Table 3 Parameters of the QKD model for a conservative source performance. Note that we consider two cases: \(\tau = 1~\mbox{ns}\) and \(\mu = 0.1\), corresponding to a pair production of \(10^{8}~\mbox{s}^{-1}\), and \(\tau = 200~\mbox{ps}\) and \(\mu = 0.06\), which corresponds to \(R_{\text{pair}} = 3 \cdot 10 ^{8}~\mbox{s} ^{-1}\)
From: Nanobob: a CubeSat mission concept for quantum communication experiments in an uplink configuration
q | basis reconciliation factor | 0.5 | |
f(E) | bidirectional error correction function | 1.22 | |
τ | coincidence time window | 1 (0.2) | ns |
μ | average number of photons per pulse | 0.1 (0.06) | |
\(D_{A}\) | OGS dark count rate per detector | 100 | cps |
\(D_{B}\) | satellite dark count rate per detector | ≥100 | cps |
B | satellite background count rate | 400 | cps |
\(N_{\mathrm{det}}\) | number of detectors | 4 | |
PDE | Photon Detection Efficiency of satellite single photon detectors [40] | 0.4 | |
\(T_{\mathrm{optics}}\) | satellite receiver optical transmission | 0.8 | |
\(\eta _{A}\) | OGS overall detection efficiency [44] | 0.6 | |
\(\eta _{B}\) | \(\eta _{B} = T_{\mathrm{optics}} \cdot \mbox{PDE} \cdot 10^{-A/10}\), with A the quantum channel link attenuation in dB | ||
\({e}_{0}\) | error probability of dark- and background counts | 0.5 | |
\({e}_{\mathrm{d}}\) | error probability of photon arriving on wrong detector (polarization error) | 0.01 |