ACOLITE/DSF OLCI compared to Bahia Blanca AERONET-OC data

[quinten]

This post discusses matchups between ACOLITE processed OLCI data and Bahia Blanca AERONET-OC data, and is a response to poor results published by Arena et al. 2024 (e.g. their Fig. 5 and discussion about ACOLITE/DSF).

AERONET-OC lev20 data (accessed 2024-02-13) were used, and good days for matchups were determined (i.e. those with at least 5 valid lev20 measurements) to obtain Sentinel-3 data from CDSE (accessed 2024-02-13). Satellite data between 2021-09-21 and 2022-12-28 were downloaded and processed with an ACOLITE GitHub clone dated 2024-02-14.

Three configurations of ACOLITE/DSF were used to test sensitivity to settings:
1) Crop, subset to a ~36 km ROI over the Bahia Blanca AERONET site,
2) CropFixed, using the same subset, but using a single aerosol optical depth estimate over the ROI,
3) Full, full scene processing with all the defaults.

Mean and standard deviation were computed for a 3x3 pixel box centred on the site location, taken as -39.148333N, -61.721667E. The closest same-day AERONET measurement was used as reference.

Example spectra:

S3A_OLCI_2022_04_14_13_33_01_spectrum.png (48.93 KiB) Viewed 45804 times

S3B_OLCI_2022_10_15_13_23_40_spectrum.png (48.07 KiB) Viewed 45804 times

Lwn scatter plots for bands 3 to 6:

Band Oa03 443 nm

Oa03_scatter.png (37.13 KiB) Viewed 45804 times

MAPD <9%, RMSD <0.35, MAD <0.24

Band Oa04 490 nm

Oa04_scatter.png (36.43 KiB) Viewed 45804 times

MAPD <5%, RMSD <0.24, MAD <0.10

Band Oa05 510 nm

Oa05_scatter.png (36.11 KiB) Viewed 45804 times

MAPD <4%, RMSD <0.24, MAD <0.08

Band Oa06 560 nm

Oa06_scatter.png (37.85 KiB) Viewed 45804 times

MAPD <4%, RMSD <0.24, MAD <0.06