Wave heave sensor verification in dry conditions with optoelectronic reference

Sea state information is required for coastal engineering and safety of navigation. Inertial Measurement Units (IMUs) are playing an effective role in the estimation of the sea state in real time application also. In this paper, a novel method for heave inertial sensors verification in a dry environment is presented. The main peculiarity is that the IMU movement is measured through an optoelectronic external instrument, and not guaranteed by the mechanical assembly of the movement generation device. Furthermore, the generated movement presents reality aspects, such as oscillations of the sensors, that are not common in similar devices. The proposed approach has been tested considering a general purpose IMU, which requires a processing procedure to measure the heave. Two possible procedures based on different filtering approaches are proposed and compared. The test procedure enables a quantitative evaluation of the heave measurement by inertial sensors including the evaluation of measurement uncertainty in each test conditions.