  In quantum metrology, the parameter estimation accuracy is bounded by quantum
Fisher information. In this paper, we present coherence measures in terms of
(quantum) Fisher information by directly considering the post-selective
non-unitary parametrization process. This coherence measure demonstrates the
apparent operational meaning by the exact connection between coherence and
parameter estimation accuracy. We also discuss the distinction between our
coherence measure and the quantum Fisher information subject to unitary
parametrization. The analytic coherence measure is given for qubit states.
