Digital traffic capability, digital modems and digital baseband equipment. Phase II DSCS, IDCSP, PHASE I DSCS. increased effective radiated power (ERP) earth coverage and narrow beam antennas. synchronous orbits vs drifting nonsynchronous orbits. active satelittles act as repeater, amplify signal and re-transmits to earth. and passive satellites. reflect radio signnals back to earth. up-link frequency amplified and retransmitted on down-link frequency. synchronous orbit, asynchhronous orbit. Two earth terminals, military communication satellite. Ørbit Descriptions. saellites orbit in elliptical orbits determined by initial lauunch parameters. Perigee and apogee two of three parameters to describe orbital data of satellite. Preigee is point of orbit of a satellite that is nearest to the center of the earth. Apogee is the point of orbit of a satellite that is farthest from the center of the earth.
