  We introduce the notion of fault-tolerant quantum metrology to overcome noise
beyond our control -- associated with sensing the parameter, by reducing the
noise in operations under our control -- associated with preparing and
measuring probes and ancillae. To that end, we introduce noise thresholds to
quantify the noise resilience of parameter estimation schemes. We demonstrate
improved noise thresholds over the non-fault-tolerant schemes. We use quantum
Reed-Muller codes to retrieve more information about a single phase parameter
being estimated in the presence of full-rank Pauli noise. Using only error
detection, as opposed to error correction, allows us to retrieve higher
thresholds. We show that better devices, which can be engineered, can enable us
to counter larger noise in the field beyond our control. Further improvements
in fault-tolerant quantum metrology could be achieved by optimising in tandem
parameter-specific estimation schemes and transversal quantum error correcting
codes.
