Is there any web-service currently available which is hosting satellite images as open-source, just like OSM web-service hosting vector maps? We want to make a real-time traffic monitoring commercial application for Turkey and want a hybrid map as our base-layer (OSM layer + Satellite Images with 50% transparency). Images where roads are easily visible are suffice and young images are more preferable.
Landsat is now available via Amazon Web Services
Landsat 8 data is available for anyone to use via Amazon S3. All Landsat 8 scenes from 2015 are available along with a selection of cloud-free scenes from 2013 and 2014. All new Landsat 8 scenes are made available each day, often within hours of production.
To process this there are many open source tools coming out daily
This step-by-step post walks through processing Landsat 8 imagery into an interactive map that you can integrate into your website or app. We’ll cover the process from finding and downloading the image data, through processing it and adjusting its color balance, to bringing it into TileMill and exporting it as an interactive web map – where it can be combined with markers, animation, and other layers using MapBox.js. We’ll use open source tools throughout, and many of the techniques you’ll see will also apply to other satellite and aerial data, like Landsat 7, MODIS, and even commercial imagery.
Landsat 4-8, Sentinel 1 & 2, MODIS, SPOT 5-7, KOMPSAT and a dozen more are available at LandViewer for use. All of the imagery is regurally updated and the database of older images is also available.
Here's an example of a recent satellite image taken over Istanbul.
You can also filter imagery based on the satellite, date, cloudiness, sun elevation and more.