Task Objective: Establish current state-of-the-art (SOA) for antenna arraying technologies for ground and spacecraft systems. Provide independent assessments to the SCaN Program, of emerging
technologies applied to NASA DSN and NASA ground networks.
The study will investigate total link budget losses, specifically
due to phase errors along the transmission path, ground-to-space
(uplink arraying) and on near earth-to-space/near earth-to-ground
(satellite arraying), by using a common, robust technique for real-time
phase compensation. Phase errors associated with thermal effects,
position determination, tropospheric effects, power equalization,
modulation techniques, schedule conflicts, coding techniques and
tracking and pointing will be addressed. Cost, operations flexibility, and reliability Synthesized large-equivalent apertures may be much less expensive if made up of smaller (and much lower-cost) unit elements, potentially resulting in a greater than an order of magnitude decrease in cost (e.g., less required elements for uplink, reduced power margin). Key capability presently unsupportable given the current communications infrastructure An array of smaller antennas can enable an operational concept whereby only the number of antennas necessary to support data reception for a given mission need be used for that purpose, freeing the other antennas to be used for other purposes (multi-beamforming capability). Improved failure modes using an arrayed aperture Although the risk is still present, systems failure tends to be softer than for an equivalent monolithic antenna (graceful degradation of performance vs. single-point failure). Human exploration missions possible with 99% availability Manned mission, critical high data rate uplinks are implementable through successful implementation of Ka-band transmit arraying. This includes operations during planetary exploration (using DSN arraying) and reduction of communications blackouts during launch (using TDRSS arraying). Technical Approach: Understand and independently validate proposed technologies, techniques, and experiments Develop and maintain the capability to provide independent assessments for future Ka-band architectures Develop SOA analytical capability for analyzing the performance of distributed ground and spacecraft antenna systems for the Ka-band. |
The focus of this effort is on Ka-band transmit antenna arraying.
The adaptive beamforming technique will be equally applicable to
the Deep Space Network (DSN) and to the Space Network (i.e. TDRSS).
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