ACIX aimed to bring together the developers of Atmospheric Correction (AC) processors, who were invited to generate the corresponding Bottom-Of-Atmosphere (BOA) products. The European Space Agency and NASA organise this exercise on AC processors inter-comparison using Landsat-8 and Sentinel-2 imagery of various sites, i.e. agricultural, snow/artic areas, deserts and coastal. A common and harmonised inter-comparison procedure was agreed and followed by all the participants.

For more information about the ACIX workshops, please follow the links to the SPPA web pages: ACIX I 1st WS   ACIX I 2nd WS


  • To elaborate concepts, protocols and guidelines for the inter-comparison and validation of BOA products
  • To better understand BOA reflectance uncertainty contributors by comparing the outputs of different AC schemes
  • To identify and review the different uncertainty contributors
  • To propose further improvements of the available AC schemes

Expected Outcomes

  • Description of concept, protocols and procedures for inter-comparing and validating products
  • Assessment of the relative differences among the inter-compared AC processors results
  • Definition of key regions and key periods for validation and quality assessment
  • Description of a coordinated plan for inter-comparison and validation activities



Scientific Publication

The description of the exercise and a summary of the results is available in:

Doxani, G.; Vermote, E.; Roger, J.-C.; Gascon, F.; Adriaensen, S.; Frantz, D.; Hagolle, O.; Hollstein, A.; Kirches, G.;Li, F.; Louis, J.; Mangin, A.; Pahlevan, N.; Pflug, B.; Vanhellemont, Q. "Atmospheric Correction Inter-Comparison Exercise." Remote Sens. 2018,10,352. doi:10.3390/rs10020352