Table 1 Main parameters of the downlink and the uplink; the satellite is in a circular orbit at an altitude of 560 km
From: Vector—towards quantum key distribution with small satellites
Downlink | Uplink | ||
|---|---|---|---|
Wavelength, nm | 850 | 808 | |
Far-field divergence, μrad | 68 | ||
Aperture diameter of receiver, mm | 600 | 30 | |
Diffraction loss, dB | Zenith | 39.0 | 65.0 |
Elevation 20° | 46.4 | 72.4 | |
Scattering and absorption losses, dB | Zenith | 0.9–1.6 1 | |
Elevation 20° | 2.7–4.8 1 | ||
Loss due to pointing error, dB | 0.0 | 4.8 | |
Constant loss in the transmitter, dB | 0.7 | – | |
Constant loss in the receiver, dB | 7.1 2 | 0.3 | |
Total loss, dB | Zenith | 47.7–48.4 1 | 71.0–71.7 1 |
Elevation 20° | 56.9–59.0 1 | 80.2–82.3 1 | |