An optical frequency domain reflectometry (OFDR) system for measuring a parameter of a sensing light guide, the sensing light guide including a series of light guide segments at corresponding locations along a length of the sensing light guide, the system comprising: an optical interferometric interrogator to generate an optical interrogation signal for input to the sensing light guide; optical detection circuitry coupled to the optical interferometric interrogator, the optical detection circuitry for detecting optical interferometric measurement signals for the length of the sensing light guide; and data processing circuitry configured to: receive an interferometric measurement signal from the optical detection circuitry, generate, from the interferometric measurement signal, an interferometric measurement data set including interferometric measurement data corresponding to a subset of segments of the series of segments along the length of the sensing light guide (S 10, S31); transform the interferometric measurement data for each segment of the subset of segments from a delay domain to a spectral domain to generate a transformed interferometric measurement data set (S12, S32); determine, from at least a subset of the transformed interferometric measurement data set, phase information corresponding to at least one reflective event; identify a non-linear phase part of the phase information (S16, S38) corresponding to a time-varying signal caused by a time-varying disturbance to the sensing light guide; and subtract the non-linear phase part from the interferometric measurement data set to compensate the interferometric measurement data set for the time-varying signal caused by the time-varying disturbance to the sensing light guide to enhance the measurement of the parameter (S18, S20). an optical interferometric interrogator to generate an optical interrogation signal for input to the sensing light guide; optical detection circuitry coupled to the optical interferometric interrogator, the optical detection circuitry for detecting optical interferometric measurement signals for the length of the sensing light guide; and data processing circuitry configured to: receive an interferometric measurement signal from the optical detection circuitry, generate, from the interferometric measurement signal, an interferometric measurement data set including interferometric measurement data corresponding to a subset of segments of the series of segments along the length of the sensing light guide (S 10, S31); transform the interferometric measurement data for each segment of the subset of segments from a delay domain to a spectral domain to generate a transformed interferometric measurement data set (S12, S32); determine, from at least a subset of the transformed interferometric measurement data set, phase information corresponding to at least one reflective event; identify a non-linear phase part of the phase information (S16, S38) corresponding to a time-varying signal caused by a time-varying disturbance to the sensing light guide; and subtract the non-linear phase part from the interferometric measurement data set to compensate the interferometric measurement data set for the time-varying signal caused by the time-varying disturbance to the sensing light guide to enhance the measurement of the parameter (S18, S20). receive an interferometric measurement signal from the optical detection circuitry, generate, from the interferometric measurement signal, an interferometric measurement data set including interferometric measurement data corresponding to a subset of segments of the series of segments along the length of the sensing light guide (S 10, S31); transform the interferometric measurement data for each segment of the subset of segments from a delay domain to a spectral domain to generate a transformed interferometric measurement data set (S12, S32); determine, from at least a subset of the transformed interferometric measurement data set, phase information corresponding to at least one reflective event; identify a non-linear phase part of the phase information (S16, S38) corresponding to a time-varying signal caused by a time-varying disturbance to the sensing light guide; and subtract the non-linear phase part from the interferometric measurement data set to compensate the interferometric measurement data set for the time-varying signal caused by the time-varying disturbance to the sensing light guide to enhance the measurement of the parameter (S18, S20).