  In quantum metrology quantum properties such as squeezing and entanglement
are exploited in the design of a new generation of clocks, sensors and other
measurement devices that can outperform their classical counterparts.
Applications of great technological relevance lie in the precise measurement of
parameters which play a central role in relativity, such as proper
accelerations, relative distances, time and gravitational field strengths. In
this paper we generalise recently introduced techniques to estimate physical
quantities within quantum field theory in flat and curved space-time. We
consider a bosonic quantum field that undergoes a generic transformation, which
encodes the parameter to be estimated. We present analytical formulas for
optimal precision bounds on the estimation of small parameters in terms of
Bogoliubov coefficients for single mode and two-mode Gaussian channels.
