Optimal Variables for Retrieval Products

The increase in satellite instruments sounding the atmosphere will increase the frequency of several instruments simultaneously measuring either the same vertical profile or vertical profiles related to nearby geo-locations, and users will consult fused products rather than individual measurements. Therefore, the retrieval products should be optimized for use in data fusion operations, rather than for the representation of the profile. This change in paradigm raises the question of whether a more functional representation of the retrieval products exists. New variables for the retrieval products are proposed that have several advantages with respect to the standard retrieval products. These variables, in the linear approximation of the forward model, are independent of the a priori information used in the retrieval, allow us to represent the profile with any a priori information and can be used directly to perform the data fusion of a set of measurements. Furthermore, the use of these variables allows us to reduce the stored data to about one third of its volume with respect to the use of standard retrieval products.