Panel a: angular velocity of a satellite as a function of its altitude, around Zenith; panel b: again at Zenith, effect of the altitude on the apparent magnitude of the satellite, and on the effective magnitude accounting for trailing (with a seeing of 1 arcsec); panel c: angular velocity of a satellite as a function of its zenithal distance, for various altitudes; panel d: combining the effect of distance and trailing on the effective magnitude, showing no dependency with zenithal distance.