Duplicate observations in the same archive?

Optical Toolbox
#21

@simonf
Hello Simon,

Sorry, but no. I’m not sure what the policy on this is. It may be deliberate, or it may be that these instances (I don’t know the number of occurences) have been overlooked. It’s probably best to ask via the helpdesk at coordesk.support@copernicus.esa.int

Cheers

Jan

#22

Jan,

What’s an AMALFI report? How can we get our hands on those?

This kind of duplication happens also with GRD data, especially pre-June 2017. Several 1000s of records.

Guido

#23

Hi Guido,

AMALFI is the QC software that checks the data as it’s processed in the PDGS. In the S1, at the highest level, there is an AMALFI Quality Control Report in PDF:

image.png1539×763 168 KB

When I checked the SciHub the other day, I looked at this Report, and identified that the product in question was from two processings.

Cheers

Jan

#24

Ok, thanks. I will look into some of the GRD cases.

#25

I would expect the GRD-cases to have differing processing centers and orbit quality, for example.

#26

Here is an example which is present 3 times, all with the same processing center, software version, etc. I don’t know whether orbit quality is different, but one would somehow expect only the “best” would be retained in such cases?

By the way, the duplication problem is more severe in 2016 and less so in 2017 (i.e. my earlier statement was not correct).

S1A_EW_GRDM_1SDV_20160329T074851_20160329T074951_010581_00FBCB_83F3
S1A_EW_GRDM_1SDV_20160329T074851_20160329T074951_010581_00FBCB_9B13
S1A_EW_GRDM_1SDV_20160329T074851_20160329T074951_010581_00FBCB_F63C

#27

The metadata must differ somehow, perhaps it’s orbits or processing times.

#28

Hi Guido,
I’ve looked at the AMALFI Report creation dates:

Amalfi Quality Control Report
S1A_EW_GRDM_1SDV_20160329T074851_20160329T074951_010581_00FBCB_83F3 Date: 2016-03-30T13:37:47
S1A_EW_GRDM_1SDV_20160329T074851_20160329T074951_010581_00FBCB_F63C Date: 2016-03-30T21:33:15
S1A_EW_GRDM_1SDV_20160329T074851_20160329T074951_010581_00FBCB_9B13 Date: 2016-03-31T07:14:04

AMALFI seems to have been run at three distince times, presumably triggered by the production of the data. According to the manifest.xml they all seem to have been processed at ‘Copernicus S1 Core Ground Segment - UPA’ (which is the Airbus DS data centre in Newport (Wales)).

So - barring the above additional info - my investigations have found no rationale for the presence of the repeated data on the Catalogue. So I think you should raise your query to the Copernicus Helpdesk (coordesk.support@copernicus.esa.int).

Cheers

Jan