Patent ID: 7573021

Claim:
A method for determining the distance from an optical sensor interrogation system to a fiber optical sensor optically coupled through a length of optical fiber to the interrogation system which comprises the steps of: (a) providing the sensor interrogation system with a swept wavelength optical source which can be operated at two or more different known scan rates; (b) scanning the swept wavelength optical source at a first known scanning rate and determining a first measured wavelength of the optical sensor at the first scan rate; (c) scanning the swept wavelength optical source at a second known scan rate and determining a second measured wavelength of the optical sensor at the second scan rate, wherein the first and second scan rates are different; (d) calculating the distance from the optical sensor interrogation system to the fiber optical sensor assuming that the actual wavelength from the optical sensor is the same for the first and second scans and employing the first and second known scan rates and the first and second measured wavelengths of the fiber optical sensor measured at the two different scan rates.