S1GRD dates matching between sentinelhub and copernicus open access hub

[peterjames.zellner]

Dear EDC Team,
we were comparing available dates in the EDC S1GRD collection and on Copernicus open access hub. They are not the same. Is there an explanation for that?
Loading S1 like this:

bbox = catchment_outline.bounds.iloc[0]
start_date = date(2021, 1, 1)
end_date = date(2021, 7, 1)
cube_config = CubeConfig(
    dataset_name='S1GRD',
    band_names=['VV', 'VH'],
    bbox=bbox.tolist(),
    spatial_res=0.0018,   # = 100 meters in degree>
    time_range=[start_date.strftime("%Y-%m-%d"), end_date.strftime("%Y-%m-%d")]
)

Gives (upper part of the image):

On Copernicus open access hub (lower part of the image) we get dates that are not in this list for example: 01-09, 01-11.
Additional check: for january 2018 xcube finds 10 s1 images… in the ESA catalog there are 17.

[william.ray]

Hi Peter,

Thanks for the question two things that I think are worth checking:

1. On the Copernicus Open Access Hub, I can see that you are ordering your products by Ingestion Date, not Acquisition Date. Are you using the correct parameter when searching for images in the Open Access Hub?
2. There are several acquisitions modes used by Sentinel-1 GRD. Sentinel Hub data collections only include IW and EW acquisition modes. Therefore, if you filter by these modes, you should have the same number of results from both services. Of course, if there is still a discrepancy, then we will look into it for you

[peterjames.zellner]

Hi William,
thanks for your quick reply and advice. We’ve taken that into account and prepared a new example. Still it seems like some dates are missing in shub.
Copernicus (left, 2 dates), EDC/Sentinelhub request (right, one date),

[william.ray]

Hi Peter, using Catalog API I can see both the tiles that you are returning in Open Access Hub.

Can you share the code snippet in your notebook so I can replicate your issue in EDC please? I want to make sure my cube is configured exactly the same as yours

[peterjames.zellner]

Hi William, here’s the snippet

bbox = (11.15, 46.7, 11.2, 46.75)
cube_config = CubeConfig(
    dataset_name='S1GRD',
    band_names=['VV', 'VH', 'localIncidenceAngle'],
    bbox=bbox,
    spatial_res=0.0018,   # = 100 meters in degree>
    time_range=['2021-01-08', '2021-01-10'],
)

And looking at it

cube = open_cube(cube_config, api_url="https://creodias.sentinel-hub.com")
cube.time

Gives

xarray.DataArray'time'time: 1
array(['2021-01-08T05:18:46.000000000'], dtype='datetime64[ns]')
Coordinates:
time
(time)
datetime64[ns]
2021-01-08T05:18:46
Indexes: (1)
Attributes:
standard_name :
time
bounds :
time_bnds

[william.ray]

Hi Peter,

If you remove api_url="https://creodias.sentinel-hub.com" then you will return two acquisitions in your time range. Was there a particular reason why you were using Creodias as your API URL?