Best Practice Protocol for the validation of Aerosol, Cloud, and Precipitation Profiles (ACPPV)
Creators: name: Amiridis, Vassilis
name: Marinou, Eleni
name: Hostetler, Chris
name: Koopman, Rob
name: Cecil, Daniel
name: Moisseev, Dmitri
name: Tackett, Jason
name: Groß, Silke
name: Baars, Holger
name: Redemann, Jens
name: Marenco, Franco
name: Baldini, Luca
name: Tanelli, Simone
name: Fielding, Mark
name: Janiskova, Marta
name: Tanaka, Τoshiyuki
name: O'Connor, Ewan
name: Fjaeraa, Ann Mari
name: Paschou, Peristera
name: Voudouri, Kalliopi Artemis
name: Ferrare, Richard
name: Burton, Sharon
name: Schuster, Gregory
name: Kato, Seiji
name: Winker, David
name: Shook, Michael
name: Bley, Sebastian
name: Haarig, Moritz
name: Floutsi, Athena Augusta
name: Wandinger, Ulla
name: Trapon, Dimitri
name: Pfitzenmaier, Lukas
name: Papagiannopoulos, Nikolaos
name: Mona, Lucia
name: Posselt, Derek
name: Mason, Shannon
name: Rennie, Michael
name: Benedetti, Angela
name: Hogan, Robin
name: Sogacheva, Larisa
name: Balis, Dimitris
name: Michailidis, Konstantinos
name: van Zadelhoff, Gerd-Jan
name: Nowottnick, Edward
name: Yorks, John
name: Mroz, Kamil
name: Donovan, David
name: L'Ecuyer, Tristan
name: Okamoto, Hajime
name: Sato, Kaori
name: Henderson, David
name: Nishikawa, Tomoaki
name: Barker, Howard
name: Cole, Jason
name: Qu, Zhipeng
name: Clerbaux, Nicolas
name: Nakajima, Takashi
name: Chase, Randy
name: Wolff, David
name: Landulfo, Eduardo
name: Kirstetter, Pierre-Emmanuel
name: Mather, Jim
name: Ohigashi, Tadayasu
name: Ryder, Claire
name: Tzallas, Vasileios
name: Tsikoudi, Ioanna
name: Tsekeri, Alexandra
name: Tsichla, Maria
name: Koutsoupi, Iliana
name: Kubota, Takuji
name: Siomos, Nikolaos
name: Takahashi, Nobuhiro
name: Horie, Hiroaki
name: Suzuki, Kentaroh
name: Mace, Jay
name: McLean, William
name: Borderies, Maria
name: Mangla, Rohit
name: Escribano, Jerónimo
name: Moradi, Isaac
name: Zhang, Jianglong
name: Juli, Rubin
name: Ikuta, Yasutaka
name: Marbach, Thierry
name: Bojkov, Bojan
name: Accadia, Christophe
name: Fougnie, Bertrand
name: Spezzi, Loredana
name: Bozzo, Alessio
name: Chimot, Julien
name: Jafariserajehlou, Soheila
name: Flament, Thomas
name: Mattioli, Vinia
name: Strandgren, Johan
name: Barlakas, Vasileios
name: Kollias, Pavlos
Publisher: name: Zenodo
Year: 2025

description: Validation activities are critical to ensure the quality, credibility, and integrity of Earth observation data. With the deployment of advanced active remote sensors in space, a clear need arises for establishing best practices in the field of cloud, aerosol and precipitation profile validation. This publication fulfills this need, by proposing common practices, capturing lessons learned from earlier missions. The ACPPV publication is a result of an international collaboration of 97 scientists from 58 Institutions and Space Agencies, reviewed and accepted by the CEOS Working Group for Calibration and Validation (action item CV-22-01). The approaches and recommendations included, cover a range of issues, including correlative site and instrument selection, data processing and quality control, campaign criteria, configurations, scenarios, collocation methods, suggestions on issues concerning scene representativeness, and intercomparison methodologies. Moreover, guidance on the statistical validation through intercomparison between satellite-based remote sensing observations, and on the near-real time validation through monitoring in an NWP data assimilation system are included. To this end, the scientific communities involved in past missions have reviewed lessons learned and identified areas where convergence on similar approaches is beneficial. Finally, existing gaps in our Cal/Val knowledge are summarized. Given the complexity and diversity of geophysical scenarios and retrievals of aerosol, cloud, and precipitation regimes, the ACPPV document is aimed at knowledge exchange and conveying lessons learned, rather than definitions on single and strict protocols that have been agreed upon in some other domains with fewer degrees of freedom.