Title of Paper: Multi-Gigabit Data-rate Optical Communications
Depicting LEO-to-GEO and GEO-to-Ground Links
Principal Author: Dr. Hamid Hemmati
Abstract: The goal of this AIST-funded task is to develop
key components of the technology that will enable optical communications to
meet the data delivery requirements of the EOS community. A systems engineering
document that outlines the requirements followed by acquisition and tracking
scenarios, and communication link analysis was completed. The link analysis
identifies the telescope aperture sizes and the required beacon and transmit
laser power. Both LEO-to-GEO and GEO-to-Ground links have been considered. The
LEO-GEO link is considering a 1.24 Gbps data-rate link while the goal of the
GEO-Ground link is 10 Giga-bit-per-sec (Gbps) in a single or four 2.5 Gbps
channels.
The first year (of the two-year effort) focuses on communication link
demonstration in the laboratory and detailed analysis and planning for
acquisition, tracking and pointing. We are now developing the transmitter,
receiver and optical subsystems that constitute the breadboard. Current
emphasis is on a 2.5 Gbps link while the components are also being developed
for a 10 Gbps data-rate link.
The breadboard utilizes a 13 cm diameter telescope as transmit aperture,
simulating the LEO terminal. The receiver is a 30-cm all Silicon Carbide
telescope which simulates the GEO terminal. The objective of the laboratory
breadboard development is to demonstrate that the optical communications link
could be established efficiently as predicted by the link analysis programs.
The second year of the effort would concentrate on acquisition. Tracking and pointing strategies and a demonstration of tracking between two moving platforms depicting a LEO-to-GEO link.