A Novel Method to Remove Interference Fringes for Hyperspectral SWIR Imagers

A hyperspectral short-wave infrared (SWIR) imager with a HgCdTe focal plane detector usually suffers from interference fringes in spectral and spatial dimension due to the etalon effect. It can cause a modulation of sensitivity higher than 15% when the spectral resolution is higher than 10 nm. In this article, a two-step method is proposed and evaluated to remove interference fringes for hyperspectral SWIR imagers. First, we extract the spectral data, conduct harmonic decomposition to suppress the fringes in spectral dimension, and calculate the correction coefficients. Second, we optimize the correction coefficients according to the distribution of the interference fringes in spatial dimension. Sample SWIR images acquired from the Advanced Hyperspectral Imager (AHSI) on China's GaoFen-5 satellite are used to evaluate the performance of the algorithm. It shows that the proposed method can well preserve the original spectral pattern and reduce the peak-to-peak amplitude of spatial fringing from ±15% to ±4%. The method is compared with three other previously proposed methods. It turns out that the newly proposed method has strong adaptability, high accuracy, and high efficiency.