An interferometric measurement system for measuring an optical fiber including at least three primary cores and at least two redundant cores, the interferometric measurement system comprising: interferometric detection circuitry configured to detect measurement interferometric pattern data associated with the at least three primary cores and the at least two redundant cores when the optical fiber is placed into a sensing position; and data processing circuitry configured to: calculate primary-core values based on a predetermined geometry of the at least three primary cores and the detected measurement interferometric pattern data associated with the at least three primary cores, the primary-core values comprising primary-core values of two fiber bend parameters and of a fiber strain parameter for the optical fiber, calculate redundant values based at least in part on a predetermined geometry of the at least two redundant cores and on the detected measurement interferometric pattern data associated with the at least two redundant cores, the redundant values comprising redundant values of the two fiber bend parameters and of the fiber strain parameter for the optical fiber, perform a comparison of the primary-core values and the redundant values of the two fiber bend parameters and of the fiber strain parameter, determine whether the primary-core values of the two fiber bend parameters and of the fiber strain parameter are reliable or unreliable based on the comparison, and in response to a determination that the primary-core values of the two fiber bend parameters and the fiber strain parameter are unreliable, causing: an indication of the primary-core values as unreliable, or a precautionary or protection action. interferometric detection circuitry configured to detect measurement interferometric pattern data associated with the at least three primary cores and the at least two redundant cores when the optical fiber is placed into a sensing position; and data processing circuitry configured to: calculate primary-core values based on a predetermined geometry of the at least three primary cores and the detected measurement interferometric pattern data associated with the at least three primary cores, the primary-core values comprising primary-core values of two fiber bend parameters and of a fiber strain parameter for the optical fiber, calculate redundant values based at least in part on a predetermined geometry of the at least two redundant cores and on the detected measurement interferometric pattern data associated with the at least two redundant cores, the redundant values comprising redundant values of the two fiber bend parameters and of the fiber strain parameter for the optical fiber, perform a comparison of the primary-core values and the redundant values of the two fiber bend parameters and of the fiber strain parameter, determine whether the primary-core values of the two fiber bend parameters and of the fiber strain parameter are reliable or unreliable based on the comparison, and in response to a determination that the primary-core values of the two fiber bend parameters and the fiber strain parameter are unreliable, causing: an indication of the primary-core values as unreliable, or a precautionary or protection action. calculate primary-core values based on a predetermined geometry of the at least three primary cores and the detected measurement interferometric pattern data associated with the at least three primary cores, the primary-core values comprising primary-core values of two fiber bend parameters and of a fiber strain parameter for the optical fiber, calculate redundant values based at least in part on a predetermined geometry of the at least two redundant cores and on the detected measurement interferometric pattern data associated with the at least two redundant cores, the redundant values comprising redundant values of the two fiber bend parameters and of the fiber strain parameter for the optical fiber, perform a comparison of the primary-core values and the redundant values of the two fiber bend parameters and of the fiber strain parameter, determine whether the primary-core values of the two fiber bend parameters and of the fiber strain parameter are reliable or unreliable based on the comparison, and in response to a determination that the primary-core values of the two fiber bend parameters and the fiber strain parameter are unreliable, causing: an indication of the primary-core values as unreliable, or a precautionary or protection action.