and noise light flux). The experiment data for the CI protocol is obtained from the experiment data of the QTC protocol by neglecting the photon detection events on the reference detector (since CI could be treated as a special case of QTC with zero reference photon transmission). By doing so the experimental conditions of the QTC experiment and CI experiment are made sure identical. The variance of the transmission estimation as a function of varying probe light flux and noise light flux is shown in Fig. \[FI\_RESULT\]. The experimental result is in close agreement with the theoretical prediction of the Fisher information calculation. As can be seen, the performance enhancement of the QTC protocol is most pronounced in the high noise and low probe light flux regime, with the enhancement (defined as the ratio between the estimation variance for the QTC and CI protocol) as a function of noise, and probe light flux reaching up to 21.36 dB, 26.3 dB respectively. In the current implementation of the QTC protocol, one of the major performance limiting factor is the detector temporal resolution $\simeq 100$ps. The detector temporal resolution and the target detection performance can be (effectively) improved with better single-photon detection 