5

There are numerous ways to import Google Earth imagery into the QGIS (e.g. OpenLayer plug-in or XYZ tiles), however the recent-most images are downloaded. Is there any way to import historical imagery? My project's related to tracking land use dynamics and it would be great if I could switch between imagery from different years.

1

I don't know of a good automated way. Here's what I do.

  1. In QGIS, create a layer with the ROI - as a rectangle or two diagonal points - saved as KML

  2. Import the KML into GE, zoom to the ROI, keep it viible, and select the historical imagery desired.

  3. Make sure to reset tilt and compass.

  4. Save as image, removing all extraneous decorations under Options, and saving at a sensible, most likely highest resolution.

  5. In QGIS, georeference the saved image, with CRS = 3857, transformation type = linear, only generating a world file not resaving the image. Use two diagonal points of the ROI as the reference points.

As caveats, realize that GE has the underlying image stored somewhere - inaccessibly - as XYZ tiles in usual tiling resolution steps. You are exporting at a different resolution, and would not be easy to perfectly match (given GE zooms out from the loaded ROI slightly). So you're piling multiple image resamplings on each other.

Second, your ROI points/rectangle will be marked on the image. So might need a second, "outer" ROI that's bigger than your actual one.

Third, be aware of usage/licensing restrictions. I believe Google's usage terms are pretty restrictive. So you might be violating their TOI by doing this at all, and are pretty sure to be violating if you use this in the context of any professional/commercial activity!

As an extra trick, if you are D/L multiple historical imagery, if you are careful then GE will not change the window in between if you do absolutely nothing else than change the imagery date. In this case, you can then just copy the world fine generated in Step 5 for your first image to all the other saved images.

0

my understanding is that the plugins are using Google Maps. This is a different product to Google Earth (GE) (and Google Earth Engine (GEE), there is also a Google Maps Engine it seems, which I don't know about).

The Google Maps product from Google, does not as far as I know have historical imagery.

You would need to access GE or GEE. There used to be a connector for GEE and QGIS but it was not built primarily for the purpose of accessing historical imagery, plus I think it is out of date now.

So, no.

I'd be interested to hear how you get on because I get similar questions.

For a single site case I would capture a screenshot of the historical image in GE and reproject that as a raster in QGIS.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.