A low-cost satellite terminal for measuring Ka-band propagation to low earth orbit using the CASSIOPE satellite

Although Ka-band links to communication satellites in geostationary orbit (GEO) have been used for many years, their use in communicating with communication and remote sensing satellites in low earth orbit (LEO) is still emerging. Of particular interest to designers is characterization of the rate of fading, i.e., the so-called fade slope, which is accentuated on links to satellites to LEO by the rapid manner in which the Earth-space path sweeps though rain cells in the vicinity of the Earth station as the satellite passes across the sky. Fade slopes steepen as the orbital altitude of the satellite decreases and as the intensity of individual rain cells increases. The result has important implications for the design of the power control loops and other mitigation strategies used to mitigate rain fading on such links. Only a few satellites in LEO carry Ka-band propagation beacons or receivers suitable for use in propagation studies and, for various reasons, relatively little measurement data to support design of such links is available.