Integration with GEE

[EmanuelCastanho]

Is it possible to integrate Acolite with Google Earth Engine? Is this a possible feature to be implemented in the future?

[acolite]

Hi Emanuel

Thanks for your question! It would be nice to have the processor in Google Earth Engine, but there are a few challenges to overcome. There has been a bit of interest for porting ACOLITE to GEE or integrating the GEE API in ACOLITE. There is a thread on the forum about this, but not much has happened in a while: https://odnature.naturalsciences.be/remsem/acolite-forum/viewtopic.php?f=4&t=212

For running everything on GEE itself, the main challenges are (1) porting the code to using GEE functions, and (2) the use of LUTs in the atmospheric correction. (I think using large external files like the NetCDF LUTs is not the GEE way.)

With the GEE API it may be possible to run the atmospheric correction and LUT interpolation locally, but do the processing remotely. Which should reduce data transfer significantly, but is not a true GEE implementation.

Quinten

[EmanuelCastanho]

I was thinking of using local processing where the inputs to ACOLITE would be the L1 bands exported from GEE (.tif) together with metadata parameters also exported from GEE. Is something like this possible? Or the use of ACOLITE can only be performed with the original Sentinel-2 product in .SAFE format? Thank you for your excellent work on ACOLITE!

[acolite]

Hi Emanuel

I am currently developing this feature! The data source is GEE, but ACOLITE/DSF is ran locally. The full GEE implementation is more difficult and maybe not feasible at this time.

I am evaluating two options for ACOLITE-GEE integration: one where the data is downloaded and processed locally, the other a more hybrid set up where no data is necessarily downloaded until the end of processing. Both options could have slightly different results from processing original scenes locally, and I will need to evaluate this. (This is especially true for Sentinel-2 where GEE does not have the full geometry metadata.)

Let me know if you have any comments or suggestions. This or these options will be available in due course. :-)

Quinten

[hackerquanw]

Hi Quinten

Firstly, thanks for your work! How about the progress about use data source of GEE? i read the recently user manual of acolite and find that input file also need .safe for sentinel-2.

Quan

[carolineowens]

Hi all, thanks for this great software! Is there any update on ACOLITE in GEE - particularly to correct Sentinel-3 OLCI imagery?

[acolite]

Hi Caroline

For Sentinel-3, the data that currently are on GEE are not suitable for processing with ACOLITE. The viewing (and sun) geometry is missing so we cannot compute the atmospheric correction parameters. You'll see only the radiances are included: https://developers.google.com/earth-engine/datasets/catalog/COPERNICUS_S3_OLCI#bands

For Landsat and Sentinel-2 I have implemented a hybrid version, which is currently not documented, and some issues remain to be solved. I plan to document and write a paper about it sometime this year. I have been contacted recently by someone from GEE itself that expressed interest in integrating ACOLITE within GEE. I am not sure about their commitment and how this attempt will evolve.

I hope this helps!

Quinten

[carolineowens]

This is a huge help Quinten, thank you!! Warmly, Caroline

…

On Wed, Jul 12, 2023 at 11:36 PM Quinten Vanhellemont < ***@***.***> wrote: Hi Caroline For Sentinel-3, the data that currently are on GEE are not suitable for processing with ACOLITE. The viewing (and sun) geometry is missing so we cannot compute the atmospheric correction parameters. You'll see only the radiances are included: https://developers.google.com/earth-engine/datasets/catalog/COPERNICUS_S3_OLCI#bands For Landsat and Sentinel-2 I have implemented a hybrid version, which is currently not documented, and some issues remain to be solved. I plan to document and write a paper about it sometime this year. I have been contacted recently by someone from GEE itself that expressed interest in integrating ACOLITE within GEE. I am not sure about their commitment and how this attempt will evolve. I hope this helps! Quinten — Reply to this email directly, view it on GitHub <#28 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AMCV2QFR5VBAEJWLOF57HKDXP53MBANCNFSM5S5FGXAQ> . You are receiving this because you commented.Message ID: ***@***.***>

[dhritirajsen]

Hello Quinten,

Is there any update on the integration of ACOLITE with GEE? Thanks again for your amazing work.

[pmannoni]

Thank you for your work towards integrating Acolite processing in GEE !