OLCI mountain shadow around nadir view creates artefact. The reason is that view angle tie point grids have discontinuities around nadir. Simple Interpolation between those values is wrong, but can be fixed with a more advanced interpolation which was already used in SaRONG project.
fixed, tested with S3B_OL_1_EFR____20210329T141202_20210329T141502_20210330T193011_0179_050_338_3600_LN1_O_NT_002.SEN3, committed to Idepix master, 8.x and renovation branches. OD, 20211018.
OLCI mountain shadow around nadir view creates artefact. The reason is that view angle tie point grids have discontinuities around nadir. Simple Interpolation between those values is wrong, but can be fixed with a more advanced interpolation which was already used in SaRONG project.