No Ozone or NCEP files found

[matthewhanson]

Hello,

We're trying to run Acolite on Sentinel-2 data and the output log indicates that it is unable to get ozone or NCEP files. We using a default settings file for now, until we can get things working then will be adding some additional products.

2021-01-30 02:39:42: Processing scene 1 of 1...
2021-01-30 02:39:42: 2021-01-30 02:39:42 - Processing L1C_T54HVH_A009451_20170414T003551
2021-01-30 02:40:38: Downloading file S20171040010423_TOAST.OZONE failed
2021-01-30 02:40:38: Downloading file N201710400_MET_NCEPR2_6h.hdf.bz2 failed
2021-01-30 02:40:38: Downloading file N201710406_MET_NCEPR2_6h.hdf.bz2 failed
2021-01-30 02:40:38: Downloading file N201710412_MET_NCEPR2_6h.hdf.bz2 failed
2021-01-30 02:40:38: Downloading file N201710418_MET_NCEPR2_6h.hdf.bz2 failed
2021-01-30 02:40:38: Downloading file N201710500_MET_NCEPR2_6h.hdf.bz2 failed
2021-01-30 02:40:38: Downloading file N201710400_O3_AURAOMI_24h.hdf failed
2021-01-30 02:40:38: No ozone file found for 2017-04-14
2021-01-30 02:40:38: No NCEP files found for 2017-04-14
2021-01-30 02:40:38: No ancillary pressure found: using default.
2021-01-30 02:40:38: No ancillary ozone found: using default 0.3.
2021-01-30 02:40:38: No ancillary ozone found: using default 1.5.
2021-01-30 02:40:38: Reading LUT data
2021-01-30 02:40:38: Reading LUTs took 0.7 seconds
2021-01-30 02:40:39: Starting DSF aerosol correction with fixed path reflectance.
2021-01-30 02:40:40: Writing band B1 to data/output//S2A_MSI_2017_04_14_00_35_51_T54HVH_L1R.nc

I looked through the manual but couldn't find any additional configuration info for ozone and NCEP data. Is this a known issue?

[acolite]

Hi Matthew

Ancillary file download now requires an EarthData account. I did forget to add this in the manual, and the information was a bit hidden in the forum. I have added a post in the FAQ: https://odnature.naturalsciences.be/remsem/acolite-forum/viewtopic.php?f=5&t=235

You need to register at https://urs.earthdata.nasa.gov/ and can put your EarthData credentials "Username" and "Password" either in the config/acolite_config.txt or your settings file:

EARTHDATA_u=Username
EARTHDATA_p=Password

Hope this helps!

Quinten

[matthewhanson]

Thanks a lot @acolite / Quinten , I added them as environment variables and it worked to download the NCEP files, but still getting an error for Ozone:

2021-02-02 06:06:30: 2021-02-02 06:06:30 - Processing L1C_T19TCH_A020300_20210124T154037
2021-02-02 06:07:28: Downloading file S20210240002423_TOAST.OZONE failed
2021-02-02 06:07:28: Could not retrieve ancillary data, proceeding with default values.
2021-02-02 06:07:28: No ancillary pressure found: using default.
2021-02-02 06:07:28: No ancillary ozone found: using default 0.3.
2021-02-02 06:07:28: No ancillary ozone found: using default 1.5.

This is a much newer file (Jan 24), so I thought that perhaps this is due to a latency in the Ozone data? I'll check an older file.

[acolite]

Hi Matthew - I noticed that too, and in fact the TOAST ozone files seem to be missing from May 2020. I added a date check in the ancillary download. The O3 AURAOMI files seem to be present so It would be using those. (The TOAST files were the second fall back dataset after AURAOMI and EPTOMS.) You can check your output files whether the default ozone has been used, e.g.

ncdump -h $ncf | grep uoz

With ncf the path to a L2R.nc file.

Quinten