Skip to content

Commit

Permalink
modifying readme
Browse files Browse the repository at this point in the history
  • Loading branch information
gbrencher committed Jun 3, 2024
1 parent 261a425 commit 7b68595
Show file tree
Hide file tree
Showing 3 changed files with 19 additions and 14 deletions.
4 changes: 3 additions & 1 deletion glacier_image_correlation/README.md
Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,9 @@ This set of Github Actions workflows allows you to measure horizontal glacier su
We use three workflows to make measurements of glacier surface velocity. For demonstration purposes the workflows are only set up to work over the [Yazghil Glacier](https://earth.google.com/earth/d/1myewNJrDEM0tW1_xdpWCYaRCGDcOBwiy?usp=drive_link) in Pakistan. To run the workflows, simply fork this repository, visit the "Actions" tab, and choose the `batch_image_correlation` workflow (which runs the other two workflows as well).

### 1. `image_correlation_pair`
This workflow calls a Python script (image_correlation.py) that runs autoRIFT on a pair of spatially overlapping Sentinel-2 images. It only requires the [product names](https://sentiwiki.copernicus.eu/web/s2-products) of the two images. The images are downloaded from aws using the [Element 84 Earth Search API](https://element84.com/earth-search/). Only the near infrared band (NIR, B08) is used which has a spatial resolution of 10 m. autoRIFT is used to perform image correlation. Search distances are scaled with temporal baseline assuming a maximum surface velocity of 1000 m/yr, so images acquired farther apart in time take longer to process. Surface velocity maps are saved as geotifs and uploaded as [Github Artifacts](https://docs.github.com/en/actions/using-workflows/storing-workflow-data-as-artifacts).
This workflow calls a Python script (image_correlation.py) that runs autoRIFT on a pair of spatially overlapping [Sentinel-2 L2A](https://docs.sentinel-hub.com/api/latest/data/sentinel-2-l2a/) images. It only requires the [product names](https://sentiwiki.copernicus.eu/web/s2-products) of the two images. The images are downloaded from aws using the [Element 84 Earth Search API](https://element84.com/earth-search/). Only the near infrared band (NIR, B08) is used which has a spatial resolution of 10 m. autoRIFT is used to perform image correlation. Search distances are scaled with temporal baseline assuming a maximum surface velocity of 1000 m/yr, so images acquired farther apart in time take longer to process. Surface velocity maps are saved as geotifs and uploaded as [Github Artifacts](https://docs.github.com/en/actions/using-workflows/storing-workflow-data-as-artifacts).

![plot](./images/input_images.png)

### 2. `batch_image_correlation`
This workflow can be used to create surface velocity maps from many pairs of Sentinel-2 images. Required inputs include maximum cloud cover percent, start month (recommend >=5 to minimize snow cover), end month (recommend <=10 to minimize snow cover), and number of pairs per image, e.g.:
Expand Down
Binary file added glacier_image_correlation/images/input_images.png
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
29 changes: 16 additions & 13 deletions glacier_image_correlation/notebooks/image_correlation.ipynb

Large diffs are not rendered by default.

0 comments on commit 7b68595

Please sign in to comment.