A method of monitoring a shaft system, said method comprising providing a shaft system with a rotating member with a magnetic sensor target, providing a sensor rigid measurement system with a magnetostrictive sensor proximate said rotating member sensor target while inhibiting a physical contact between said measurement system magnetostrictive sensor and said rotating member, providing an interrogation pulse generator, providing a waveform detector for receiving a returned magnetostrictive pulse waveform, providing a template waveform, outputting an interrogation pulse from said interrogation pulse generator, receiving a returned magnetostrictive pulse waveform, and comparing said received returned magnetostrictive pulse waveform with said template waveform to determine a return time of said returned magnetostrictive pulse waveform to magnetostrictively measure a characteristic of said rotating member to monitor a performance of said shaft system.