I recently contacted the USGS regarding the Landsat data available via the Google Earth Engine platform. During the course of email correspondence, a USGS staff member shared that the Google applies additional corrections to the Landsat data when it is ingested and offered via their catalog. The same USGS staff member indicated that Google has not communicated what those additional corrections are to the USGS. As a consequence, the USGS staff member was unable to comment on whether a time-series analysis I planned could be carried out using the data available via GEE.
If GEE applies additional corrections to the Landsat data when it is ingested into their catalog, then what are these corrections?
I have looked at the metadata associated with the data sets in GEE catalog, and I see no clear reference to additional corrections being applied, but I trust that this USGS staff member understands and accurately conveyed the situation.