Citation
Abstract
On 23 nights between October 30, 1995, and January 13, 1996, the JPL Table Mountain Facility (TMF) was the site of the ground stations of the Ground/Orbiter Lasercomm Demonstration (GOLD). These 0.6-m and 1.2-m telescopes acted as terminals in a bent-pipe optical communications link. This link went from the ground to an optical communications transceiver terminal on the Japanese Engineering Test Satellite (ETS-VI) and back to the ground. This article describes how the TMF supported this novel optical communications experiment. This experiment was a collaborative effort between JPL, NASA’s Deep Space Network (DSN), the Japanese National Aeronautics and Space Development Agency (NASDA), and the Japanese Communications Research Laboratory (CRL), which operates the ETS-VI. The 0.6-m telescope, in the coud¶e configuration, was used to uplink a 514-nm modulated laser to the transceiver on the ETS-VI communications satellite. The 1.2-m telescope, in the Cassegrain configuration, was used to detect an 830-nm diode laser signal downlinked from the ETS-VI terminal. The downlink was sent only if the uplink beam was detected. The uplink beam had to be kept within a box 5 arcsec on a side and centered on the position of the ETS-VI. This required that the 0.6-m telescope track the ETS-VI to a precision of §2 arcsec. The 1.2-m telescope was required to track to a precision of 4-5 arcsec because the downlink detector had an aperture with a 13-arcsec-diameter field of view. This article describes how the above tracking performance was met by both telescopes. Equipment designed for the experiment at the transmitter and receiver stations, acquisition methods, and software developed to support this project are discussed, as are experiments performed to establish the suitability of the TMF telescopes for this demonstration. This article discusses upgrades to the TMF electrical power system needed to support GOLD; mechanical, optical, and servo-control aspects of the transmitter and receiver; and problems encountered during telescope operation.
Details
- Volume
- 42-125
- Published
- May 15, 1996
- Pages
- 1–11
- File Size
- 176.1 KB