Sentinel-2 missing pieces

Optical Toolbox
#1

Is it normal that Sentinel-2 tiles have missing pieces?
Like this example from yesterday over Corsica.

#2

Hello @gbrelstaff

Normal? That depends. It’s obviously not normal, but it is a known issue - Lost Packets due to reception errors, and highlighted in the L1C Data Quality Report - that is found reasonably often. Lost Packets can affect the Full Swath, individual Tiles in a Datastrip, or individual Bands within a single Tile. They can be identifed in SNAP Mask Manager. In extreme case -as was identified earlier in June - there can be a geolocation shift after the missing data. But generally, the issue is limited to gaps in the data*

*I have since checked a Tile (32TMK) from the DS in SNAP can confimr that the Geolocation and Co-registration is NOMINAL and the Datastrip General Quality Report (DS_VGS2_20210702T121947_S20210702T101805\QI_DATA\GENERAL_QUALITY.xml) identifies 1258 Lost Packets spread across the 10 metre and 20 metre Bands.

Cheers

Jan

Cheers

Jan

S2 MPC Operations Manager

3 Likes
#3

Thanks Jan

there is also another indicator of quality failure in the associated L2A MTD_MSIL2A.xml file where we find a FAILED in the GENERAL_QUALITY:

<n1:Quality_Indicators_Info>
   <Cloud_Coverage_Assessment>20.845778</Cloud_Coverage_Assessment>
   <Technical_Quality_Assessment>
            <DEGRADED_ANC_DATA_PERCENTAGE>0.0</DEGRADED_ANC_DATA_PERCENTAGE>
            <DEGRADED_MSI_DATA_PERCENTAGE>0</DEGRADED_MSI_DATA_PERCENTAGE>
   </Technical_Quality_Assessment>
   <Quality_Control_Checks>
            <Quality_Inspections>
                <quality_check checkType="FORMAT_CORRECTNESS">PASSED</quality_check>
                <quality_check checkType="GENERAL_QUALITY">FAILED</quality_check>
                <quality_check checkType="GEOMETRIC_QUALITY">PASSED</quality_check>
                <quality_check checkType="RADIOMETRIC_QUALITY">PASSED</quality_check>
                <quality_check checkType="SENSOR_QUALITY">PASSED</quality_check>
            </Quality_Inspections> ...
    </Quality_Control_Checks>
</n1:Quality_Indicators_Info>
1 Like
#4

Hi @gbrelstaff

Indeed. Yes. You’re right. I mentioned the L1C because it underpins the L2A and my default is to go to the GENERAL_QUALITY Report in the L1C DS when I see images like the one you posted.

Cheers

Jan

S2 MPC Operations Manager