Engineering topics
Publications and source records attributed to Abbe, Brian.
The ACTS aeronautical experiments include these purposes: (1) To test the viability of speech/data transmission at: 2.4, 4.8, 9.6, and 64, kbps; (2) To test the viability of high rate transmissions at 512, and 768 kbps; and (3) To test the viability of high data rate transmissions to/from turbojet up to 384 bps.
The National Aeronautics and Space Administration (NASA) has been involved in the development.
System studies have been carried out over the past three years at the Jet Propulsion Laboratory (JPL) on digital audio broadcasting (DAB) via satellite. The thrust of the work to date has been on designing power and bandwidth efficient systems capable of providing reliable service to fixed, mobile, and portable radios. It is very difficult to predict performance in an environment which produces random periods of signal blockage, such as encountered in mobile reception where a vehicle can quickly move from one type of terrain to another. For this reason, some signal blockage mitigation techniques were built into an experimental DAB system and a satellite experiment was conducted to obtain both qualitative and quantitative measures of performance in a range of reception environments. This paper presents results from the experiment and some conclusions on the effectiveness of these blockage mitigation techniques.
A description of the two aeronautical mobile satellite experiments utilizing NASA's Advanced Communications Technology Satellite (ACTS) is presented. The low bit rate experiment is principally a Ka-band technology demonstration of a prototype 4.8 Kbps aeronautic mobile terminal employing three experimental active electronically steered arrays. The high bit rate experiment can demonstrate a 64 Kbps to 384 Kbps satellite link between a ground terminal and an aircraft.