Articolo in rivista, 2023, ENG, 10.3390/atmos14030550

Towards Space Deployment of the NDSA Concept for Tropospheric Water Vapour Measurements

Facheris L., Antonini A., Argenti F., Barbara F., Cortesi U., Cuccoli F., Del Bianco S., Dogo F., Feta A., Gai M., Gregorio A., Macelloni G., Mazzinghi A., Melani S., Montomoli F., Ortolani A., Rovai L., Severin L., Scopa T.

Department of Information Engineering, University of Florence, 50139 Florence, Italy; National Inter-University Consortium for Telecommunications (CNIT), 43124 Parma, Italy; Istituto per la BioEconomia del Consiglio Nazionale delle Ricerche (IBE-CNR), 50019 Sesto Fiorentino, Italy; LaMMA Consortium, via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy; Istituto di Fisica Applicata Nello Carrara del Consiglio Nazionale delle Ricerche (IFAC-CNR), 50019 Sesto Fiorentino, Italy; Department of Physics, University of Trieste, 34127 Trieste, Italy; PICOSATS S.R.L., 34149 Trieste, Italy; ASI--Agenzia Spaziale Italiana, 00133 Rome, Italy

A novel measurement concept specifically tuned to monitoring tropospheric water vapour’s vertical distribution has been demonstrated on a theoretical basis and is currently under development for space deployment. The NDSA (Normalised Differential Spectral Attenuation) technique derives the integrated water vapour (IWV) along the radio link between a transmitter and a receiver carried by two LEO satellites, using the linear correlation between the IWV and a parameter called spectral sensitivity. This is the normalised incremental ratio of the spectral attenuation at two frequencies in the Ku and K bands, with the slope of the water vapour absorption line at 22.235 GHz. Vertical profiles of WV can be retrieved by inverting a set of IWV measurements acquired in limb geometry at different tangent altitudes. This paper provides a comprehensive insight into the NDSA approach for sounding lower tropospheric WV, from the theoretical investigations in previous ESA studies, to the first experimental developments and testing, and to the latest advancements achieved with the SATCROSS project of the Italian Space Agency. The focus is on the new results from SATCROSS activities; primarily, on the upgrading of the instrument prototype, with improved performance in terms of its power stability and the time resolution of the measurements. Special emphasis is also placed on discussing tomographic inversion methods capable of retrieving tropospheric WV content from IWV measurements, i.e., the least squares and the external reconstruction approaches, showing results with different spatial features when applied to a given atmospheric scenario. The ultimate goal of deploying the NDSA measurement technique from space is thoroughly examined and conclusions are drawn after presenting the results of an Observing System Simulation Experiment conducted to assess the impact of NDSA data assimilation on environmental model simulations.

Atmosphere (Basel) 14 (3), pp. Article number 550–?

Keywords

tropospheric water vapour, total column and vertical profile, active microwave sounding, Normalised Differential Spectral Attenuation, assimilation methods

CNR authors

Cortesi Ugo, Macelloni Giovanni, Ortolani Alberto, Melani Samantha, Del Bianco Samuele, Barbara Flavio, Gai Marco, Montomoli Francesco, Rovai Luca

CNR institutes

IFAC – Istituto di fisica applicata "Nello Carrara", IBE – Istituto per la BioEconomia

ID: 479135

Year: 2023

Type: Articolo in rivista

Creation: 2023-03-14 10:11:43.000

Last update: 2023-10-12 13:59:06.000

External IDs

CNR OAI-PMH: oai:it.cnr:prodotti:479135

DOI: 10.3390/atmos14030550

ISI Web of Science (WOS): 000955069700001

Scopus: 2-s2.0-85151367186