We consider a worst case robust control oriented identification proble
m recently studied by several authors. This problem is one of H(i)nfin
ity identification in the continuous time setting. We give a more gene
ral formulation of this problem: The available a priori information in
this paper consists of a lower bound on the relative stability of the
plant, a frequency dependent upper bound on a certain gain associated
with the plant, and an upper bound on the noise level. The available
experimental information consists of a finite number of noisy plant po
int frequency response samples. The objective is to identify, from the
given a priori and experimental information, an uncertain model that
includes a stable nominal plant model and a bound on the modeling erro
r measured in H-infinity norm. Our main contributions include both a n
ew identification algorithm and several new 'explicit' lower and upper
bounds on the identification error. The proposed algorithm belongs to
the class of 'interpolatory algorithms' which are known to possess a
desirable optimality property under a certain criterion. The error bou
nds presented improve upon the previously available ones in the aspect
s of both providing a more accurate estimate of the identification err
or as well as establishing a faster convergence rate for the proposed
algorithm.