  The paper considers the design of a nonlinear dissipative impulsive observer
based on non-periodic discrete-time measurements. Sufficient conditions are
derived for (i) exponential convergence of the observer in absence of
measurement uncertainty, and (ii) input-to-state stability (ISS) with respect
to measurement uncertainty, by combining notions from impulsive and dissipative
systems theory. The conditions mainly include constraints on the minimum and
maximum time between measurements depending on system characteristics, the
correction gain and the desired ISS gain. A representative case example is used
to illustrate the theoretical assessments.
