Figure 3: Basic DMA geometry: Example with a1D array. Top slit corresponds to a state of the art slit (aperture typically in a metallic membrane). The slit in the middle is an example of a smart slit, where certain parts of the scene/object are blocked. The slit below is a closed slit, for instance during commissioning to avoid direct sun-illumination reaching the detector or during detector frame transfer to reduce read-out noise.