Incorrect latitude and longitude values while processing S3_OL_1_EFR
Posted: Mon Jun 12, 2023 3:18 pm
Hi,
This is a problem I am seeing with polymer v4.14 while processing large numbers of S3A/B OLCI L1 Full resolution. Do let me know if this has been adressed in the latest version.
Variables latitude and/or longitude have single pixels or lines of pixels where the coordinates don't change monotonically. This leads to errors in Nearest Neighboor interpolation that is done for regridding outside polymer.
I have checked the SEN3 file in SNAP and I don't see latitude or longitude variables varying smoothly at the problematic locations.
A test image and location:
S3A_OL_1_EFR____20181224T044219_20181224T044519_20181225T093129_0180_039_247_2520_LN1_O_NT_002.SEN3
After loadint the polymer netcdf file with python's xarray:
polymer = xr.open_dataset(input_fname)
lon_2d = polymer['longitude'].values
lat_2d = polymer['latitude'].values
print('lon',lon_2d[1147, 988:994])
print('lat',lat_2d[1147, 988:994])
lon [90.634263 90.634263 88.812747 88.812747 90.653342 90.653342]
lat [28.117857 28.117857 28.38913 28.38913 28.114886 28.114886]
Thanks for your help
This is a problem I am seeing with polymer v4.14 while processing large numbers of S3A/B OLCI L1 Full resolution. Do let me know if this has been adressed in the latest version.
Variables latitude and/or longitude have single pixels or lines of pixels where the coordinates don't change monotonically. This leads to errors in Nearest Neighboor interpolation that is done for regridding outside polymer.
I have checked the SEN3 file in SNAP and I don't see latitude or longitude variables varying smoothly at the problematic locations.
A test image and location:
S3A_OL_1_EFR____20181224T044219_20181224T044519_20181225T093129_0180_039_247_2520_LN1_O_NT_002.SEN3
After loadint the polymer netcdf file with python's xarray:
polymer = xr.open_dataset(input_fname)
lon_2d = polymer['longitude'].values
lat_2d = polymer['latitude'].values
print('lon',lon_2d[1147, 988:994])
print('lat',lat_2d[1147, 988:994])
lon [90.634263 90.634263 88.812747 88.812747 90.653342 90.653342]
lat [28.117857 28.117857 28.38913 28.38913 28.114886 28.114886]
Thanks for your help