A spectral imaging system includes an autocorrelator to generate different autocorrelations when the moving reflector in the autocorrelator is at different positions so as to reconstruct spectral images. The system also includes a position measurement system to measure the actual positions of the moving reflector when autocorrelations are taken. These actual locations, instead of the desired locations in conventional methods, are then used to reconstruct the spectral image. This approach can address the misalignment of the moving reflector from its desired location (due to external disturbances, slow actuator dynamics, and other factors) in conventional spectral imaging techniques and allow the development of high-resolution, high-stability, portable imaging spectrometers for the general public.