This report presents the results of dynamic monitoring test carried out at a jacket-type offshore platform. The dynamic measurements consisted of vibration measurements with high accuracy equipment in twelve different positions located on the decks of the structure. The source of excitation was solely the ambient vibration by waves, wind and equipment on the structure under normal operation conditions. A large amount of measured data were analysed by advanced digital signal analysis techniques, followed by the extraction of structural modes. Then, a updated numerical model of the structure...