Characterization and modeling of point spread function in push-broom hyperspectral imaging systems for spectral and spatial resolution enhancement

Abstract

Push-broom hyperspectral imaging system ideally disperses the spectral and spatial information in two orthogonal directions preferably aligned with the columns and rows of the imaging sensor. Due to the imperfections in the camera lens and in particular the optical components of spectrograph, wavelength dependent spectral and spatial distortions along with spatial and spectral blur are introduced in the recorded image. In this study, we propose and evaluate a novel method for characterization and resolution enhancement of push-broom hyperspectral imaging systems. First, the spatially and spectrally dependent response function is characterized by measuring the response of the system to spectral and spatial reference objects. The relevant variability of the response function in the imaging plane is captured by a global parametric model. Finally, the response function estimate is used to remove distortions and enhance the spectral and spatial resolution of the system. The resolution enhancements were assessed by observing the change in full width at half-maximum of spectral response function and rise width of the spatial response function. The results of validation show that the proposed method affectively removes geometric distortions and significantly enhances the spectral and spatial resolution of the recorded images.