We are pleased to announce the release of the new Aerosol Optical Thickness (AOT) masks for the PROBA-V Collection 2 (PV C2) data. These masks are designed to enhance the accuracy of our atmospheric correction process and improve the quality of the Top-Of-Canopy (TOC) reflectance and NDVI data.
Why is this important?
The PV C2 data was atmospherically corrected using MERRA-2 data from NASA, which includes inputs for water vapour, ozone, and AOT. However, very high AOT values can result in high TOC reflectance, particularly affecting the Blue channel and, to a lesser extent, the Red, NIR, and SWIR channels. This can lead to artefacts in the data, such as bright 'halos' around masked values.
To address this issue, we have introduced additional AOT masks that should be used to filter out areas impacted by high AOT values. These masks are provided in all three resolutions (100 m, 333 m, and 1 km) and for all compositing steps (S1, S5, and S10). By applying these masks, you can ensure that the TOC reflectance and NDVI data are more accurate and reliable.
Please refer to the technical note for detailed information on these masks and the impact assessment of using different thresholds. The Product User Manual provides detailed instructions on how to apply these additional masks.
If you have any questions or need further assistance, please do not hesitate to contact us.