Radiometric calibration method of MWIR spectrometer coded by Hadamard transform

Due to the poor manufacturing process of MWIR diffraction grating, there are obvious non working level diffraction images in MWIR imaging spectrometer which uses Hadamard Transform to realize the snapshot staring imaging. When non working level and working level diffraction images overlap in space, it becomes impossible to extract the MWIR spectrum information of targets. To solve this problem, an absolute radiation calibration method based on Hadamard Transform is proposed. The blackbody and collimator are used as input to code, calibrate and decode the target spectrum information. Then, the MWIR spectrum curve of targets can be obtained after decoding. Compared with the theoretical spectrum curve of the target, the relative error is less than 1%. The influence of diffraction image aliasing on the system is eliminated, which proves the feasibility of this method.