Numerical line of sight stabilisation for high resolution earth observation from high orbits

Controlling line of sight instabilities due to platform μ- vibrations is a major issue for High Orbits (HO) decametric and metric Earth Observation imaging systems. Indeed, as image quality is strongly impacted by such μ-vibrations during integration time, observation from HO requires a very high angular precision around tens of millirad over tens or even hundreds of milliseconds. This angular stability requirement is out of scope for conventional Attitude and Orbit Control System (AOCS). Two different solutions – post-accumulation and closed-loop control of the line of sight – are envisaged and discussed to deal with those μ-vibrations to make possible decametric or metric Earth Observation from High Orbits.