Engineering topics
Wilson, K.
Publications and source records attributed to Wilson, K..
Plans for a STRV-2 to AMOS High Data Rate Bi-directional Optical Communications Link
BMDO (Ballistic Missile Defense Organization) has developed a high-data rate (155Mbps - 1 Gbps) optical communications terminal that will be flown on the STRV-2 (space technology research vehicle) satellite.
Remote Sensing High Data Rate End-to-End System Architecture Trades
Explore the source record for details and available documents.
Optical Communication Demonstration and High-Rate Link Facility
Motivated by demands for faster, better, cheaper spacecraft, NASA is developing deep-space optical communication technology which promises reduced mass, volume, and power consumption compared to radiofrequency technology.
Progress in Design and Construction of the Optical Communications Laser
The deployment of advanced hyperspectral imaging and other Earth sensing instruments on board Earth observing satellites is driving the demand for high-data-rate communications.
Lasercom Test and Evaluation Station (LTES) Development: an update
Pre-launch integrated system characterization of a lasercom terminal's (LCT's) communications and acquisition/tracking subsystems can provide a quantitative evaluation of the terminal and afford a better rigorous assessment of the benefits of any demonstration.
High-Rate Optical Communications Links for Virtual Presence in Space
As man continues the exploration of space, either from platforms in Earth-orbit or from missions to the bodies of our solar system, there will be an on-going need to keep the public engaged in the process so that the general populace can share in the excitement of discovery and the inquisitive (professional or student) can participate in the data mining.
Reduction of ETS-VI Laser Communication Equipment Optical-Downlink Telemetry Collected During GOLD
Free-space laser communications experiments were conducted between the laser communication equipment (LCE) on board the Japanese Engineering Test Satellite VI (ETS-VI) and the ground station located at the Table Mountain Facility (TMF) during late 1995 and early 1996. This article describes the on-line data reduction process used to decode LCE telemetry (called E2) downlinked on the optical carrier during the Ground/Orbiter Lasercomm Demonstration (GOLD) experiments. The LCE has the capability of transmitting real-time sensor and status information at 128 kbps by modulating the onboard diode laser. The optical downlink was detected on the ground, bit synchronized, and the resulting data stream stored on a data recorder. The recorded data were subsequently decoded by on-line data processing that included cross-correlation of the known telemetry data format and the downlink data stream. Signals obtained from the processing can be useful not only in evaluating the characteristics of the LCE but also in understanding uplink and downlink signal quality.
Results From Phase-1 and Phase-2 GOLD Experiments
The Ground/Orbiter Lasercomm Demonstration conducted between the Japanese Engineering Test Satellite (ETS-VI) and the ground station at JPL's Table Mountain Facility, Wrightwood, California, was the rst ground-to-space two-way optical communications experiment. Experiment objectives included validating the performance predictions of the optical link. Atmospheric attenuation and seeing measurements were made during the experiment, and data were analyzed. Downlink telemetry data recovered over the course of the experiment provided information on in-orbit performance of the ETS-VI's laser communications equipment. Biterror rates as low as 10 4 were measured on the uplink and 10 5 on the downlink. Measured signal powers agreed well with theoretical predictions.
Comparative Study of Optical and Radio-Frequency Communication Systems for a Deep-Space Mission
We have performed a study on telecommunication systems for a hypothetical mission to Mars. The objective of the study was to evaluate and compare the benefits that microwave-X-band (8.4 GHz) and Ka-band (32 GHz) - and optical communications technologies a afford to future missions. The telecommunication systems were required to return data after launch and in orbit at 2.7 AU with daily data volumes of 0.1, 1.0, or 10.0 Gbits (Gb). Spacecraft terminals capable of delivering each of the three data volumes were proposed and characterized in terms of mass, power consumption, size, and cost. The estimated parameters for X-band, Ka-band, and optical frequencies are compared and presented here. For all cases, the optical light terminal exhibits about 60 percent of the mass of the corresponding radio frequency (RF) subsystem. Power consumption is comparable for all three technologies at a 0.1 Gb/day data volume, but the power required at either Ka-band or optical is less than half of the X-band requirement at 10 Gb/day. These benefits can be obtained only with a suitable investment in reception facilities for Ka-band or optical frequencies.
Data Analysis Results From the GOLD Experiments
Analyses of uplink and downlink data from recent free-space optical communications experiments carried out between Table Mountain Facility (near Pasadena, CA) and the Japanese ETS-VI satellite are presented.
Comparative Study of Optical and RF Communication Systems for a Mars Mission
We have performed a study on telecommunication systems for a hypothetical mission to Mars. The objective of the study was to evaluate and compare the benefits that microwave (X-band and Ka-band) and optical communications technologies afford to future missions.
Comparative Study of Optical and RF Communication Systems for a Mars Mission - Part II. Unified Value Metrics
In this Par-II report of the Advanced Communications Benefits study, two critical metrics for comparing the benefits of utilizing X-band, Ka-band and Optical frequencies for supporting generic classes of Martian exploration missions have been evaluated.
Effect of Aperture Averaging on a 570 Mbps 42 km Horizontal Path Optical Link
Optical communications offers high data rate satellite to ground communications in a small, low mass, and low power consumption package.
An Overview of the Compensated Earth-Moon-Earth Laser Link (CEMERLL) Experiment
Adaptive optics can mitigate the turbulence-induced wavefront distortions that limit the minimum practical beam divergence in a ground-to-space optical link, and enable high intensity laser beam propagation through the atmosphere. The CEMERLL experiment will use laser guide star adaptive optics to transmit a near-diffraction-limited laser beam from the Starfire Optical Range to the Apollo lunar retro-reflectors. The experiment will validate theoretical models that predict the effect of atmospheric turbulence on uncompensated and compensated laser beam propagation, and explore strategies to compensate for atmosphere-induced wavefront tilt not corrected for by laser guide star adaptive optics.
An Overview of the Compensated Earth-Moon-Earth Retroreflector Laser Link (CEMERLL) Experiment
The requisite SNR for optical beacons or uplink command signals sent to deep space probes can be achieved by either developing high repetition rate high peak power lasers and associated high-damage-threshold optical components or by propagating near-diffraction-limited beams to the spacecraft.