cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.48577/jpl.5j5olv
title: CATEGORIZING MODELS USING SELF-ORGANIZING MAPS: AN APPLICATION TO MODIFIED GRAVITY THEORIES PROBED BY COSMIC SHEAR

description: We propose to use Self-Organizing Maps (SOM) to map the impact of physical models onto observables. Using this approach, we are be able to determine how theories relate to each other given their signatures. In cosmology this will be particularly useful to determine cosmological models (such as dark energy, modified gravity or inflationary models) that should be tested by the new generation of experiments. As a first example, we apply this approach to the representation of a subset of the space of modified gravity theories probed by cosmic shear. We therefore train a SOM on shear correlation functions in the f(R), dilaton and symmetron models. The results indicate these three theories have similar signatures on shear for small values of their parameters but the dilaton has different signature for higher values. We also show that modified gravity (especially the dilaton model) has a different impact on cosmic shear compared to a dynamical dark energy so both need to be tested by galaxy surveys.
DOI: 10.48577/jpl.najt03
title: Submersible Capillary Electrophoresis Analyzer: A Proof-of-Concept Demonstration of an In Situ Instrument for Future Mis-sions to Ocean Worlds

description: We report here the first fully automated capillary electrophoresis system (CE) that can be operated underwater. The system per-forms sample acquisition and analysis by coupling CE to contactless conductivity detection. Using 5 M acetic acid as the back-ground electrolyte (BGE), inorganic cations and amino acids at concentrations as low as 5.2 µM can be separated and identified. This technology could be augmented to include a variety of other detection modes. Fleets of such systems could be deployed ro-botically to generate chemical and biological gradients over regional to global scales, enabling ecosystem level studies at an un-precedented level of molecular detail. Additionally, this system serves as an early prototype for potential future underwater ex-plorers on ocean worlds of the outer solar system such as Europa or Enceladus. This work documents the first step in the devel-opment of this general-purpose technology platform.
DOI: 10.48577/jpl.mwxu1d
title: Precision of Spacecraft Doppler Tracking at Low Signal-to-Noise Ratios

description: The signal-to-noise ratio received at Earth is typically larger than 10 dB-Hz for radio tracking of a spacecraft in deep space, allowing a phase-locked loop to execute reliable carrier tracking. Recently, missions have been proposed to utilize low-gain antennas for Doppler tracking where the signal-to-noise ratio may be at the single-digit (dB-Hz) level. In this work, we discuss spacecraft Doppler tracking at these low signal-to-noise ratios through an analysis of thermal noise on the radio link, results from ground testing with the Deep Space Network, and demonstrations with an active spacecraft. We show that by utilizing an open-loop receiver to capture the carrier signal and by applying post-processing techniques, radio data with the signal-to-noise ratio as low as 4 dB-Hz can be used to derive Doppler data with precision sufficient for tracking a spacecraft in deep space.
DOI: 10.48577/jpl.76iqn2
title: An investigation on the damping ratio of marine oil slicks in synthetic aperture radar imagery

description: The damping ratio has recently been used to indicate the relative internal oil thickness within oil slicks observed in synthetic aperture radar (SAR) imagery. However, there exists no well-defined and evaluated methodology for calculating the damping ratio. In this study, we review prior work regarding the damping ratio and outline its theoretical and practical aspects. We show that the most often used methodology yields damping ratio values that differ, in some cases significantly, for the same scene. Three alternative methods are tested on multifrequency data sets of verified oil slicks acquired from DLR’s F-SAR instrument, NASA’s Unmanned Aerial Vehicle Synthetic Aperture Radar (UAVSAR) and Sentinel- 1. All methods yielded similar results regarding relative thickness variations within slick. The proposed damping ratio derivation methods were found to be sensitive to the proportion of oil covered pixels versus open water pixels in the azimuth direction, as well as to the scene size in question. We show that the fully automatable histogram method provides the most consistent results even under challenging conditions. Comparisons between optical imagery and derived damping ratio values using F-SAR data show good agreement between the relatively thicker oil slick areas for the two different types of sensors.
DOI: 10.48577/jpl.dfeue3
title: ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP): A forming quadruple system with continuum ‘ribbons’ and intricate outflows

description: One of the most poorly understood aspects of low-mass star formation is how multiple-star systems are formed. Here we present the results of Atacama Large Millimeter/submillimeter Array (ALMA) Band-6 observations towards a forming quadruple protostellar system, G206.93-16.61E2, in the Orion B molecular cloud. ALMA 1.3mm continuum emission reveals four compact objects, of which two are Class I young stellar objects (YSOs), and the other two are likely in prestellar phase. The 1.3 mm continuum emission also shows three asymmetric ribbon-like structures that are connected to the four objects, with lengths ranging from ∼500 au to ∼2200 au. By comparing our data with magnetohydrodynamic (MHD) simulations, we suggest that these ribbons trace accretion flows and also function as gas bridges connecting the member protostars. Additionally, ALMA CO J =2-1 line emission reveals a complicated molecular outflow associated with G206.93-16.61E2 with arc-like structures suggestive of an outflow cavity viewed pole-on.
DOI: 10.48577/jpl.o2jqry
title: Imaging rotating and orbiting exoplanets with the solar gravitational lens

description: We utilize the well-established properties of the solar gravitational lens (SGL) to consider realistic observational scenarios. Actual exoplanets, which may be the target of an SGL observational campaign, are not stationary. Their appearance changes as a result of their diurnal rotation and varying illumination due to their orbital motion around their host star. The nature of the SGL is such that imaging with one telescope is accomplished with a cadence of one pixel at a time, with substantial per-pixel integration times. Therefore, capturing a single snapshot of the target planet with a realistically-sized telescope is not possible. Instead, the planetary surface must be reconstructed by inverting the combined effect of the SGL's point-spread function and temporal changes induced by the planetary dynamics. Using the Earth as a stand-in, we demonstrate practical feasibility of this approach, by simulating a dynamical system and then recovering topographic images of acceptable quality. The dynamics-induced temporal variability of the exoplanet represents an added challenge, but even in the presence of such dynamics, use of the SGL for exoplanet imaging remains feasible.
DOI: 10.48577/jpl.qfgpuf
title: The Effect of Time-Varying Currents on Hollow Cathode Operation

description: A novel fast-scanning fiber optic probe, high speed swept Langmuir probe and fast ion saturation probe were used to measure the emitter temperature and internal plasma properties in a hollow cathode over a range of magnetic fields, flow rates, and DC currents. Additional measurements were performed using AC currents injected in parallel with the nominal DC current to determine how the hollow cathode accommodates demands for time-varying currents in a Hall thruster. Demands for higher steady state discharge current levels are accommodated primarily by an increase in cathode temperature. The plasma density increases by up to 70% as the current rises from 14.2 to 30.2 A, and the plasma becomes more concentrated at the downstream end. The electron temperature shows no significant changes over this range of currents. The plasma potential is negatively correlated with the discharge current, dropping by 2 - 3 V as the current is increased from 14.2 A to 30.2 A. The mechanism in this case is likely changes in thermionic emission due to temperature changes, with the sheath voltage playing a role in fine-tuning the net current. With kHz-frequency current oscillations, there is no evidence that the cathode temperature adjusts to accommodate the rapid changes. The key difference between changes in DC current level and rapid changes with oscillating currents is in the behavior of the plasma potential. In contrast to the drop in plasma potential observed with increasing DC currents, the potential increases as current increases over a cycle with time-varying currents. This suggests that the mechanism for accommodating time-varying currents is an adjustment in the cathode sheath, modulating the return electron current, which is reflected in the centerline plasma potential variations.
DOI: 10.48577/jpl.v6iilv
title: Status Update on the NEO Surveyor Detector Development

description: NEO Surveyor is a NASA Planetary Defense Coordination Office mission designed to detect and track &gt;2/3 of potentially hazardous asteroids &gt;140 m in diameter during its 5-year prime mission. NEO Surveyor entered Phase B in June 2021 and is scheduled to launch in 2026 to survey the sky in two infrared bands. The infrared detectors are a key technology for the mission and have been the subject of focused development for more than a decade. In this paper, we report test results for recently produced detectors and describe design elements of the focal plane module relevant to operations for NEO Surveyor.
DOI: 10.48577/jpl.1rubfp
title: NASA's Starshade Technology Development Activity

description: The Astro2020 report recommended that NASA’s next flagship have direct imaging of rocky, Earthlike exoplanets as its core science mission. At present, the starshade is the only high contrast imaging technique that has demonstrated broadband contrast at levels suitable for imaging exo-Earths in the laboratory. A starshade is an occulter positioned to cast a shadow of an exoplanet’s host star onto the telescope aperture, and narrow enough that the nearby exoplanet remains visible to the telescope. The starshade has a precise shape tailored to suppress diffraction of the starlight into the shadow. Starshade-based observations also have other advantages compared to coronagraphic observations. These include: no effective limit to the outer working angle, higher throughput for the exoplanet light, dramatically simpler requirements on the telescope optics, and the ability to provide high contrast at ultraviolet wavelengths. These advantages come at the price of needing a separate spacecraft to fly the starshade in formation with the telescope, and the consequent costs in fuel and time required for stationkeeping and retargeting. We describe work being done to mature starshade technology to technology readiness level 5 (TRL 5) in NASA’s S5 activity. This work includes optical measurements of a starshade’s ability to suppress light at levels required for a flagship mission, laboratory demonstrations of position sensing and control methods for starshade formation flying, and manufacture and test of flight-like starshade mechanical assemblies that can deploy accurately and stably to the precise shape required for starlight suppression in space.
DOI: 10.48577/jpl.kf8egr
title: Systems Integration and Test of the Lunar Flashlight Spacecraft

description: Lunar Flashlight is a 6U CubeSat launching in late 2022 or early 2023 that will search for surface water ice content in permanently shadowed regions at the south pole of the Moon using infrared relative reflectance spectroscopy. The mission will act as a technology demonstration of an Advanced Spacecraft Energetic NonToxic (ASCENT) green propulsion system and active laser spectroscopy within the CubeSat form-factor. This paper provides an overview of the entire Systems Integration and Test campaign which took place at the Jet Propulsion Laboratory and the Georgia Institute of Technology. From initial testing of the isolated avionics and payload subsystems to the final tests with a fully integrated spacecraft, the functional and environmental test campaign is reviewed, with a focus on lessons learned.
DOI: 10.48577/jpl.87pz1y
title: Square Wave Test for Characterization of Compressor Piston Blowby

description: Modern cryocooler linear compressors commonly use clearance seals as the primary sealing mechanism between the piston and cylinder. Such clearance seals are just very narrow non-contacting radial gaps on the order of 5 to 10 microns (0.0002"-0.0004") that limit the gas flow past the piston to a tolerable level. Such clearances are quite demanding to produce and are extremely difficult to measure accurately, even when the piece parts are available before final assembly. One means of testing the gaps is via a blowby test –conducted prior to compressor completion–where the flowrate of gas through the assembled clearance seal is measured as a function of differential pressure applied across the piston. For narrow clearance-seal type gaps, the gas flowrate is proportional to the cube of the gap radial distance, so the blowby test can be a sensitive measure of the initial clearance seal dimensions in a compressor. Because piston blowby is often an important factor in cryocooler efficiency, and increased blowby can be an important indicator of possible life limiting piston/cylinder wear, having an independent means of accessing blowby in an operational cooler is very desirable. Unfortunately, once a compressor is assembled and sealed into a working cooler, the direct measurement of piston blowby is no longer possible. However, indirect means of qualitatively assessing blowby are possible. One means is the square wave test described in this paper. This test involves driving the compressor pistons with a low-frequency squarewave voltage while simultaneously measuring the piston stroke response over time.
DOI: 10.48577/jpl.n8p0yo
title: AIRS Pulse Tube Coolers Performance Update – 20 Years in Space

description: The Atmospheric Infrared Sounder (AIRS) instrument began operation 39 days after its May 4, 2002 launch into Earth orbit. It has now completed over twenty years of successful operation using a pair of Northrop Grumman pulse tube cryocoolers to cool its IR detectors. Designed with redundant cryocoolers (a primary and a backup), the instrument began operation using a single cooler to bear the load of both the detector and the nonoperating, backup cooler. However, 6 months after launch, a change in operating strategy was made to run both coolers simultaneously. This change led to the successful continuous 24/7 operation of both coolers over the past 19½ years. After a brief review of the AIRS instrument cryogenic design, detailed data are presented on the highly successful continuous operation of the AIRS pulse tube cryocoolers and instrument thermal design. A valuable feature has been the extremely stable temperatures provided to the instrument over its lifetime. This high level of operational stability not only indicates that the cryocoolers and thermal design have maintained near-constant efficiency, but the stability has also provided enormous benefits to the science data in terms of tracking long-term global changes. During its 20-year lifetime, the instrument itself has evolved in its mission scope and expanded its data gathering well beyond its original role as just a temperature sounder measuring global daily air temperature. It now generates a wealth of data not only on global air temperatures, but also on global and local greenhouse gas distributions. For example, AIRS can detect carbon monoxide emissions from large forest fires and can follow their giant plumes as the gas moves across the planet. At this time the cryocoolers continue in 24/7 operation and the AIRS instrument continues to generate daily scientific data on Earth’s atmospheric parameters.
DOI: 10.48577/jpl.lxvcen
title: Conceptual Design and Development History of the MIRI Cryocooler System on JWST

description: The Mid Infrared Instrument (MIRI) of the James Webb Space Telescope (JWST) is a demanding application for the use of space cryocoolers. Used to cool JWST’s ~100 kg MIRI instrument down to 6 K, the MIRI Cryocooler is critical to enabling the mission’s long-wave infrared science associated with studying the post-Big Bang early formation of the Universe. The selection and design of MIRI and its cryocooler system started with the successes and limitations of JWST’s precursor, the Hubble Space telescope. Planned as the follow-on to Hubble, JWST abandoned Hubble’s astronaut-accessible low-Earth orbit for a colder and better-science environment a million miles from Earth. Targeting for this L2 location meant no servicing missions would be possible, and reliability and life would be critically important. JWST’s increased size, with a 6.5 meter diameter mirror, meant significant deployments would be required post launch to allow the observatory to unfurl from its launch-vehicle shroud and separate the cold telescope from its hot and noisy spacecraft bus. The MIRI cryocooler system met these mission constraints by positioning its dual compressors inside the spacecraft bus, while the MIRI instrument and the cryocooler’s cold-end is positioned 10 meters away in the Science Instrument Module. Accommodating the 1.3-m deployment of the telescope away from the spacecraft and minimizing any vibration transmitted up the connecting refrigerant lines was a driving requirement on the cryocooler system. Providing MIRI’s large refrigeration load at 6 K, while simultaneously cooling MIRI’s 18 K radiation shield required an allnew hybrid Pulse Tube/Joule-Thomson cryocooler. This paper provides an overview of the overall MIRI cryocooler system as it evolved to meet these demanding JWST requirements over its nearly 20-year development history. During this period it drew heavily upon ongoing Pulse Tube cooler developments as well as a history of earlier hybrid J–T cryocooler technologies.
DOI: 10.48577/jpl.veg7au
title: NASA report to the GHRSST Science Team

description: No abstract available.
DOI: 10.48577/jpl.nojtg5
title: Low Cost Missions for Mars Exploration

description: No abstract available.
DOI: 10.48577/jpl.aso3mu
title: Modeling Molecular Outgassing Transport and Deposition for Spacecraft Operating in Vacuum

description: No abstract available.
DOI: 10.48577/jpl.gwg9jt
title: Evaluation of the COWVR+TEMPEST Channel Set for Estimating Precipitation Structure over a Variety of Surface Conditions

description: No abstract available.
DOI: 10.48577/jpl.fwmr6g
title: FT-IR measurements of cross sections for trans-2-Butene in the 7-15 µm region at 180-297 K for Titan’s atmosphere

description: No abstract available.
DOI: 10.48577/jpl.ejkksa
title: PDS Search API

description: No abstract available.
DOI: 10.48577/jpl.azqirp
title: Magma storage and transport along volcanic rift zones

description: No abstract available.
DOI: 10.48577/jpl.fj6qxy
title: Sensitivity of exo-Earth yield of a 6 m IR/O/UV telescope to bandwidth, SNR, and spectral resolution

description: No abstract available.
DOI: 10.48577/jpl.ttkklp
title: The shaping of Earth's climate through the cycles of water and energy

description: No abstract available.
DOI: 10.48577/jpl.pzwrc9
title: CO2 COLLISIONAL BROADENING OF THE 557 GHz WATER ABSORPTION FEATURE PROFILED WITH A DIF- FERENTIAL ABSORPTION RADAR PLATFORM

description: No abstract available.
DOI: 10.48577/jpl.5nkya4
title: Science and applications for the ASI-JPL collaboration

description: No abstract available.
DOI: 10.48577/jpl.zezcaw
title: FULL CALIBRATION OF THE SMAP-R DATASET

description: No abstract available.
DOI: 10.48577/jpl.oc8n0t
title: INITIAL EVALUATION OF SMAP R POLARIMETRY OVER LAND

description: No abstract available.
DOI: 10.48577/jpl.i4uarl
title: Disentangling drivers of regional trends in terrestrial water storage

description: No abstract available.
DOI: 10.48577/jpl.zrplg7
title: Mars 2020 System Thermal Vacuum (STV) Test Implementation and Results

description: No abstract available.
DOI: 10.48577/jpl.nx0buk
title: Humanlike Robots as Artificial Inspectors: The Science Fiction and Engineering Reality

description: No abstract available.
DOI: 10.48577/jpl.2oznzi
title: Advances in imaging spectrometer atmospheric correction with the open source ISOFIT codebase

description: No abstract available.
DOI: 10.48577/jpl.xz2npe
title: Radically Advancing the Capabilities of Space-based Computing

description: No abstract available.
DOI: 10.48577/jpl.cacnx2
title: Spatially Constrained Imaging Spectroscopy Retrievals

description: No abstract available.
DOI: 10.25952/41zk-dh20
title: An Exploration of Effective Pedagogical Practices for Mathematics Learning in the Nigerian Context - Dataset

description: The data compared and explored two pedagogical approaches related to the van Hiele theory and the cognitive load theory. Specifically, it compared the van Hiele teaching phases and the worked examples instruction for mathematics learning respectively. The study focuses on learning simultaneous equations and particularly on the acquisition and retention of knowledge, the conceptual and procedural knowledge acquired and retained and other students' characteristics such as gender. The data were obtained from senior secondary school students attending public co-education schools in Nigeria. This dataset consists of six different files which are obtained from two groups at three different time points.
description: The data compared and explored two pedagogical approaches related to the van Hiele theory and the cognitive load theory. Specifically, it compared the van Hiele teaching phases and the worked examples instruction for mathematics learning respectively. The study focuses on learning simultaneous equations and particularly on the acquisition and retention of knowledge, the conceptual and procedural knowledge acquired and retained and other students' characteristics such as gender. The data were obtained from senior secondary school students attending public co-education schools in Nigeria. This dataset consists of six different files which are obtained from two groups at three different time points.
description: There is no identifiable risk attached to the data collected
DOI: 10.48577/jpl.vtbcen
title: PropEM-L: Radio Propagation Environment Modeling and Learning for Communication-Aware Multi-Robot Exploration

description: No abstract available.
DOI: 10.48577/jpl.mmictz
title: Causes of the North-South Asymmetry in Co- seismic Ionospheric Disturbances During the 16 September 2015 Illapel M8.3 Earthquake

description: No abstract available.
DOI: 10.5281/zenodo.8198252
title: DINO4cells example single cells

description: This dataset contains 15k single cells taken from the Human Protein Project, as well as a csv file with their metadata.
DOI: 10.5281/zenodo.8198251
title: DINO4cells example single cells

description: This dataset contains 15k single cells taken from the Human Protein Project, as well as a csv file with their metadata.
DOI: 10.48577/jpl.mcvsa3
title: Modeling Near-field Co-Seismic Ionospheric Disturbances During the 16 September 2015 Illapel M8.3 Earthquake

description: No abstract available.
DOI: 10.48577/jpl.b2xesx
title: Quantum Gravity Gradiometer Technology Demo Concept

description: No abstract available.
DOI: 10.48577/jpl.c4p97d
title: From space exploration to terrestrial applications

description: No abstract available.
DOI: 10.48577/jpl.9b87wu
title: 95GHz RF-photonics Receiver for Compact Spaceborne Radars

description: No abstract available.
DOI: 10.48577/jpl.ro54ck
title: Total Electron Content Perturbations Caused by Ultra Low Frequency waves

description: No abstract available.
DOI: 10.48577/jpl.nalzjv
title: Roman Space Telescope Coronagraph technology demonstration: current status and relevance to future missions

description: No abstract available.