Extension of the Complete Data Fusion algorithm to tomographic retrieval products

Abstract

In data analysis of atmospheric remote sensing, the combination of complementary measurements of the same atmospheric state from different sensors operating with different geometries and/or in different spectral ranges is a powerful technique to advance the knowledge of tropospheric and stratospheric processes. Complete data fusion (CDF) is an a posteriori method used so far to combine only one-dimensional (1D) atmospheric products (vertical profiles) related to the same or nearby geolocations from simultaneous and independent remote sensing observations. In this study, we demonstrate the applicability of the CDF algorithm to two-dimensional (2D) products and show its first application to simulated ozone datasets from the future Infrared Atmospheric Sounding Interferometer New Generation (IASI-NG) mission and the Changing-Atmosphere Infrared Tomography (CAIRT) ESA's Earth Explorer 11 candidate mission, in nadir-and limb-viewing observational geometry, respectively. We present the analysis of the performance of the CDF in three (one 1D and two 2D) case studies considering different configurations for the acquisitions of the two sensors, evaluating for each the number of degrees of freedom, the Shannon information content, the total errors and the spatial resolution. Furthermore, we quantitatively compare the 1D-CDF and 2D-CDF performances, demonstrating that the exploitation of tomographic capabilities of atmospheric sensors allows advanced data fusion techniques, like 2D CDF, to maximize the information extracted from complementary datasets.