Advanced Communications Technology Satellite (ACTS): four-yearsystem performance

摘要

The Advanced Communications Technology Satellite (ACTS) wasnconceived at the National Aeronautics and Space Administration (NASA) innthe late 1970s as a follow-on program to ATS and CTS to continue NASA'snlong history of satellite communications projects. The ACTS project setnthe stage for the C-band satellites that started the industry, and laternthe ACTS project established the use of Ku-band for video distributionnand direct-to-home broadcasting. ACTS, launched in September 1993 fromnthe Space Shuttle, created a revolution in satellite system architecturenby using digital communications techniques employing key technologiesnsuch as a fast hopping multibeam antenna, an on-board basebandnprocessor, a wide-band microwave switch matrix, adaptive rain fadencompensation, and the use of 900 MHz transponders operating at Ka-bandnfrequencies. This paper describes the lessons learned in each of the keynACTS technology areas, as well as in propagation investigations