We run into this situation quite frequently at Azavea, so we’ve gotten to know many of the providers over the years. Lastly, there’s the difficult case of needing high resolution, recently collected imagery (especially if you plan to derive commercial works from that imagery and need access to the raw files). That imagery can also be downloaded from either Earth on AWS or the Earth Engine Catalog-you can also browse when the most recent imagery was collected for each state (and at what resolution) at this free online coverage map hosted by ESRI. In the U.S., the USDA’s National Agricultural Imagery Program (NAIP) captures 1m/pixel or better imagery for the entire contiguous United States once every other year. Make sure you familiarize yourself with the data before downloading a lot of it!įor high-resolution aerial imagery, your options are much more limited. A warning: these are very large files and the imagery itself is lower resolution than what you might expect to see on a typical web map.

MODIS (NASA’s satellite constellation which images the earth every 1-2 days)ĭata from all three of these satellite constellations can be downloaded for free from either Earth on AWS or Google’s Earth Engine Catalog.

Landsat 8 (the USGS’s satellite which images the earth once every 16 days).

Sentinel-2 (the European Space Agency’s constellation of satellites imaging the entire landmass of the earth once every five days).

Here’s where things get interesting-we’ve written previously about the explosion of freely available, openly licensed, and constantly updating satellite imagery in our blog post, An Introduction to Satellite Imagery and Machine Learning. For larger-area basemaps, satellite imagery providers make more sense:

and Australia and has a very simple user interface available through any web browser.

For high-resolution aerial imagery, NearMap orthographics provide great coverage in the U.S. Rather than license imagery from Google that they’re, in turn, licensing from imagery providers, it usually makes more sense to go directly to the source. Google’s Maps API is notoriously stingy in this regard, with its terms of service even limiting your right to display content derived from Google imagery on a map that isn’t also provided by Google. tracing building footprints or other cartographic features), you should consider a paid option that allows for derivative works to be produced. If you’re considering deriving a commercial product from the imagery you’re browsing (e.g. Some other great sources of non-commercial, non-downloadable imagery are:

Google earth free download 2020