1. A computer-implemented method of determining an operational parameter of a machine, the method comprising: calculating an a priori estimated operational parameter of the machine based on a previously estimated operational parameter; determining whether a gear shifting is in progress; when the gear shifting is in progress, outputting the a priori estimated operational parameter as a determined operational parameter; and when the gear shifting is not in progress: measuring a measured operational parameter of the machine; calculating an a posteriori estimated operational parameter of the machine based on the a priori estimated operational parameter and the measured operational parameter; and outputting the a posteriori estimated operational parameter as the determined operational parameter.