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OCEANS 2024 - Halifax, OCEANS 2024

作者： Srinivasan, Margaret Tsontos, Vardis California Institute of Technology Applied Science System Engineering Jet Propulsion Laboratory PasadenaCA United States

ISBN: (纸本)9798331540081

A continuous global satellite radar altimetry data time series spanning 32 years has made significant advances in research and operational applications possible. The TOPEX/Poseidon satellite mission, launched in 1992, was intended to test technology and data systems to precisely measure height variations across the ocean-'ocean surface topography' (OST) -on a global scale from space. The mission performed so successfully that it was followed by the 'Jason-series' satellites;Jason 1, Jason 2, Jason 3, and the newest, Sentinel 6 Michael Freilich, with more satellites in the series in preparation. These U.S.-European collaborations have significantly enhanced understanding of ocean and coastal dynamics and have made large-scale reservoir and lake observations since 1992. The 2022 launch of the Surface Water and Ocean Topography (SWOT) mission has further advanced knowledge of ocean dynamics and extends observations to high-resolution land surface water observations. OST data have been crucial in monitoring global sea level rise, understanding ocean circulation and heat content, and supporting coastal impact assessments and climate modeling. Beyond research, OST observations benefit operational oceanographic and water resource organizations and weather forecasting agencies worldwide. They inform shipping, fishery and marine operations, and decision-making and disaster management in coastal zones. The continuous OST record aids in analyzing trends, tracking sea-level rise, assessing ocean health, and supporting climate change mitigation strategies. Partnerships between NASA, the French space agency, Centre National d'Etudes Spatiales (CNES), NOAA, the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) Space Agency (ESA), and the European meteorological and EUMETSAT have been instrumental in developing an essential climate data record, providing substantial value to both research and operational communities. This talk, summarizing findings

关键词： NASA

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Current Status and Analyses of the SPLICE Hazard Detection software

Current Status and Analyses of the SPLICE Hazard Detection S...

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AIAA Science and Technology Forum and Exposition, AIAA SciTech Forum 2025

作者： Liu, John Y. Chen, Po-Ting Aldrich, Jack D. Bocchino, Robert L. Vaughan, Geoffrey Jet Propulsion Laboratory California Institute of Technology Payload/Instrument Pointing Control Systems Engineering Guidance and Control Section 4800 Oak Grove Drive PasadenaCA91109 United States Jet Propulsion Laboratory California Institute of Technology Guidance and Control Section 4800 Oak Grove Drive PasadenaCA91109 United States Jet Propulsion Laboratory California Institute of Technology Flight Software and Avionics Systems Section 4800 Oak Grove Drive PasadenaCA91109 United States

This paper provides a status report of the current development and analysis efforts for the hazard detection (HD) software for the Safe and Precise Landing-Integrated Capabilities Evolution (SPLICE) project. © 20... 详细信息

ISBN: (数字)9781624107238

ISBN: (纸本)9781624107238

关键词： Hazards

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Satellite Altimetry for Ocean and Coastal Applications: Promoting and Supporting Applications User Communities

Satellite Altimetry for Ocean and Coastal Applications: Prom...

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OCEANS

作者： Margaret Srinivasan Vardis Tsontos Applied Science System Engineering Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA

ISBN: (数字)9798331540081

ISBN: (纸本)9798331540098

A continuous global satellite radar altimetry data time series spanning 32 years has made significant advances in research and operational applications possible. The TOPEX/Poseidon satellite mission, launched in 1992, was intended to test technology and data systems to precisely measure height variations across the ocean-“ocean surface topography” (OST) -on a global scale from space. The mission performed so successfully that it was followed by the “Jason-series” satellites; Jason 1, Jason 2, Jason 3, and the newest, Sentinel 6 Michael Freilich, with more satellites in the series in preparation. These U.S.-European collaborations have significantly enhanced understanding of ocean and coastal dynamics and have made large-scale reservoir and lake observations since 1992. The 2022 launch of the Surface Water and Ocean Topography (SWOT) mission has further advanced knowledge of ocean dynamics and extends observations to high-resolution land surface water observations. OST data have been crucial in monitoring global sea level rise, understanding ocean circulation and heat content, and supporting coastal impact assessments and climate modeling. Beyond research, OST observations benefit operational oceanographic and water resource organizations and weather forecasting agencies worldwide. They inform shipping, fishery and marine operations, and decision-making and disaster management in coastal zones. The continuous OST record aids in analyzing trends, tracking sea-level rise, assessing ocean health, and supporting climate change mitigation strategies. Partnerships between NASA, the French space agency, Centre National d'Etudes Spatiales (CNES), NOAA, the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) Space Agency (ESA), and the European meteorological and EUMETSAT have been instrumental in developing an essential climate data record, providing substantial value to both research and operational communities. This talk, summarizing findings

关键词： Sea surface Satellites Time series analysis Sea measurements Land surface Europe Weather forecasting Aerospace electronics Surface topography Altimetry

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Middlebox Detection: Evasion and Effectiveness

Middlebox Detection: Evasion and Effectiveness

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International Black Sea Conference on Communications and Networking (BlackSeaCom)

作者： Vahab Pournaghshband Hassan Pournaghshband Eric Vance Computer Science Department University of San Francisco San Francisco USA Software Engineering Department Kennesaw State University Atlanta USA Jet Propulsion Laboratory NASA Pasadena USA

ISBN: (数字)9798350351859

ISBN: (纸本)9798350351866

Network middleboxes are crucial for the security and efficiency of modern Internet infrastructure, performing various tasks that necessitate robust detection and localization tools. Traditional detection strategies often overlook the adaptability of these middleboxes, which can actively avoid detection. To address this, our paper examines how adversaries can manipulate network traffic to undermine detection tools, focusing on strict priority queueing (SPQ) as an example. We introduce an adversary model that uses SPQ to mask discriminatory traffic handling from detection tools. Simulations show that under specific conditions, a middlebox can successfully evade detection by standard SPQ detection tools.

关键词： Location awareness Adaptation models Focusing Telecommunication traffic Middleboxes Security Task analysis

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Deep Self-Supervised Disturbance Mapping with the OPERA Sentinel-1 Radiometric Terrain Corrected SAR Backscatter Product

arXiv

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arXiv 2025年

作者： Hardiman-Mostow, Harris Marshak, Charles Handwerger, Alexander L. Department of Mathematics University of California - Los Angeles Los AngelesCA90095 United States Jet Propulsion Laboratory California Institute of Technology PasadenaCA91109 United States Jet Propulsion Laboratory California Institute of Technology United States Joint Institute for Regional Earth System Science and Engineering University of California Los Angeles United States

Mapping land surface disturbances supports disaster response, resource and ecosystem management, and climate adaptation efforts. Synthetic aperture radar (SAR) is an invaluable tool for disturbance mapping, providing consistent timeseries images of the ground regardless of weather or illumination conditions. Despite SAR’s potential for disturbance mapping, processing SAR data to an analysis-ready format requires expertise and significant compute resources, particularly for large-scale global analysis. In October 2023, NASA’s Observational Products for End-Users from Remote Sensing Analysis (OPERA) project released the near-global Radiometric Terrain Corrected SAR backscatter from Sentinel-1 (RTC-S1) dataset, providing publicly available, analysis-ready SAR imagery. In this work, we utilize this new dataset to systematically analyze land surface disturbances. As labeling SAR data is often prohibitively time-consuming, we train a self-supervised vision transformer - which requires no labels to train - on OPERA RTC-S1 data to estimate a per-pixel distribution from the set of baseline imagery and assess disturbances when there is significant deviation from the modeled distribution. To test our model’s capability and generality, we evaluate three different natural disasters - which represent high-intensity, abrupt disturbances - from three different regions of the world. Across events, our approach yields high quality delineations: F1 scores exceeding 0.6 and Areas Under the Precision-Recall Curve exceeding 0.65, consistently outperforming existing SAR disturbance methods. Our findings suggest that a self-supervised vision transformer is well-suited for global disturbance mapping and can be a valuable tool for operational, near-global disturbance monitoring, particularly when labeled data does not exist. Copyright © 2025, The Authors. All rights reserved.

关键词： Labeled data

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Sea level rise from melting glaciers and ice sheets caused by climate warming above pre-industrial levels

Sea level rise from melting glaciers and ice sheets caused b...

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作者： Rignot, E. University of California Irvine Dept. Earth System Science IrvineCA92697 United States Jet Propulsion Laboratory/Caltech PasadenaCA91109 United States University of California Irvine Dept. Civil and Environmental Engineering IrvineCA92697 United States

The ice sheets in Greenland and Antarctica, combined with glaciers and ice caps around the world, are contributing faster and sooner than expected to global sea level rise. Half a century of observations, physical models, and paleoclimate records suggest that sea level rise will exceed 1 meter this century, but more extreme rates of sea level rise can not be ruled out. I review the current state of knowledge on ice sheet and glacier mass balance, its driving physical mechanisms, their impacts on future sea level rise, and whether the most vulnerable sectors of Antarctica and Greenland have passed, or will soon pass, a point of no return. In several sectors of Greenland and Antarctica, I conclude that multi-meter sea level rise is inevitable, but the rate of sea level rise will depend on how urgently we keep climate warming under control and subsequently bring the climate system back toward pre-industrial levels. To reduce the uncertainties of projecting rapid rates of sea level rise in the coming century, significant research investments will be required, orders of magnitude lower than the cost of adapting to sea level rise, to obtain critical observations and develop more reliable atmosphere-ocean-ice coupled models. © 2022 Uspekhi Fizicheskikh Nauk. All rights reserved.

关键词： Climate change

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The Pitfalls of Ignoring Topography in Snow Retrievals: A Case Study with Emit

SSRN

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SSRN 2024年

作者： Bohn, Niklas Bair, Edward H. Brodrick, Philip G. Carmon, Nimrod Green, Robert O. Painter, Thomas H. Thompson, David R. Jet Propulsion Laboratory California Institute of Technology PasadenaCA United States Civil Group Leidos Inc. RestonVA United States Joint Institute for Regional Earth System Science and Engineering UCLA Los AngelesCA United States

Snow and ice surfaces are an important modulator of Earth’s climate as they reflect most of the incoming solar radiation favoring substantial cooling effects. Thereby, the amount of absorbed solar illumination regulates radiative forcing, which in turn steers melting processes on ice sheets and glaciers. Global patterns of snow darkening, induced by the accumulation of small light-absorbing particles (LAPs), such as dust or algae, lead to an intensified radiative forcing and melting of Earth’s snow cover. It is one of the driving factors for both global sea level rise and increasing air temperature. Mapping and quantifying LAPs on both temporal and spatial scales is therefore needed to improve the prediction of melt rates and their impacts on climate change. High-resolution visible-to-shortwave-infrared (VSWIR) imaging spectrometers herald a new era of passive spaceborne remote sensing, which will help to fulfill this objective. This technology provides continuous spectral channels throughout the solar spectrum, allowing to detect narrow LAP absorption bands. One of these instruments is NASA’s Earth Surface Mineral Dust Source Investigation (EMIT) that was launched to the International Space Station (ISS) in July 2022. The prime mission focus is to deliver maps of surface minerals from arid dust source regions in order to inform Earth system models (ESM) of atmospheric transport and radiative forcing. In addition, the EMIT target mask also includes snow cover in low to mid-latitude mountainous regions, such as the Western US, the Andes in South America, or high-mountain Asia, all of which are prone to surface deposition of small dust particles after traveling hundreds to thousands of kilometers through the atmosphere. Accurate retrievals of snow surface properties in those regions require precise accounting for anisotropy and topography due to varying forward scattering intensity as a function of illumination and observation geometry. In this contribution, we invert

关键词： Radiative transfer

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EFFICIENT STARSHADE RETARGETING ARCHITECTURE USING CHEMICAL propulsion

EFFICIENT STARSHADE RETARGETING ARCHITECTURE USING CHEMICAL ...

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AAS/AIAA Astrodynamics Specialist Conference, 2020

作者： Flinois, Thibault L. B. Seubert, Carl R. Scharf, Daniel P. Lisman, P. Douglas Payload/Instrument Pointing Control Analysis Group Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Dr. PasadenaCA91109 United States Spacecraft Guidance & Control Analysis Group Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Dr. PasadenaCA91109 United States Instrument System Engineering Group Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Dr. PasadenaCA91109 United States

ISBN: (纸本)9780877036753

NASA is studying a possible starshade flying in formation with the Nancy Grace Roman Space Telescope (Roman). The starshade would perform weeks-long translational retargeting maneuvers between target stars. A retargeting architecture is introduced that is based on chemical propulsion and does not require ground tracking or interactions with the telescope during the retargeting cruise. Feasibility is demonstrated through a verified covariance analysis of the starshade-telescope relative position over several weeks using realistic sensor and actuator assumptions. Performance is sufficient for Roman to reacquire the starshade after retargeting and the architecture is shown to also be applicable to other mission concepts such as the Habitable Exoplanet Observatory (HabEx). © 2021, Univelt Inc. All rights reserved.

关键词： Architecture

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Estimating Dust on Snow - Application of a Coupled Atmosphere-Surface Model to Spaceborne Emit Imaging Spectrometer Data

Estimating Dust on Snow - Application of a Coupled Atmospher...

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IEEE International Symposium on Geoscience and Remote Sensing (IGARSS)

作者： N. Bohn E. H. Bair P. G. Brodrick N. Carmon R. O. Green T. H. Painter D. R. Thompson Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA Earth Research Institute University of California Santa Barbara CA USA Joint Institute for Regional Earth System Science and Engineering University of California Los Angeles CA USA

Radiative forcing by small dust particles deposited on snow plays a key role in climate change. Detection and quantification of these particles is essential for predicting melt rates, and assessing the associated impacts on Earth’s climate. NASA’s Earth Surface Mineral Dust Source Investigation (EMIT) aims to improve our understanding of the Earth’s dust source and sink regions. The latter include snow surfaces in topographically challenging mountainous terrain. We present estimated snow reflectance, dust concentration, and radiative forcing from a new retrieval framework, and highlight their sensitivity to topographic characteristics. These findings will be essential for updating snow melt and climate models, but also for the conception of retrieval algorithms for upcoming global spaceborne imaging spectroscopy missions, including NASA’s Surface Biology and Geology (SBG).

关键词：

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PID Parameter Optimization of Secondary Cooling Water Distribution Model for Continuous Casting Based on Improved Artificial Bee Colony Algorithm 4

PID Parameter Optimization of Secondary Cooling Water Distri...

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4th International Conference on Artificial Intelligence and Big Data, ICAIBD 2021

作者： Wang, Yibing Kong, Xiangwei Hao, Peifeng Software College Northeastern University Shenyang China School of Mechanical Engineering Automation Liaoning Province Key Laboratory of Multidisciplinary Design Optimization of Complex Equipment Northeastern University Key Laboratory of Vibration and Control of Aero-Propulsion System Ministry of Education Shenyang China

ISBN: (纸本)9780738131702

Dynamic control of secondary cooling in continuous casting is the key technology to improve the quality and efficiency of the slab. In order to improve the quality and efficiency of the slab, a new control strategy of secondary cooling water distribution based on an improved artificial bee colony algorithm is proposed. Based on the traditional artificial bee colony algorithm, adding the learning factor to the optimal individual learning factor and random individual of the current population and integrating the output overshoot mechanism into the objective function is effective to avoid the great overshoot phenomenon caused by the abruptly change of casting speed and the large fluctuation of casting surface temperature. The transfer function was constructed based on the coupling relationship between the distribution of secondary cooling water and slab surface temperature. The Simulink simulation model was established, which was compared with the PSO-DSWPI Method and conventional PID controller. The results showed that the improved artificial bee colony algorithm has a more minor error, higher control accuracy and more smooth step response, which provided a new method for realizing more accurate control of secondary cooling dynamic water distribution and had practical significance for improving slab quality. © 2021 IEEE.

关键词： Cooling water

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