cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.48577/jpl.namkvr
title: Parameterization of Vegetation Scattering Albedo in the Tau-Omega Model for Soil Moisture Retrieval on Croplands

description: An accurate radiative transfer model (RTM) is essential for the retrieval of soil moisture (SM) from microwave remote sensing data, such as the passive microwave measurements from the Soil Moisture Active Passive (SMAP) mission. This mission delivers soil moisture products based upon L-band brightness temperature data, via retrieval algorithms for surface and root-zone soil moisture, the latter is retrieved using data assimilation and model support. We found that the RTM based on the tau-omega (-!) model can suer from significant errors over croplands in the simulation of brightness temperature (Tb) (in average between 􀀀9.4K and +12.0K for single channel algorithm (SCA); 􀀀8K and +9.7K for dual-channel algorithm (DCA)) if the vegetation scattering albedo (omega) is set constant and temporal variations are not considered. In order to reduce this uncertainty, we propose a time-varying parameterization of omega for the widely established zeroth order radiative transfer -! model. The main assumption is that omega can be expressed by a functional relationship between vegetation optical depth (tau) and the Green Vegetation Fraction (GVF). Assuming allometry in the tau-omega relationship, a power-law function was established and it is supported by correlating measurements of tau and GVF. With this relationship, both tau and omega increase during the development of vegetation. The application of the proposed time-varying vegetation scattering albedo results in a consistent improvement for the unbiased root mean square error of 16% for SCA and 15% for DCA. The reduction for positive and negative biases was 45% and 5% for SCA and 26% and 12% for DCA, respectively. This indicates that vegetation dynamics within croplands are better represented by a time-varying single scattering albedo. Based on these results, we anticipate that the time-varying omega within the tau-omega model will help to mitigate potential estimation errors in the current SMAP soil moisture products (SCA and DCA). Furthermore, the improved tau-omega model might serve as a more accurate observation operator for SMAP data assimilation in weather and climate prediction model.
DOI: 10.48577/jpl.ozjjl2
title: The CCSDS 123.0-B-2 “Low-complexity Lossless and Near-Lossless Multispectral and Hyperspectral Image Compression” standard, explained

description: The Consultative Committee for Space Data Systems (CCSDS) published the CCSDS 123.0-B-2 compression standard for multispectral and hyperspectral images. This standard extends the previous Issue, CCSDS 123.0-B-1, which only supported lossless compression, while maintaining backward compatibility. The main novelty of the new Issue is support for near-lossless compression, i.e., lossy compression with user-defined absolute and/or relative error limits in the reconstructed images. This new feature is achieved via closed-loop quantization of prediction errors. Two further additions arise from the new near-lossless support: first, the calculation of predicted sample values using sample representatives that may not be equal to the reconstructed sample values; second, a new hybrid entropy coder designed to provide enhanced compression performance for low-entropy data, prevalent when non-lossless compression is used. These new features enable significantly smaller compressed data volumes than those achievable with CCSDS 123.0-B-1, while controlling the quality of the decompressed images. As a result, larger amounts of valuable information can be retrieved given a set of bandwidth and energy consumption constraints.
DOI: 10.48577/jpl.ghne9u
title: Comparative Analysis of an MBSE Approach to a Traditional SE Approach for Architecting a Robotic Space System through Knowledge Categorization

description: This study seeks to compare the types and quantities of knowledge that are captured by model-based systems engineering (MBSE) and traditional architecting approaches to measure the benefits of MBSE in managing the complexity of robotic space systems. An MBSE approach was applied to architecting an orbiting sample Capture and Orient Module (COM) system concept for a Capture, Contain, and Return System (CCRS) payload concept for potential Mars Sample Return (MSR). An architecture framework was established, covering the system, subsystem, and assembly levels of the system, along with structural, behavioral, data, and requirements perspectives. The COM system architecture was captured in parallel using both MBSE and non-MBSE approaches in order to provide a side-by-side comparison of approaches. The approaches were evaluated based on how well each represented the information content of the COM system architecture. A total of 4,389 knowledge elements were classified using the Revised Bloom’s Taxonomy knowledge dimension and used to quantitatively compare the two approaches. The MBSE approach was measured to more completely capture architectural knowledge than the non-MBSE, document-based approach. Limitations to the MBSE approach were also identified, including its ability to fully represent certain high-level conceptual, procedural, and metacognitive knowledge such as design principles, design approaches and rationales, risks, development strategies and rationales, organizational core competencies, and requirement verification methods. The overall results help demonstrate the benefits of MBSE in managing the complexity of robotic space systems and strengthen the case for adopting MBSE within the broader systems engineering community.
DOI: 10.48577/jpl.mwibxg
title: Detection and tracking of tropical convective storms based on globally gridded precipitation measurements: Algorithm and Survey over the Tropics

description: This paper is the first attempt to document a simple convection tracking method based on the IMERG precipitation product to generate an IMERG-based convection tracking dataset (IMERG-CT), which provides the highest global spatio-temporal resolution of any algorithm to date. Up to now precipitation datasets have been Eulerian accumulations. Now with IMERG-CT, we can estimate total rainfall based on Lagrangian accumulations (e.g., the lifetime-accumulated precipitation amount over each convective storm), which is a very important step in diagnosing cloud-precipitation process following the evolution of air masses. Convection tracking algorithms have traditionally been developed based on cloud top temperature (CTT) from satellite infrared (IR) retrievals. However, vigorous rainfall can be produced by warm-topped systems in moist environment, which cannot be captured by traditional IR-based tracking but is observed in IMERG-CT. Therefore, an advantage of IMERG-CT is its ability to include the previously missing information of shallow clouds that grow into convective storms, which provides us more complete lifecycle records of convective storms than traditional IR-based tracking does. This study also demonstrates the utility of IMERG-CT through investigating various properties of convective systems in terms of the evolution before and after peak precipitation rate and amount. For example, composite analysis reveals a link between evolution of precipitation and convective development: the signature of stratiform anvils remaining after the storm has produced the maximum rainfall, as average CTT stays almost constant for 5 hours after the peak of precipitation. Our study highlights the importance of joint analysis of cloud and precipitation data in time sequence, which helps elucidate the underlying dynamic processes producing tropical rainfall and its resultant effects on the atmospheric thermodynamics.
DOI: 10.48577/jpl.anmtsc
title: Connecting Mem-Models with Classical Theories

description: A family of mem-models, including the mem-dashpots, mem-springs, and most recently, mem-inerters, is emerging as a new and powerful way of capturing complex nonlinear behaviors of materials and systems under various types of dynamic loads involving different frequency, amplitude, and loading histories (e.g., hysteresis). Under the framework of nonlinear state-space representation and hybrid dynamical systems, mem-springs may be formulated to effectively rep- resent an inherent degradation of material state. It is shown in this study, for the first time, how the absement (time inte- gral of strain /displacement), a signature state variable for a mem-spring, can be connected with the damage variable, a key quantity in continuum damage mechanics (CDM). The generalized momentum (time integral of stress), on the other hand, is shown to be efficient in modeling strain ratchet- ing via the concept of mem-dashpot. It is also shown in this study, for the first time, how two formulations of the mem-capacitive system models (for mem-springs) are special cases of the Preisach model.
DOI: 10.48577/jpl.p7bplm
title: Fundamental Limits of Map Relative Localization during Spacecraft Entry, Descent, and Landing

description: Map relative localization is the process of estimating the location of a lander with respect to the terrain of a celestial body. Visual or topographic maps obtained from orbit are matched with camera or LiDAR data acquired onboard the lander using correlation-based techniques. For given orbital map and descent image resolutions, terrain information content, and measurement noise, there are fundamental limits on the accuracy to which the lander can be localized. Knowledge of these limits is useful in designing and judging the optimality of an estimator, or setting realistic accuracy requirements. This paper derives and validates mathematical expressions that predict these fundamental limits. The derivation, based on application of the Cramér-Rao lower bound, exposes a maximum-likelihood estimator which is confirmed to approach the derived accuracy limits. This work will be useful in the design of future map relative localization systems, as it can be used to inform requirements on desired localization accuracy, and to determine if a near-optimal estimator has been designed.
DOI: 10.48577/jpl.ta5shc
title: Applying satellite observations of tropical cyclone internal structures to rapid intensification forecast with machine learning

description: Tropical cyclone (TC) intensity change is controlled by both environmental conditions and internal storm processes. We show that TC 24-hour subsequent intensity change (DV24) is linearly correlated with the departures in satellite observations of inner-core precipitation, ice water content and outflow temperature from respective threshold values corresponding to neutral TCs of nearly constant intensity. The threshold values vary linearly with TC intensity. Using machine learning with the inner-core precipitation and the predictors currently employed at the National Hurricane Center (NHC) for probabilistic rapid intensification (RI) forecast guidance, our model outperforms the NHC operational RI consensus in terms of the Peirce Skill Score for RI in the Atlantic basin during 2009-2014 by 37%, 12% and 138% for DV24 ≥ 25, 30 and 35 kt, respectively. Our probability of detection is 40%, 60% and 200% higher than the operational RI consensus while the false alarm ratio is only 4%, 7% and 6% higher.
DOI: 10.48577/jpl.jn7mfl
title: Draft Genome Sequences of Klebsiella Species Isolated from the International Space Station

description: Isolated across four unique locations aboard the International Space Station (ISS), 10 bacterial strains were compared using a whole-genome sequence (WGS) analysis and phylogenetically identified as Klebsiella. The WGS will aid in genomic datamining the ISS Klebsiella strains with Earth counterparts and gain insights about their adaptation to space conditions.
DOI: 10.48577/jpl.ocecmf
title: Diffusion length and mobility in mid-wavelength InAs/InAsSb superlattice infrared detectors

description: In the last decade the infrared detectors with InAs/InAsSb (Gallium-free) type-II strained layer superlattice (T2SLS) absorbers became technology of interest for many imaging applications. In this work we studied dependence of minority carrier (holes), absorption coefficient and Quantum Efficiency (QE) of 5.6 µm cut-off wavelength MWIR InAs/InAsSb detectors on temperatures and applied bias. We found that the minority carrier lifetime is very long,   5.5 µs, and is temperature independent in the temperature range T = 50 – 150K. The QE without anti-reflection coating for a back side illumination increases from QE  0.3 at T = 50K to QE  0.6 at T = 180K. The minority carriers holes diffusion length, Ldh, was found from QE and absorption coefficient. The hole diffusion length, Ldh =2.4 m at T = 50 K and monotonically increases to Ldh= 7.2 m at T = 180 K. The hole mobility, calculated from diffusion length and minority carrier lifetime is h = 4.5 cm/Vs at T = 50K and increases with temperature reaching h = 7.2 cm/Vs at T = 150K.
DOI: 10.48577/jpl.oupiik
title: 1st Adiabatic Invariants and Phase Space Densities for the Jovian Electron and Proton Radiation Belts—Galileo and GIRE3 Estimates

description: The fluxes and phase space densities for a fixed 1st adiabatic invariant for high energy electrons and protons provide important input data for a variety of scientific studies for determining the physics of particle diffusion and energization. This study addresses these issues for the jovian environment by providing estimates of the 1st adiabatic invariant and phase space density based on the large data base available from the APL/JHU EPD charged particle detector on Galileo. This is the first time where the EPD high energy data set collected over the entire mission duration has been used for this purpose. Thus, this paper provides insight into the long term (~7 years) dynamics of the high energy electron and proton environment at Jupiter which has not been studied in its entirety before. To be specific, 10 minute averages of the high energy EPD electron and proton data are used to compute electron and proton differential flux spectra versus energy between L=~8 and L=25 L over the Galileo mission. These spectra provide estimates of the differential fluxes and phase space density for constant 1st adiabatic invariants between 102 MeV/G to 105 MeV/G. As would be expected from previous studies, the electron and proton fluxes and phase space densities generally trend lower as the planet is approached. The results indicate that, whereas the overall trends for each orbit are consistent, detailed orbit to orbit variations can be observed. Galileo orbit C22 is presented as a specific example of deviations from the mean downward trend. To validate the Galileo results and extend the findings into 3 L, the GIRE3 model, which is an amalgam of synchrotron measurements and Pioneer, Voyager, and Galileo in-situ data, was also used to compute the fluxes and phase space densities for constant 1st adiabatic invariant versus L-shell. In addition, the GIRE3 flux contours at constant energy were converted to phase space densities to estimate the applicable range of the data and model. Comparing the GIRE3 and Galileo findings demonstrates that, while the model adequately reproduces the EPD data trends, it shows additional variations near Io. Though the agreement between the data and model is not unexpected as the model is based in part on the Galileo data, it provides proof that the GIRE3 is a useful starting point for diffusion analyses and similar studies.
DOI: 10.48577/jpl.zbalmp
title: Draft Genome Sequences of Lactobacillales Isolated from the International Space Station

description: Nineteen strains from the Order Lactobacillales were isolated from the International Space Station and Crew Resupply Vehicle, and whole-genome sequences (WGS) were generated. WGS would permit the characterization of these potential pathogenic bacteria that have been adapting to the extreme conditions of the space environment.
DOI: 10.48577/jpl.qtqkzk
title: Observing Planetary and Pre-Planetary Nebulae with the James Webb Space Telescope

description: Most stars in the Universe that leave the main sequence in a Hubble time will endtheir lives evolving through the Planetary Nebula (PN) evolutionary phase. The heavy mass losswhich occurs during the preceding Asymptotic Giant Branch (AGB) phase is important acrossastrophysics, dramatically changing the course of stellar evolution, contributing to the dust contentof the interstellar medium, and influencing its chemical composition. The evolution from the AGBphase to the PN phases remains poorly understood, especially the dramatic transformation thatoccurs in the morphology of the mass-ejecta as AGB stars enter the post-AGB phase and their roundcircumstellar envelopes evolve into pre-PNe (PPNe) and then to PNe. The majority of PPNe and PNedeviate strongly from spherical symmetry. Strong binary interactions most likely play a fundamentalrole in influencing this evolutionary phase, but the details of these interactions remain shrouded inmystery. Thus, understanding the formation and evolution of these objects is of wide astrophysicalimportance. PNe have long been known to emit across a very large span of wavelengths, from theradio to X-rays. Extensive use of space-based observatories at X-ray (Chandra/ XMM-Newton),optical (HST) and mid- to far-infrared (Spitzer, Herschel) wavelengths in recent years has producedsignificant new advances in our knowledge of these objects. Given the expected advent of theJames Webb Space Telescope (JWST) in the near future, we focus on future high-angular-resolution,high-sensitivity observations at near and mid-IR wavelengths with JWST that can help in addressingthe major unsolved problems in the study of PNe and their progenitors.
DOI: 10.48577/jpl.zqwt1b
title: Evaluating the Absolute Calibration Accuracy and Stability of AIRS using the CMC SST

description: We compare the daily mean and standard deviation of the difference between the Sea Surface skin Temperature (SST) derived from clear Atmospheric InfraRed Sounder (AIRS) data from seven atmospheric window channels between 2002 and 2020 and collocated Canadian Meteorological Centre (CMC) SST data from the tropical oceans. After correcting the mean difference for cloud contamination and diurnal effects, the remaining bias relative to the CMC SST, is not inconsistent with estimates of the AIRS absolute accuracy based on the uncertainty of the pre-launch calibration. The time series of the bias produces trends well below the 10 mK/yr level required for climate change evaluations. The trends are in the 2 mK/yr range for the five window channels between 790 and 1231 cm-1, and +5 mK/yr for the shortwave channels. Between 2002 and 2020 the time series of the standard deviation of the difference between the AIRS SST and the CMC SST shows the effects of version changes in the CMC SST, but dropped fairly steadily to below 0.4 K in several AIRS window channels, a level previously only seen in SST models relative to the Argo buoys.
DOI: 10.48577/jpl.5nkttp
title: Vertical controlled landing on 67P / Churyumov-Gerasimenko

description: With the increasing interest of small body science due to its important role in the puzzle of the solar system formation, missions to small bodies are studied and developed in preparation for future exploration. Together with the operational experience gained and the general rapid technology development, landers and surface mobility elements enable more and more an enhancement of the scientific mission return by collecting in-situ measurements or samples of the surface. Hence, the descent and landing operations become a vital part in a successful execution of the mission. In this paper, a descent strategy for a vertical landing on small bodies is presented. A controlled descent and landing sequence is proposed as opposed to ballistic descents used in previous small body landers (Ulamec and Biele, 2009). The analysis aims for a generic investigation of the surface accessibility of a small body on the example of the comet 67P/Churyumov-Gerasimenko. A vertical controlled descent trajectory concept is proposed and applied to all surface facets of the downscaled ESA polyhedron shape model (released in 2015 (ESA, 2015)). The trajectories are assessed by their duration of descent, need and their surface accessibility with respect to safety distances to the surface and the canyon walls. The analysis results in Delta v need ranges between 0.7 m/s and 3.1 m/s, the duration of descent between 65 min and 275 min. If a minimum distance of 175 m to the canyon surface or walls is considered as safe, 90% of the comet's surface is accessible with the described implemented strategy.
DOI: 10.48577/jpl.uoa7f4
title: Ambient Noise Tomography with Common Receiver Clusters in Distributed Sensor Network

description: Abstract—Near-surface imaging with distributed sensor networks (DSN) is promising for planet exploration, which affordably generates a near-surface velocity model. Recently, an Eikonal tomography-based ambient noise seismic imaging (ANSI) algorithm was implemented in a DSN to realize real-time and in-situ near-surface imaging. However, only using data from neighbors to generate a velocity map cannot have enough stacking samples to generate high-quality results. Also, the neighbor range increase will result in the exponential rise of communication costs. To overcome this problem, we propose a new decentralized Eikonal tomography algorithm in the DSN. The main idea is to change the source-based algorithm to a receiver-based one, which we call common receiver decentralized Eikonal tomography (CRTomoEK). With CR-TomoEK, nodes fully utilize signals from neighbors to generate partial velocity maps, when combined, lead to the final output. When compared with the original Eikonal algorithm, the stacking number is significantly increased, output quality is higher than before, and there is a significant reduction in communication cost. We performed experiments on both synthetic data and real data from the USArray Transportable Array. Both imaging quality and communication cost are considered in the algorithm validation. The result shows that our algorithm significantly increases the output quality while keeping the communication cost safe to generate a real-time result.
DOI: 10.48577/jpl.6ir6va
title: Europa Clipper preparatory photometry to constrain surface properties

description: We infer the surface reflectance properties of Europa using multi-spectral data-sets available from previous missions. We use 21 full disk images of Europa from Voyager’s Imaging Science System (ISS), Galileo’s Solid State Imaging (SSI), and New Horizons’ LOng Range Reconnaissance Imager (LORRI) at differing observation geometries (10◦ - 128◦ (phase angle)) to compute disk integrated surface scattering properties over various geologic units. The derived empirical photometric models will serve the practical goals of data acquisition, aid in the calculation of instrument integration times, and facilitate quick look data products for images acquired by Europa Clipper and other future missions to Europa. We use the Minneart and Lommel-Seeliger plus Lambert reflectance models to constrain the photometric parameters of Europa’s surface. We find that the surface albedo parameter, B0, in the Minneart function gradually decreases with increasing phase angles. We also note that the photometric properties of Europa (geometric albedo - at 0.47µm is 0.72 on the leading side and 0.62 on the trailing side) require a significant ‘Lambert’ term (A&lt;1) in the Lommel-Seeliger plus Lambert reflectance model. We also observe that the photometric parameters are not highly dependent on the geologic terrain type despite their visibly different albedos.