The Community Cloud retrieval for Climate (CC4CL). Part I: A framework applied to multiple satellite imaging sensors by Sus, O, Stengel, M, Stapelberg, S, McGarragh, GR, Poulsen, C, Povey, AC, Schlundt, C, Thomas, G, Christensen, M, Proud, S, Jerg, M, Grainger, R, Hollmann, R