Hi all
Processing of L1 ENVISAT/MERIS data in the SEN3 format is supported in ACOLITE, these have been released by ESA with the 4th reprocessing data release in July 2020. You can use the L1 FRS data either from OBPG's OceanColor browser, or from ESA's earth online page.
As of today the GitHub code handles both datasets by parsing the sensor information from the xfdumanifest.xml file rather than from the file name. The binary version 20221025.0 still gets this information from the file name, and supports files starting with EN1_ (i.e. those from OBPG), and requires renaming of the files starting with ENV_ (i.e. those from ESA) to start with EN1_. For example to be able to process the following scene with the 20221025.0 binary, rename
ENV_ME_1_FRG____20030218T101825_20030218T102301_________________0276_014_008______DSI_R_NT____.SEN3
to
EN1_ME_1_FRG____20030218T101825_20030218T102301_________________0276_014_008______DSI_R_NT____.SEN3
Future binary versions (i.e. after 20221025.0) and up to date GitHub code should not require this change. Note that no default gains are implemented at this point for MERIS, but ACOLITE should support you providing your own gains.
I hope this is useful to someone!
Quinten