Harmonization or fusion of Landsat and Sentinel-2 data for geomorphological analysis of Italian rivers

[rositaauriemma]

I’m not sure if this is the right place, but let me explain what I would like to do: I need to harmonize or fuse Landsat data from 2000 with Sentinel-2 data starting from 2019. I realize that the time gap is quite large, so I’m unsure whether the results will be consistent. Specifically, I’m interested in analyzing the geomorphological changes of the major rivers in Italy. What would you suggest?
I'm aware that the large time gap might affect the consistency of the results, especially in terms of data comparability.

[LP DAACx - lien]

Hello,
I will ask some science folks there thought on this. So, just to make sure, do you want something like our HLS data, only rather then 2-3 days apart it is several years: https://doi.org/10.5067/HLS/HLSL30.002
Thanks,
Brett

[rositaauriemma]

Hi Brett,
Thank you for your reply. The idea is to cover a longer time span by incorporating Landsat data starting from 2000 and harmonizing or fusing it with Sentinel-2 data from 2019 onwards. This would allow me to analyze geomorphological changes in Italian rivers over an extended period.

However, I’m unsure whether such a fusion would make sense, given the large time gap between the datasets. Do you think this approach is feasible, or would you suggest a different method?

Thanks again for your insights!
Rosita

[LP DAACx - lien]

Thanks Rosita for the follow up.
I will see if our science folks have any suggestions. Also, hopefully someone from the generally science community that has some thoughts on this will chime in. I will let you know what I hear. Have a good weekend.
Brett

[LP DAACx - lien]

Hi Rosita,
I ran this by some science folks and we really don't think there is a good answer on how this can be done satisfactorily. The advantages of our HLS products are they take Landsat 8 and 9 and Sentinel 2 and use the same processing algorithm and are able to get coverage every 2-3 days at 30 meters. We don't see how this can be done with one satellite that revisits every 16 days.
Thanks,
Brett

[rositaauriemma]

Thank you for the clarification regarding the HLS products. I understand the challenge of addressing such a large temporal gap between datasets and the limitations due to revisit times.
Frankly, Sentinel-2 provides an image every 5 days over the same area, while Landsat revisits roughly every 16 days. However, the main issue is the large temporal gap between the two datasets. For this reason, I don’t think combining them would be very logical in this context.

Thank you again for your help and insights!

Merci
Rosita