Citation
Abstract
The Optical Communications Telescope Laboratory (OCTL) to Optical Inter-orbit Engineering Test Satellite (OICETS) Optical Link Experiment (OTOOLE) is a joint Jet Propulsion Laboratory (JPL), National Institute of Information and Communications Technology (NICT), and Japanese Aerospace Exploration Agency (JAXA) bidirectional link (2.048 Mb/s uplink and 49.3724 Mb/s downlink) demonstration between the JPL OCTL ground station and the JAXA OICETS satellite. Located in the San Gabriel Mountains of Southern California, the OCTL houses a 1-m elevation/azimuth coudé-mount telescope co-aligned with a 20-cm acquisition telescope. The telescope tracks orbiting satellites as low as 250 km and slews at a maximum rate of 20 deg/s in azimuth and 10 deg/s in elevation, and can readily track the 601-km altitude OICETS satellite. This article describes the objectives, plans, and preparations for the OTOOLE demonstration. It describes the multibeam beacon and communications uplink design to mitigate the effects of atmospheric scintillation — four 801-nm beacon lasers arranged around the telescope primary at separations greater than the Fried coherence length. At 4 W average optical power, the beacons are transmitted in a 2-mrad divergent beam to compensate for satellite position uncertainty and telescope pointing errors. The communications uplink is a binary pulse position modulation format and consists of three laser beams also separated on the primary mirror by greater than the Fried coherence length. The total average power is 60 mW and the beam divergence is 1 mrad. OTOOLE experiments began on May 12, 2009, when the satellite’s orbit put it in high-elevation terminator passes over the OCTL.
Keywords
Details
- Volume
- 42-177
- Published
- May 15, 2009
- Pages
- 1–12
- File Size
- 447.4 KB