An Improved Algorithm for Fringe Jump Corrections with Three-classification Unwrapping for Far-infrared Interferometer

Line-averaged plasma electron density can be calculated by comparing the phase difference between probing signal and reference signal from the far-infrared interferometer. In the process, fringe jumps could result in incorrect data in reconstruction. In order to process the line-averaged plasma electron density signals on the Experimental Advanced Superconducting Tokamak (EAST), a new phase unwrapping algorithm by means of classification is proposed to extract density information from the phase difference, which can avoid and recover the fringe jumps in the whole process. The results showed that the improved algorithm has the advantages of real-time, high resolution, and high accuracy.