I've considered using HLS data for a research project related to time series analysis of forest areas in central Germany. The AOI is the state of Thuringia, which includes the tile '32UPB' and multiple surrounding tiles (9 in total).
Using the Python package nasa_hls* I was able to check how many datasets are available per year for my entire AOI. The result is 249 for 2018, 506 for 2020 and 0 datasets for all other years. A bit disappointing and not really the best foundation to do time series analysis with. I've also checked some other tiles in Europe and they all showed a continuous dataset.
I was not able to find any information about the reason for this data gap in central Germany and if the missing data will be available any time soon. I hope that someone here can enlighten me :)
Thanks and regards from Germany,
Thank you for your question. A Subject Matter Expert was notified to provide an answer for your question. Please excuse any delay as Thanksgiving breaks have just begun.
This is Brett from LP DAAC. I believe the HLS 1.4 is a Goddard product. Here at LP DAAC we have HLS 1.5, however I think it is a little different: https://lpdaac.usgs.gov/products/hlss30v015/
It is provisional Surface Reflectance data. Please let me know if we can help you with the 1.5.