Duplicate (overlapping) MERIS and OLCI orbits

[andrei_mitrich]

When processing L1B data to L3bin, mostly for MERIS, also for OLCI, we noticed that for about 10%-25% of all days, there are pairs of files, from one to 5 pairs daily, with partially overlapping areas; they also share the same relative number of the orbit in cycle. If including both files for each pair, we not only corrupt parameter "number of observations", also are averaging not fully coinciding reflectances. The question is: which of partially overlapping orbits to select? What was the reason to include pairs instead of one orbit?

Below is an example for 2003-07-09, with partially overlapping areas and sharing the same relative numbers: 18, 19, 20, and 30 - four pairs totally:

EN1_MDSI_MER_RR__1P_20030709T010907_20030709T015306_007085_0017_20180601T101053_0100.ZIP
EN1_MDSI_MER_RR__1P_20030709T024943_20030709T033341_007086_0018_20190125T142725_0100.ZIP
EN1_MDSI_MER_RR__1P_20030709T025533_20030709T033342_007086_0018_20180601T100915_0100.ZIP
EN1_MDSI_MER_RR__1P_20030709T043019_20030709T043755_007087_0019_20180601T100422_0100.ZIP
EN1_MDSI_MER_RR__1P_20030709T043753_20030709T051418_007087_0019_20180601T102028_0100.ZIP
EN1_MDSI_MER_RR__1P_20030709T061055_20030709T065457_007088_0020_20180601T103418_0100.ZIP
EN1_MDSI_MER_RR__1P_20030709T061816_20030709T065455_007088_0020_20180601T102947_0100.ZIP
EN1_MDSI_MER_RR__1P_20030709T075131_20030709T083533_007089_0021_20180601T103542_0100.ZIP
EN1_MDSI_MER_RR__1P_20030709T093207_20030709T101609_007090_0022_20180601T103553_0100.ZIP
EN1_MDSI_MER_RR__1P_20030709T111244_20030709T115645_007091_0023_20180601T103743_0100.ZIP
EN1_MDSI_MER_RR__1P_20030709T125319_20030709T133721_007092_0024_20180601T103825_0100.ZIP
EN1_MDSI_MER_RR__1P_20030709T143355_20030709T151757_007093_0025_20180601T103854_0100.ZIP
EN1_MDSI_MER_RR__1P_20030709T161432_20030709T165833_007094_0026_20180601T104015_0100.ZIP
EN1_MDSI_MER_RR__1P_20030709T175508_20030709T183909_007095_0027_20180601T104351_0100.ZIP
EN1_MDSI_MER_RR__1P_20030709T193544_20030709T201945_007096_0028_20180601T104404_0100.ZIP
EN1_MDSI_MER_RR__1P_20030709T211620_20030709T220021_007097_0029_20180601T104624_0100.ZIP
EN1_MDSI_MER_RR__1P_20030709T225656_20030709T225854_007098_0030_20180601T102128_0100.ZIP
EN1_MDSI_MER_RR__1P_20030709T225853_20030709T234056_007098_0030_20180601T104640_0100.ZIP

[OB ODPS - towens]

ESA will republish files. I you look at the last date/time node in the file name, that is the create date. Where there is an overlap, use the file with the most recent create date.

EN1_MDSI_MER_RR__1P_20030709T024943_20030709T033341_007086_0018_20190125T142725_0100.ZIP
EN1_MDSI_MER_RR__1P_20030709T025533_20030709T033342_007086_0018_20180601T100915_0100.ZIP

Tommy