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The experiment of mobile communications and broadcasting by S-band and the satellite navigation by L/S-band are the main objectives of Engineering Test Satellite - 8 (ETS-8), which will be launced in 2004 into geostationary orbit at 146 degree East. In this paper, the current status of ETS-8 is introduced at first and the basic experiment plan is described. For the mobile communications/broadcasting, two deployable reflectors (17 meters × 19 meters, each) and a 400 W class active phased array feeder with 31 SSPAs are installed in ETS-8. Three beams are used simultaneously to cover Japan and neighbor region. Two kinds of onboard processors are also installed, which are dedicated to voice and high-speed packet communication, respectively. The ground terminal for voice communications is as small as conventional cellular phone, and that for packet is similar size of notebook type PC. For satellite navigation, two Cesium clocks are installed. The coverage area is Asia-Pacific hemisphere. The experiment will be conducted by use of ground stations and signals from GPS. The positioning accuracy is evaluated by changing RF frequency, code pattern and chip rate. To determine the precise orbital parameters of satellite, the laser ranging method is adopted. This satellite navigation experiment will be conducted in cooperation with foreign and domestic institutes. After the funtion tests of satellite in orbit, it will be from 2005 year, the opportunity to conduct some experiment used of ETS-8 will provide. The participation of those who have interest in these experiments is welcome. |
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