. Satguessr – the Landsat-live based Geography game! maybe we should Anyone interested in the idea?


Five years from now, real-time maps might be as ubiquitous as YouTube videos—but for now, they feel as futuristic as movies might have to Victorians. – Charlie Loyd, Mapbox toCitylabs


Mapbox’s Landsat-live project showcases the Landsat program in the kind of spotlight, it deserves.

P.S: @Mapbox: maybe you guys can think about adding a timeline functionality for the Landsat-live service! It would be all the awesome to see how things have changed in the last few satellite revisit periods.

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JavaScript for Geospatial applications: An Overview

By Muthukumar Kumar

JavaScript has formed a strong relationship with the Geospatial world (WebGIS, et.al) in a manner that is reminiscent of the relationship between Python and Desktop GIS. JavaScript is often regarded as more of a scripting language than a full-fledged object oriented language but I must admit it has got a much wider functionality than one might imagine and for the record, JavaScript is officially termed as Object-Scripting language (read: Mozilla’s JS page). If you are looking for an overview of programming languages used in GIS, have a look at my previous post.

While the capabilities of Desktop GIS and their applications are undisputed, there has been a steady growth in the number of WebGIS applications and Apps. Majority of such applications utilize one JavaScript library or the other. Depending on whether you just want to use JavaScript for developing a simple map for your website or visualize tweets in real-time, one of the many JavaScript libraries and tools might be of interest to you. Here’s an overview of JavaScript for Geospatial applications:

OpenLayers

OpenLayers has great documentation, a new version (3.0), lots of examples to get you started and the best thing of them all – Open source! Certainly my favorite JavaScript library and is one of the easiest ways to get a map on the web.

ESRI API for JavaScript

ESRI does it and does it well. Not for nothing, is ESRI considered as the GIS pioneer. Some of the functionality that you see with ESRI’s API is not that easily achievable with the Open source solutions especially if you have limited programming skills. However ESRI is not alone in the JavaScript for Geospatial arena and it looks like this is going to be one interesting competition.

CartoDB

CartoDB impressed us with their living cities visualization partnering with HERE and then they “wowed” us with the real-time geo-tagged twitter maps. Guess those two examples are enough to understand why CartoDB.js is a great library for geospatial applications. Here’s a presentation (Jan 2013) about using CartoDB to develop maps for the web.

MapBox

MapBox.js is another cool library for building interactive maps. FourSquare, Pinterest, National Geographic are some of the companies that utilize MapBox’s JavaScript libraries for their web maps.

D3

Data-Driven Documents or D3 is general purpose data visualization library. D3 is certainly a hot topic of discussion and development among geospatial professionals. Considering that D3 supports a new format called TopoJSON for topology data, this is a given I guess! Our geo-geek blog partners at digital-geography do most certainly love this. Here’s a blog post regarding mapping using D3.

Leaflet

Leaflet is a great tool for making mobile-friendly interactive maps and it extremely light-weight at 33 KB. Leaflet has a lot going for it and was one of the fundamental driving forces behind the recent redevelopment of OpenLayers 3.0.

Node.js & Node Postgres

Great JavaScript libraries for building a web based PostGIS application.

Open Weather Map API

Get detailed weather information using this free JavaScript API.

Cesium

Really cool JavaScript library for rendering interactive 3D (0r 2D) graphic visualizations without any plug-ins on the browser, requires WebGL though.

HERE Maps API

If you want to make use of the HERE’s awesome expertise with traffic information, routing and more.

StoryMap.js

The Open source alternative to ESRI’s Story map application.

And of course, Yahoo Maps API, Bing Maps API and Google Maps API. If you dont want to use the data from the big players, there is always OpenStreetMap.

Learning JavaScript
There are lots of JavaScript books, resources and tutorials available and to each one his/her own but you might want to have a look at OpenGeo’s resource for learing to use JavaScript for Geospatial applications aka programming WebGIS applications – OpenGeo’s JS page.

I am sure that I am missing a lot of really nice JavaScript libraries and APIs. It would be wonderful to have your input in this regard. After all, that’s what the comments section is for.

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