A shape sensing system comprising: an optical fiber, the optical fiber including multiple first cores having a first thermal response and one or more second cores having a second thermal response, the first thermal response differing from the second thermal response, wherein the multiple first cores and the one or more second cores are helically wound along a length of the optical fiber, and wherein the one or more second cores are located at a different radius than the multiple first cores; and an interferometric measurement system comprising: interferometric detection circuitry configured to detect measurement interferometric pattern data associated with each of the multiple first cores and each of the one or more second cores for multiple different temperatures; data processing circuitry (20, 22) configured to calibrate the optical fiber by: determining, based on the detected measurement interferometric pattern data, a matrix relating core responses to pitch, yaw, twist, tension, and temperature, the matrix including a temperature response of each core, and inverting the matrix; and a memory configured to store the inverted matrix for compensating subsequently obtained measurement interferometric pattern data for the optical fiber. an optical fiber, the optical fiber including multiple first cores having a first thermal response and one or more second cores having a second thermal response, the first thermal response differing from the second thermal response, wherein the multiple first cores and the one or more second cores are helically wound along a length of the optical fiber, and wherein the one or more second cores are located at a different radius than the multiple first cores; and an interferometric measurement system comprising: interferometric detection circuitry configured to detect measurement interferometric pattern data associated with each of the multiple first cores and each of the one or more second cores for multiple different temperatures; data processing circuitry (20, 22) configured to calibrate the optical fiber by: determining, based on the detected measurement interferometric pattern data, a matrix relating core responses to pitch, yaw, twist, tension, and temperature, the matrix including a temperature response of each core, and inverting the matrix; and a memory configured to store the inverted matrix for compensating subsequently obtained measurement interferometric pattern data for the optical fiber. interferometric detection circuitry configured to detect measurement interferometric pattern data associated with each of the multiple first cores and each of the one or more second cores for multiple different temperatures; data processing circuitry (20, 22) configured to calibrate the optical fiber by: determining, based on the detected measurement interferometric pattern data, a matrix relating core responses to pitch, yaw, twist, tension, and temperature, the matrix including a temperature response of each core, and inverting the matrix; and determining, based on the detected measurement interferometric pattern data, a matrix relating core responses to pitch, yaw, twist, tension, and temperature, the matrix including a temperature response of each core, and inverting the matrix; and a memory configured to store the inverted matrix for compensating subsequently obtained measurement interferometric pattern data for the optical fiber.