Bit error performance of selected CCSDS recommended bandwidth efficient modulations using the block V receiver
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Advanced semiconductor nanofabrication techniques are utilized to design, fabricate and demonstrate a super-compact, low-mass (<10 grams) submillimeter-wave heterodyne front-end. RF elements such as waveguides and channels are fabricated in a silicon wafer substrate using deep-reactive ion etching (DRIE). Etched patterns with sidewalls angles controlled with 1 deg precision are reported, while maintaining a surface roughness of better than 20 nm rms for the etched structures. This approach is being developed to build compact 2-D imaging arrays in the THz frequency range.
NASA's twin GRAIL [1] spacecraft (Ebb and Flow) arrived at Earth's Moon on New Year's Day, 2012. GRAIL's primary mission is to create a high-resolution map of the Moon's gravitational field by measuring very precisely the change in distance between the two spacecraft [2]. Each spacecraft transmits two signals to the other spacecraft, a PRN code modulated on a 2 GHz carrier (S-band), as well as an unmodulated carrier at roughly 33 GHz (Ka-band). Since it's not feasible to synchronize the two GRAIL spacecraft's clocks via GPS (as was done with GRACE), the S-band signals are used as a time-transfer link to synchronize either Ebb's clock to Flow or vice versa. As an independent measure to determine the clock offset of the GRAIL ultra-stable oscillators to UTC(NIST), an experiment was conducted where our JPL team used a large antenna on Earth to eavesdrop on the inter-spacecraft time-transfer link.
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The OH radical is an important player in known ozone depletion cycles; however, due to its location in the atmosphere, it must be studied from either a balloon or spaceborne platform.
We report on a subharmonic mixer with a broad IF bandwidth that has been developed for the Microwave Instrument for the Rosetta Orbiter (MIRO) to study water transition lines occurring near 557 GHz.
Operational use of GPS has been demonstrated half-way to the moon on the Magnetospheric Multiscale (MMS) mission. Lunar GNSS feasibility has been demonstrated through high fidelity simulations conducted by the Space Communications and Navigation (SCaN) program.
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