This book presents the basic concepts and recent developments of linear control problems with perturbations. The presentation concerns both continuous and discrete dynamical systems. It is self-contained and illustrated by numerous examples.From the contents: Notion of state observersObservabilityObservers of full-phase vectors for fully determined linear systemsFunctional observers for fully determined linear systemsAsymptotic observers for linear systems with uncertaintyObservers for bilinear and discrete systems
