Planning for a spaceborne Earth Observation mission: From user expectations to measurement requirements

This paper outlines the preparatory scientific activities that should precede and accompany the design and development of a spaceborne instrument for Earth Observation (EO), to guarantee fitness for purpose, ensure quality and performance, and minimize risks. This roadmap is addressed to policy and decision makers, program managers, customers and users of remote sensing products, as well as scientists involved in this field, and aims to provide the necessary background and motivation for the many steps and processes that are necessary to conduct a successful spaceborne EO mission. The paper focuses on, and is limited to, the description of a comprehensive, ideal methodology; it does not address the needs of a particular mission, or the engineering processes of design and development of the satellite hardware that will meet the user expectations. It should prove useful for the competent authorities to understand the scope and purpose (as well as the reasons for the associated implied costs) of preparatory phases, for the users and customers to express their expectations in ways that are conducive to the definition of a spaceborne EO mission, and for the scientific community to logically derive measurement requirements that are actionable by engineers to design and implement a successful mission (including both space and ground segments) that delivers relevant remote sensing products to the users.