Persistency of excitation for nonminimal models of systems having purely deterministic disturbances

All results to date on the question of persistency of excitation depend on the model being minimal. Thus the results do not apply to systems having purely deterministic disturbances since these automatically give rise to uncontrollable modes on the unil circle. This note presents new results on persistency of excitation applicable to nonminimal models of systems having purely deterministic disturbances.