Vibration monitoring of a hydroelectric power generation unit: Improved indicators of rotor health based on orbital analysisAlessandro Paolo Daga, Luigi Garibaldi, Damiano Cuvato, Manuel Bonjean, Antonino Sannolo and Lorenzo ArtazMechanics & Industry, 23 (2022) 15DOI: https://doi.org/10.1051/meca/2022016