Adaptive observation strategies provide the opportunity to make supplementary observations at locations dependent upon the current state of the atmosphere. The role an inexact estimate of the current state of the atmosphere (i.e. error in the ``analysis'') plays in restricting adaptive observation strategies is investigated. It is demonstrated that the assimilation scheme, or more precisely, the magnitude of the resulting analysis error, is crucial in limiting the scope of application of dynamically based strategies.

Key words: adaptive observations, linearisation, data assimilation, analysis error