Relying on Earth targets for the calibration of radiometers used for the generation of multi-decadal FCDR raises the following question: to what extent climate change or other environmental changes can affect the spectral signature of these “pseudo invariant” targets and therefore the consistency of the calibration?
We have tackled the issue about the uncertainty due to noise of the MW sounders - here we briefly present the main outcomes of our study: First, what do we call noise and how do we calculate it? Second, how does the noise evolution actually look like? Third, what data can be used? And last, does the story end here?
Using surface and TOA reflectance uncertainties and aerosol type uncertainties to constrain estimates of uncertainties in retrieved aerosol optical depth from AVHRR