Adjusting Threshold on S2 Satellites Issue

[Russ-Nasrallah]

When trying to adjust the threshold values on S2 satellite images, If I modify the threshold at all, most of the shoreline disappears.
before:

after:

The adjustment between these two images was very small and yet most of the shoreline digitization has disappeared.

Any thoughts? This behavior only happens on the S2 imagery as far as I can tell.

[Russ-Nasrallah]

@kvos any thoughts on this? I'd like to be able to modify the values but can't if it doesn't work for the highest quality satellite returns. Thanks!

[Mascagni-ML]

It is a very curious bug, I tested it in different regions of the world and this always happens with Sentinel-2, but it doesn't happen with Landsat collections. Why?

[Russ-Nasrallah]

It is a very curious bug, I tested it in different regions of the world and this always happens with Sentinel-2, but it doesn't happen with Landsat collections. Why?

I'm glad someone else was able to replicate it. I was worried it was an issue on my end. And yes it is curious that it only effects the sentinel-2 images.

[kvos]

this has to do with your reference shoreline and settings['max_dist_ref'] threshold. Those settings define how far from the reference shoreline you can digitise points, so it could be that you are going too far when moving the threshold. Try to increase that parameter and see if it fixes it.

[Russ-Nasrallah]

this has to do with your reference shoreline and settings['max_dist_ref'] threshold. Those settings define how far from the reference shoreline you can digitise points, so it could be that you are going too far when moving the threshold. Try to increase that parameter and see if it fixes it.

Hi Kilian,
Thanks for the suggestion. Unfortunately, I do not think this is the issue.

1. I am not using a reference shoreline
2. I can return the threshold adjustment to exactly the same position and the original shoreline does not show up.
3. it only occurs with the Sentinel-2 satellite returns. not L8 or L9.