Working with Export Locations - Drive vs. Cloud

EEDL works by using Earth Engine’s built in export mechanisms, which can send exported images either to Google Drive or to a Google Cloud storage bucket. In order for EEDL to finish processing exports - that is, for it to handle downloading and mosaicking images for you, you’ll need to either set up a Google Cloud storage bucket, configured for public access, or install the Google Drive client on your computer. The package does not currently use either the Google Cloud APIs or Google Drive APIs, avoiding the need for authentication, but presenting some limits and requirements on use.

Google Drive Exports

Note

Key takeaway: If you can run the Google Drive client on the same

computer as you’re running EEDL and have enough space in Drive for your exports, Drive exports may be a good option for you.

Key Considerations

Linux users may need to use the Cloud export option because available options for accessing Drive folders on Linux are lacking. If you have Drive set up as a directory on your computer though, you can use this format.

EEDL does automatically delete files it processes out of Google Drive, but it only moves the files to your Drive Trash, which you can only clear in their web interface. Your storage will continue being occupied for 30 days, until Drive automatically deletes the files from your Drive Trash, unless you manually go in and empty your Trash within the Google Drive web interface. For especially large exports/sets of exports, you may need to clear your trash midway through, depending on your available Drive storage.

This method is private - files aren’t shared or available to anyone else.

Google Cloud Exports

Key Considerations

Exports are public and accessed via public URL structure. Don’t export sensitive information via Cloud. If you want an option to access private buckets, please get in touch about submitting a pull request. Our client does not delete files automatically as it does not carry permissions to perform that operation (want it to be able to do that? Get in touch about submitting a pull request with code for that). We recommended setting a bucket lifecycle setting that automatically deletes files after 24 hours to save on costs and not manage files. EEDL will automatically download files within minutes in most cases.

While Earth Engine’s exports are publicly available and linkable here, EEDL does not upload any derived products (mosaics or zonal stats) back to the bucket, so those do not become public.

Note

Key takeaway: If you can’t run the Google Drive client, lack space

in Drive, want to bill export storage to a Cloud project, want the files available externally, or want the most reliable export method, using Google Cloud exports may be a good option for you.

Due to the current way EEDL pulls images from Google Cloud Storage, there is a limit of 1000 tiles per exported image, though more than 1000 tiles can be waited for at a time for multiple image exports. Few single image exports will hit this limit - by default, EEDL allows 12800 pixels per side of a tile, configurable to more or less if your image requires (especially multiband images). Broad-scale, but high resolution images may hit this limit and will either need to export to Google Drive, or will need to build an improved implementation for pulling tiles from Google Cloud. The limit stems from Google Cloud Storage’s public bucket listing only providing 1000 items - EEDL doesn’t detect or traverse pages at this time.