Speckles and their effects in spectrometers due to on-board diffusers

Earth observation satellites are commonly equipped with an on-board diffuser. Their use will be pointed out and the errors associated with their use will be explained. The origin of the errors, the speckles formed by scattering on the diffusers, will be dealt with in detail and solutions to minimize these errors will be presented. The use of diffusers, and the types of diffusers will be discussed in combination with their ability to minimise the contrast of the spectral features.