Browsing Space, Telecommunication, Astronomy, & Radiation Lab by Title
Now showing items 5-24 of 34
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Characterization of a semidiurnal eastward-propagating tide at high northern latitudes with Mars Global Surveyor electron density profiles
(American Geophysical Union, 2007-08-03)Apparent phase velocities of zonal structure, estimated from Mars Global Surveyor (MGS) electron density profiles, are used to identify and characterize SE1, the semidiurnal eastward-propagating tide with zonal wave number ... -
Combining laser frequency combs and iodine cell calibration techniques for Doppler detection of exoplanets
(SPIE - The International Society for Optical Engineering, 2010)Exoplanets can be detected from a time series of stellar spectra by looking for small, periodic shifts in the absorption features that are consistent with Doppler shifts caused by the presence of an exoplanet, or multiple ... -
Communication satellite power amplifiers: current and future SSPA and TWTA technologies
(Wiley, 2016-04)This study captures the state of current satellite transponder technology, specifically, solid-state power amplifiers (SSPAs) and traveling wave tube amplifiers (TWTAs), and describes expected future advances, including ... -
CubeSat deformable mirror demonstration
(SPIE - The International Society for Optical Engineering, 2012)The goal of the CubeSat Deformable Mirror Demonstration (DeMi) is to characterize the performance of a small deformable mirror over a year in low-Earth orbit. Small form factor deformable mirrors are a key technology needed ... -
Design of the Deformable Mirror Demonstration CubeSat (DeMi)
(Proc SPIE, 2017-09)The Deformable Mirror Demonstration Mission (DeMi) was recently selected by DARPA to demonstrate in-space operation of a wavefront sensor and Microelectromechanical system (MEMS) deformable mirror (DM) payload on a 6U ... -
Direct imaging of exoEarths embedded in clumpy debris disks
(SPIE - The International Society for Optical Engineering, 2012)The inner solar system, where the terrestrial planets formed and evolve, is populated by small grains of dust produced by collisions of asteroids and outgassing comets. At visible and infrared wavelengths, this dust cloud ... -
Effect of Longitude-Dependent Cloud Coverage on Exoplanet Visible Wavelength Reflected-Light Phase Curves
(IOP Publishing, 2015-05-10)We use a planetary albedo model to investigate variations in visible wavelength phase curves of exoplanets. Thermal and cloud properties for these exoplanets are derived using one-dimensional radiative-convective and cloud ... -
End-to-end simulation of high-contrast imaging systems: methods and results for the PICTURE mission family
(SPIE, 2015-09)We describe a set of numerical approaches to modeling the performance of spaceflight high-contrast imaging payloads. Mission design for high-contrast imaging requires numerical wavefront error propagation to ensure accurate ... -
Exoplanet Albedo Spectra and Colors as a Function of Planet Phase, Separation, and Metallicity
(The Astrophysical Journal, 2010-11-20)First generation space-based optical coronagraphic telescopes will obtain images of cool gas- and ice-giant exoplanets around nearby stars. Exoplanets lying at planet-star separations larger than about 1 AU—where an exoplanet ... -
First results on a new PIAA coronagraph testbed at NASA Ames
(SPIE - The International Society for Optical Engineering, 2009-01-01)Direct imaging of extrasolar planets, and Earth-like planets in particular, is an exciting but difficult problem requiring a telescope imaging system with 1010 contrast at separations of 100 mas and less. Furthermore, the ... -
Implementation and validation of a CubeSat laser transmitter
(SPIE, 2016)The paper presents implementation and validation results for a CubeSat-scale laser transmitter. The master oscillator power amplifier (MOPA) design produces a 1550 nm, 200mW average power optical signal through the use of ... -
Interplanetary space weather effects on Lunar Reconnaissance Orbiter avalanche photodiode performance.
(Space Weather: The International Journal of Research & Applications, 2016)Space weather is a major concern for radiation-sensitive space systems, particularly for interplanetary missions, which operate outside of the protection of Earth's magnetic field. We examine and quantify the effects of ... -
Interpolation Method for Update with Out-of-Sequence Measurements: The Augmented Fixed-Lag Smoother
(American Institute of Aeronautics and Astronautics, 2016-11)In this study, the authors propose a novel method to handle OOSMs in Kalman filtering. The proposed method, called the augmented fixed-lag smoother (AFLS), is based on the fixed-lag smoother (FLS) formulation, which has ... -
Laser Beacon Tracking for High-Accuracy Attitude Determination
(29th Annual AIAA/USU Conference on Small Satellites, 2015-08)CubeSat pointing capabilities have greatly improved in the past few years, paving the way for more sophisticated science and technology demonstration missions. Advances in attitude determination have led to the development ... -
Laser-Guide-Star Satellite for Ground-Based Adaptive Optics Imaging of Geosynchronous Satellites
(Journal of Spacecraft & Rockets, 2017-05)In this study, the feasibility and utility of using a maneuverable nanosatellite laser guide star from a geostationary equatorial orbit have been assessed to enable ground-based, adaptive optics imaging of geosynchronous ... -
Mars atmospheric CO2 condensation above the north and south poles as revealed by radio occultation, climate sounder, and laser ranging observations
(Journal Of Geophysical Research-Planets, 2012-07-10)We study the condensation of CO2 in Mars' atmosphere using temperature profiles retrieved from radio occultation measurements from Mars Global Surveyor (MGS) as well as the climate sounding instrument onboard the Mars ... -
Nonlinear Optics for Frequency-Doubling in Nanosatellite Laser Communication
(Utah State University Digital Commons, 2016-08-10)Free-space optical communication attracts interest due to its promise of higher data rates for similar size, weight, and power costs compared with radio systems. However, while satellite-to-ground optical communication has ... -
Physical characteristics and occurrence rates of meteoric plasma layers detected in the Martian ionosphere by the Mars Global Surveyor Radio Science Experiment
(American Geophysical Union, 2008-12-30)Low-altitude plasma layers are present in 71 of 5600 electron density profiles from the Martian ionosphere obtained by the Mars Global Surveyor Radio Science experiment. These layers are produced by the ablation of meteoroids ... -
Planetary Imaging Concept Testbed Using a Recoverable Experiment-Coronagraph (PICTURE C)
(SPIE, 2015)An exoplanet mission based on a high-altitude balloon is a next logical step in humanity's quest to explore Earthlike planets in Earthlike orbits orbiting Sunlike stars. The mission described here is capable of spectrally ... -
Quantifying the average and the likelihood of increases in space weather indices and in situ measurements during Solar Cycles 20–23
(International Journal of Space Science and Engineering, 2013-01)It is known that space weather harshly affects spacecraft performance, yet spacecraft operations and understanding the cause of anomalies can be challenging due to the complexity of environmental metrics. In this work, we ...