SAR Mission Planning for ERS-1 and ERS-2 Sergio D’Elia, Simon Jutz sdelia@esrin.esa.it sjutz@esrin.esa.it ESA / ESRIN Abstract: This paper presents the Mission Planning activities performed at ESRIN for the Synthetic Aperture Radar instruments on board of ERS-1 and ERS-2. A brief description of the Ground Segment (from user interface to data provision), of the Mission constraints and of the planning tools, introduces to the experience made in planning one satellite at a time and both in “Tandem”. The influence in mission planning of user expectations, special user requests, conflicts among user requests, conflicts with other sensors, addition of a “Baseline Plan”, practical ground segment constraints (very much different from the anticipated ones), parallel planning of ERS-1 and ERS-2, interference with other missions, etc. are all analysed and the implemented solutions are described. The experience gained can be used for future missions in the identification of the really achievable mission objectives, in the definition of the offer to the user, in the design of the Mission Planning system with particular attention to user and mission planner interface, in the preparation of agreements with the acquisition stations, etc.