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Accelerating Space Commerce, Exploration, and New Discovery Conference, ASCEND 2020

作者： Tellier, Daniel Millman, Meyer McClelland, Brian Go, Kate Beatrix Balayan, Alice Munje, Michael J. Dewey, Kyle Ho, Nhut Havelund, Klaus Ingham, Michel Department of Computer Science California State University Northridge NorthridgeCA91330 United States Department of Electrical and Computer Engineering California State University Northridge NorthridgeCA91330 United States Department of Mechanical Engineering California State University Northridge NorthridgeCA91330 United States Laboratory for Reliable Software Jet Propulsion Laboratory California Institute of Technology PasadenaCA91109 United States Systems Engineering Division Jet Propulsion Laboratory California Institute of Technology PasadenaCA91109 United States

ISBN: (纸本)9781624106088

In space applications, hierarchical state machines (HSMs) are often used for writing simulation and control software, including that of the Curiosity rover. At the jet propulsion Lab (JPL), multiple programming languages have been developed specifically for writing HSM-based software, and these have been used in practice. However, we observe that the existing languages developed have significant issues with one or more of usability, performance, and safety, making them problematic for HSM-based development. To address these concerns, we are taking lessons learned from these languages and developing a new programming language named Proteus. Proteus builds HSM support directly into the language, and permits complex HSMs to be defined which communicate with each other. Proteus is designed with a look and feel similar to C/C++, making it usable and overall approachable for use by JPL systems engineers. Proteus itself compiles to C++, allowing it to fit easily into existing development toolchains, and making it amenable to embedded real-time systems. To ensure that Proteus will be of use to its target audience, it is being developed iteratively through a series of prototypes which are regularly evaluated by key stakeholders at JPL, allowing us to refine its design if we go off course. While Proteus is still very young in its development, we demonstrate its basic viability on an example utilizing multiple independent HSMs communicating with each other, and relevant execution traces. In the future, we plan to apply Proteus to larger HSMs taken from real space applications, and many additional relevant features are planned. © 2020 The MITRE Corporation. All Rights Reserved.

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Processes Underlying the Year-To-Year Fluctuations of the Global Mean Surface Temperature

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Atmospheric Science Letters 2025年第6期26卷

作者： Angela Jiang Jonathan H. Jiang Bin Guan Arcadia High School Arcadia California USA Jet Propulsion Laboratory California Institute of Technology Pasadena California USA Joint Institute for Regional Earth System Science & Engineering University of California Los Angeles California USA

In addition to the global mean surface temperature (GMST), accurately predicting regional features associated with GMST changes is essential for effective climate policymaking at the regional level. This study investigates regional patterns of surface temperature and precipitation associated with interannual GMST variability and evaluates their representation in state-of-the-art climate models. Although the influence of the El Niño-Southern Oscillation (ENSO) on GMST variability is well recognized, it accounts for less than 50% of the total interannual variability. A significant portion of GMST warming, independent of ENSO, is closely associated with widespread regional warming—most notably over North America—along with increased atmospheric river activity and enhanced precipitation along its west coast. However, current climate models systematically underestimate the ENSO-independent component of GMST variability, thereby introducing uncertainties into our interpretation of GMST changes.

关键词： climate prediction El Niño-southern oscillation global mean surface temperature interannual variability

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Direct numerical simulation of fog formation within the surface layer 22

Direct numerical simulation of fog formation within the surf...

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22nd Australasian Fluid Mechanics Conference, AFMC 2020

作者： MacDonald, Michael Kurowski, Marcin J. Teixeira, João Department of Mechanical Engineering The University of Auckland Auckland1010 New Zealand Jet Propulsion Laboratory California Institute of Technology PasadenaCA91109 United States Joint Institute for Regional Earth System Science and Engineering University of California Los Angeles Los AngelesCA90095 United States

ISBN: (纸本)9781742723419

We investigate the effects of shear-driven turbulence on fog formation in the stably stratified surface layer, using recent direct numerical simulations (DNS) of dry and moist open-channel flows. A constant cooling rate applied at the ground mimics longwave radiative cooling, leading to either turbulent (weakly stable) or laminar (very stable) flows. The transition of the Obukhov, Ozmidov and buoyancy length scales are investigated for different cooling rates and Reynolds numbers. Compared to the dry case, the condensation of liquid water in the moist case supports slightly higher cooling rates before leading to turbulence collapse. In the very stable moist cases, runaway cooling leads to substantial condensation of liquid water close to the ground and fog (visibility less than 1 km) results over much of the domain. In the weakly stable cases, turbulent mixing narrowly yields visibilities of 1 km close to the ground over a similar time period. Despite the idealised nature of the system, the present results suggest that turbulence impedes, although will not necessarily inhibit, fog formation. © 2020 22nd Australasian Fluid Mechanics Conference, AFMC 2020. All rights reserved.

关键词： Turbulence

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Author Correction: Interdecadal variability of terrestrial water storage since 2003

Communications Earth & Environment

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Communications Earth & Environment 2025年第1期6卷 1页

作者： Brett Buzzanga Ben Hamlington Felix Landerer Athina Peidou John Fasullo Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA Joint Institute for Regional Earth System Science and Engineering University of California Los Angeles Los Angeles California USA National Center for Atmospheric Research Boulder CO USA

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An Addendum to NeBula: Toward Extending Team CoSTAR’s Solution to Larger Scale Environments

IEEE Transactions on Field Robotics

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IEEE Transactions on Field Robotics 2024年 1卷 476-526页

作者： Benjamin Morrell Kyohei Otsu Ali Agha David D. Fan Sung-Kyun Kim Muhammad Fadhil Ginting Xianmei Lei Jeffrey Edlund Seyed Fakoorian Amanda Bouman Fernando Chavez Taeyeon Kim Gustavo J. Correa Maira Saboia Angel Santamaria-Navarro Brett Lopez Boseong Kim Chanyoung Jung Mamoru Sobue Oriana Claudia Peltzer Joshua Ott Robert Trybula Thomas Touma Marcel Kaufmann Tiago Stegun Vaquero Torkom Pailevanian Matteo Palieri Yun Chang Andrzej Reinke Matthew Anderson Frederik E. T. Schöller Patrick Spieler Lillian M. Clark Avak Archanian Kenny Chen Hovhannes Melikyan Anushri Dixit Harrison Delecki Daniel Pastor Barry Ridge Nicolas Marchal Jose Uribe Sharmita Dey Kamak Ebadi Kyle Coble Alexander Nikitas Dimopoulos Vivek Thangavelu Vivek S. Varadharajan Nicholas Palomo Antoni Rosinol Arghya Chatterjee Christoforos Kanellakis Bjorn Lindqvist Micah Corah Kyle Strickland Ryan Stonebraker Michael Milano Christopher E. Denniston Sami Sahnoune Thomas Claudet Seungwook Lee Gautam Salhotra Edward Terry Rithvik Musuku Robin Schmid Tony Tran Ara Kourchians Justin Schachter Hector Azpurua Levi Resende Arash Kalantari Jeremy Nash Josh Lee Christopher Patterson Jennifer G. Blank Kartik Patath Yuki Kubo Ryan Alimo Yasin Almalioglu Aaron Curtis Jacqueline Sly Tesla Wells Nhut T. Ho Mykel Kochenderfer Giovanni Beltrame George Nikolakopoulos David Shim Luca Carlone And Joel Burdick NASA Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA Department of Mechanical and Civil Engineering California Institute of Technology Pasadena CA USA Institut de Robòtica i Informàtica Industrial CSIC-UPC Barcelona Spain Department of Aerospace Engineering Korea Advanced Institute of Science and Technology Daejeon South Korea Department of Aeronautics and Astronautics Stanford University Stanford CA USA Department of Electrical And Information Engineering Polytechnic University of Bari Bari Italy Department of Aeronautics and Astronautics Massachusetts Institute of Technology Cambridge MA USA Department of Electrical and Computer Engineering Cornell University Ithaca NY USA Department of Computer Engineering and Software Engineering École Polytechnique de Montréal Montreal QC Canada Department of Computer Science Electrical and Space Engineering Luleå University of Technology Luleå Sweden Department of Mechanical Engineering California State University at Northridge Northridge CA USA Department of Earth and Planetary Sciences McGill University Montreal QC Canada Blue Marble Space Institute of Science Seattle WA USA

This article presents an appendix to the original NeBula autonomy solution developed by the Team Collaborative SubTerranean Autonomous Robots (CoSTAR), participating in the DARPA Subterranean Challenge. Specifically, this article presents extensions to NeBula’s hardware, software, and algorithmic components that focus on increasing the range and scale of the exploration environment. From the algorithmic perspective, we discuss the following extensions to the original NeBula framework: 1) large-scale geometric and semantic environment mapping; 2) an adaptive positioning system; 3) probabilistic traversability analysis and local planning; 4) large-scale partially observable Markov decision process (POMDP)-based global motion planning and exploration behavior; 5) large-scale networking and decentralized reasoning; 6) communicationaware mission planning; and 7) multimodal ground–aerial exploration *** demonstrate the application and deployment of the presented systems and solutions in various large-scale underground environments, including limestone mine exploration scenarios as well as deployment in the DARPA Subterranean challenge.

关键词： Planning State estimation Semantics NASA Hardware Three-dimensional displays systems architecture

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Deriving Velocity Fields of Submesoscale Eddies Using Multi-Sensor Imagery

Deriving Velocity Fields of Submesoscale Eddies Using Multi-...

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IEEE International Symposium on Geoscience and Remote Sensing (IGARSS)

作者： Igor Yanovsky Benjamin Holt Francois Ayoub Joint Institute for Regional Earth System Science and Engineering University of California Los Angeles CA USA Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA

ISBN: (数字)9781728163741

ISBN: (纸本)9781728163758

Small ocean eddies are observed in fine-resolution satellite imagery within the coastal regions and ice margins of the world's oceans. The derivation of surface velocity fields of these features would enable geophysical estimates of the kinematic energy contained within the eddies, leading to improved understanding of the role these eddies play in ocean circulation. In this paper, we develop a method to derive surface velocity fields of small ocean eddies using fine resolution, multi-sensor imagery obtained over short time intervals. We consider the evolving image to be embedded in a deformable medium, and perform image matching using nonlinear viscous fluid registration model. We employ sum of squared differences and mutual information as matching functionals. The physical continuum equation is solved using an efficient multigrid full approximation scheme. We test our method using synthetic aperture radar (SAR) image pairs and show that it produces promising results.

关键词： Sea surface Satellites Biomedical imaging Sea measurements Optical sensors Mathematical model Image registration

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Amazonian terrestrial water balance inferred from satellite-derived water vapor isotopes

Research Square

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Research Square 2021年

作者： Shi, Mingjie Worden, John R. Bailey, Adriana Noone, David Risi, Camille Fu, Rong Worden, Sarah Herman, Robert Payne, Vivienne Pagano, Thomas Bowman, Kevin Bloom, A. Anthony Saatchi, Sassan Liu, Junjie Fisher, Joshua B. Joint Institute for Regional Earth System Science and Engineering Department of Atmospheric and Oceanic Sciences University of California Los Angeles United States Pacific Northwest National Laboratory United States Jet propulsion Laboratory California Institute of Technology United States National Center for Atmospheric Research United States University of Auckland New Zealand Laboratoire de Météorologie Dynamique France University of California Los Angeles United States

The evolution of the Amazon forest is tightly coupled to its terrestrial water balance (evapotranspiration minus precipitation, or ET-P), as an increase in ET-P reduces soil moisture, increasing water stress. However, large differences of ~50% between current monthly estimates of ET-P make it challenging to confidently quantify its spatio-temporal distribution and evolution. Here, we show that new satellite observations of the HDO/H2O ratio of water vapor, spanning 2003 to 2020, constrain estimates of the Amazon water balance with monthly precision of ~20%. The HDO/H2O ratio of water vapor is sensitive to the difference between ET and P, rather than to either flux alone, because lighter isotopes preferentially evaporate and heavier isotopes preferentially condense. Consequently, variable bias and sensitivity errors that result from combining different ET and precipitation products are minimized with this proxy. Our analysis demonstrates these data can quantify the spatial patterns of Amazon water balance from monthly to interannual time scales. © 2021, CC BY.

关键词： Evapotranspiration

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Complications in the ALMA detection of phosphine at Venus

arXiv

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arXiv 2021年

作者： Akins, Alex B. Lincowski, Andrew P. Meadows, Victoria S. Steffes, Paul G. Jet Propulsion Laboratory California Institute of Technology Instruments Division PasadenaCA91011 United States Department of Astronomy and Astrobiology Program University of Washington Box 351580 SeattleWA98195 United States NASA Nexus for Exoplanet System Science Virtual Planetary Laboratory Team University of Washington Box 351580 SeattleWA98195 United States School of Electrical and Computer Engineering Georgia Institute of Technology AtlantaGA30308 United States

Recently published ALMA observations suggest the presence of 20 ppb PH3 in the upper clouds of Venus. This is an unexpected result, as PH3 does not have a readily apparent source and should be rapidly photochemically destroyed according to our current understanding of Venus atmospheric chemistry. While the reported PH3 spectral line at 266.94 GHz is nearly co-located with an SO2 spectral line, the non-detection of stronger SO2 lines in the wideband ALMA data is used to rule out SO2 as the origin of the feature. We present a reassessment of wideband and narrowband datasets derived from these ALMA observations. The ALMA observations are re-reduced following both the initial and revised calibration procedures discussed by the authors of the original study. We also investigate the phenomenon of apparent spectral line dilution over varying spatial scales resulting from the ALMA antenna configuration. A 266.94 GHz spectral feature is apparent in the narrowband data using the initial calibration procedures, but this same feature can not be identified following calibration revisions. The feature is also not reproduced in the wideband data. While the SO2 spectral line is not observed at 257.54 GHz in the ALMA wideband data, our dilution simulations suggest that SO2 abundances greater than the previously suggested 10 ppb limit would also not be detected by ALMA. Additional millimeter, sub-millimeter, and infrared observations of Venus should be undertaken to further investigate the possibility of PH3 in the Venus atmosphere. © 2021, CC BY-NC-SA.

关键词： Antennas

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Solar power system and radioisotope thermoelectric generation technologies at Jupiter-Saturn-Uranus environments: New insights and paradigms 70

Solar power system and radioisotope thermoelectric generatio...

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70th International Astronautical Congress, IAC 2019

作者： Hendricks, Terry J. Boca, Andreea Woerner, David F. Donitz, Benjamin Bairstow, Brian K. Power and Sensors System Section Project Systems Engineering Formulation Section NASA-Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Drive M.S. 277-207 PasadenaCA91109 United States

Power system selection for outer planet destinations, such as Jupiter, Saturn, and Uranus and beyond, is complex, involving and dependent on many interdisciplinary factors such as power system mass, specific power, cost, mechanical and electrical integration, and natural radiation environment. Low solar irradiance at Jupiter, Saturn, and Uranus systems (i.e., 50, 15, and 4 W/m2, respectively) makes solar power systems challenging in mechanical / electrical integration and accommodating radiation environments. More costly radioisotope thermoelectric generator (RTG) systems can help proposed missions overcome radiation environment and spacecraft control challenges at Jupiter, Saturn, and Uranus. NASA's jet propulsion laboratory (JPL) has recently made significant strides in demonstrating high-efficiency, radiation-hard solar cell technologies for low-irradiance, low-temperature (LILT) applications, and high-efficiency thermoelectric (TE) materials and modules for higher-specific-power RTGs. State-of-art multi-junction solar cells now routinely demonstrate high efficiencies of 30-34% at LILT (9.5AU and -165°C), making solar arrays a viable option for many near-term Saturn mission concepts. Emerging technologies like LILT-optimized solar cells have recently demonstrated even higher efficiencies of 37% at 9.5AU and -165°C and 30% lower mass than the state-of-art, offering the prospect of ~3W/kg array-level, end-of-life specific powers under Saturn conditions. Having already demonstrated the tremendous utility of RTGs on Mars and in deep-space missions (e.g., Galileo at Jupiter, New Horizons at Pluto), NASA is now developing and demonstrating new TE materials and modules (e.g., skutterudites, La3-x Te4, and Zintls) for increasing RTG specific power (up to >8.5 W/kg), which strongly impacts an RTG's mass, fuel utilization, and modularity in the power system trade domain. New accomplishments in both areas highlight the renewed requisite for updated comparisons and trade-off

关键词： NASA

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CIBER 4th flight fluctuation analysis: Measurements of near-IR auto- and cross-power spectra on arcminute to sub-degree scales

arXiv

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arXiv 2025年

作者： Feder, Richard M. Bock, James J. Cheng, Yun-Ting Cooray, Asantha Korngut, Phillip M. Matsuura, Shuji Mirocha, Jordan Nguyen, Chi H. Takimoto, Kohji Tsumura, Kohji Wills, Ryan Zemcov, Michael California Institute of Technology 1200 E California Blvd 91125 United States Berkeley Center for Cosmological Physics University of California BerkeleyCA94720 United States Lawrence Berkeley National Laboratory BerkeleyCA94720 United States Department of Physics & Astronomy University of California Irvine IrvineCA92697 United States School of Science and Technology Kwansei Gakuin University Hyogo Sanda669-1337 Japan Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Drive PasadenaCA91109 United States Department of Solar System Sciences Institute of Space and Astronautical Science Japan Aerospace Exploration Agency 3-1-1 Yoshinodai Chuo-ku Kanagawa Sagamihara252-5210 Japan Department of Natural Sciences Faculty of Science and Engineering Tokyo City University Tokyo158-8557 Japan Center for Detectors School of Physics and Astronomy Rochester Institute of Technology 1 Lomb Memorial Drive RochesterNY14623 United States

We present new anisotropy measurements in the near-infrared (NIR) for angular multipoles 300 5 using imaging data at 1.1 µm and 1.8 µm from the fourth flight of the Cosmic Infrared Background ExpeRiment (CIBER). Using improved analysis methods and higher quality fourth flight data, we detect surface brightness fluctuations on scales 5′, the CIBER auto- and cross-power spectra exceed predictions for integrated galactic light (IGL) and integrated stellar light (ISL) by over an order of magnitude, and are inconsistent with our baseline IGL+ISL+DGL model at high significance. We cross-correlate two of the CIBER fields with 3.6 µm and 4.5 µm mosaics from the Spitzer Deep Wide-Field Survey and find similar evidence for departures from Poisson noise in Spitzer-internal power spectra and CIBER × Spitzer cross-power spectra. A multi-wavelength analysis indicates that the auto-power of the fluctuations at low- is bluer than the Poisson noise from IGL and ISL;however, for 1′ ′, the cross-correlation coefficient r of nearly all band combinations decreases with increasing θ, disfavoring astrophysical explanations that invoke a single correlated sky component. © 2025, CC BY.

关键词： Infrared devices

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