Patent ID: 8498828

Claim:
A calculating device comprising: a first Fourier transform portion performing a Fourier transform on a first inputted signal; a second Fourier transform portion performing a Fourier transform on a second inputted signal; a complex conjugate deriving portion deriving a complex conjugate of the value outputted from the first Fourier transform portion; a multiplier multiplying the complex conjugate by the value outputted from the second Fourier transform portion, and for outputting the value after the multiplication; a Hilbert transform portion performing a Hilbert transform on the value after the multiplication; a first inverse Fourier transform portion performing an inverse Fourier transform on the value after multiplication; a second inverse Fourier transform portion performing an inverse Fourier transform on the value outputted from the first inverse Fourier transform portion; a phase relationship deriving portion deriving a phase relationship between the first inputted signal and the second inputted signal based on the value outputted from the first inverse Fourier transform portion and the value outputted from the second inverse Fourier transform portion; and a time difference deriving portion deriving the time difference between the first inputted signal and the second inputted signal based on the phase relationship.