A report in the form of lecture slides summarizes the optical-communications program of NASA's Jet Propulsion Laboratory (JPL) and describes the JPL Optical Communications Telescope Laboratory (OCTL) and its role in the program. The purpose of the program is to develop equipment and techniques for laser communication between (1) ground stations and (2) spacecraft (both near Earth and in deep space) and aircraft. The OCTL is an astronomical-style telescope facility that includes a 1-m-diameter, 75.8-m-focal length telescope in an elevation/azimuth mount, plus optical and electronic subsystems for tracking spacecraft and aircraft, receiving laser signals from such moving targets, and transmitting high-power laser signals to such targets. Near-term research at the OCTL is expected to focus on mitigating the effects of atmospheric scintillation on uplinks and on beacon-assisted tracking of ground stations by stations in deep space. Near-term experiments are expected to be performed with retroreflector-equipped aircraft and Earth-orbiting spacecraft techniques to test mathematical models of propagation of laser beams, multiple-beam strategies to mitigate uplink scintillation, and pointing and tracking accuracy of the telescope.
This work was done by Keith Wilson of Caltech for NASA's Jet Propulsion Laboratory. For further information, access the Technical Support Package (TSP) free on-line at www.techbriefs.com/tsp under the Electronics/Computers category. NPO-30575
This Brief includes a Technical Support Package (TSP).
Research and Development in Optical Communications
(reference NPO-30575) is currently available for download from the TSP library.
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Overview
The document is a Technical Support Package from NASA, specifically focused on research and development in optical communications, as referenced in NPO-30575 of NASA Tech Briefs. It outlines the advancements and ongoing projects at the Jet Propulsion Laboratory (JPL) aimed at enhancing optical communication technologies for deep-space applications.
A significant emphasis is placed on the Optical Communications Telescope Laboratory (OCTL), which is designed to facilitate the development of optical communication systems. The OCTL features a 1-meter precision tracking telescope capable of tracking objects from 250 kilometers to deep space. This telescope is equipped with a coude optical path and seven mirrors coated for high optical transmission, allowing it to operate effectively in various atmospheric conditions, both day and night.
The document discusses the challenges posed by atmospheric conditions, particularly the effects of cloud cover and scintillation-induced fades on laser communication systems. Scintillation can degrade the performance of laser-beacon tracking systems, which are crucial for accurate command transmission to spacecraft. To address these challenges, the OCTL's early experiments will focus on developing strategies to mitigate the impact of scintillation on optical links.
Additionally, the document references past experiments, such as the Galileo Optical Experiment (GOPEX), which validated tracking capabilities using a 0.6-meter telescope. It highlights the importance of tracking, acquisition, and pointing technologies in ensuring reliable communication with spacecraft, particularly those operating at significant distances, such as Mars.
The document also includes a list of references that provide further insights into various aspects of optical communications, including scintillation statistics, performance evaluations of laser communication equipment, and the design of optical trains for space communication.
Overall, this Technical Support Package serves as a comprehensive overview of NASA's efforts in advancing optical communication technologies, detailing the infrastructure, challenges, and future directions of research in this critical area of aerospace technology. It aims to make the results of these developments accessible for broader technological, scientific, and commercial applications.
