e-CORCE : A SYSTEM PERSPECTIVE FOR A DAILY IMAGERY OF THE ENTIRE EARTH AT 1M RESOLUTION

摘要

e-CORCE covers a recent initiative launched by CNES concerning a future service that would provide a representation of the entire Earth with one meter resolution and daily update. The definition of the corresponding space system has to cope with several challenges, and implies many technico-economical trade-offs. THALES ALENIA SPACE has conducted under a CNES contract a system-level feasibility study aiming at defining a baseline solution for e-CORCE. The key technical themes of imagery chain, space segment, space ground telecommunications, and ground segment complexity for mission management and data processing were considered. The retained solution consists of: 1. a LEO-SSO constellation of minisatellites embedding instruments and dedicated resources allowing for wide swath, high resolution, and systematic imagery of the orbit lightened part ; 2. high rate transmission of data to a set of interconnected ground stations, with optimised locations and resources with regards to data management needs : reception, exchange, processing, and broadcasting. The present paper details a possible physical and functional architecture for e-CORCE, and its performance. Major trade-offs are addressed : imaging chain (image quality, instrument), constellation (constellation sizing, satellite class), telecom (telecommunication architecture), and ground segment (number and location of stations, ground segment complexity). Preliminary development elements, are also provided.