CHRIS/PROBA-1 Radiometric Calibration Assessment

The radiometric calibration assessment assessed the spectral response changes over time for the Compact High Resolution Imaging Spectrometer (CHRIS)/Proba-1 mission. As Barrax was the test site for the 2003/2004 SPARC campaign and has been acquired since, it was chosen.The results presented have shown a comparison of in-situ spectra measured during the ESA SPARC, SEN2FLEX and SEN3EXP campaigns with CHRIS/Proba-1 imagery acquired between 2003 and 2019 at the Barrax site in Spain. The CHRIS imagery were processed using the CHRIS-Box, and results indicate that the measurements in the first band in Mode 1 are significantly underestimated and in the Near-InfraRed (NIR) are slightly overestimated. The low value at the blue end is expected from the previously calculated CHRIS calibration coefficients, while previous results suggested the near-infrared was also underestimated.Further analysis will focus on using the atmospheric campaign data to see if the potential errors and uncertainties in the CHRIS atmospheric correction can be reduced. Also, the campaign airborne and satellite data can be compared to the CHRIS and in-situ spectra.