AndreaBozzo/ceres-open-data-index huggingface dataset:
Physics of Failure Models for Capacitor Degradation in DC-DC Converters

This paper proposes a combined energy-based model with an empirical physics of failure model for degradation analysis and prognosis of electrolytic capacitors in DC-DC power converters. Electrolytic capacitors and MOSFET’s have higher failure rates than other components in DC-DC converter systems. For example, in avionics systems where the power supply drives a GPS unit, ripple currents can cause glitches in the GPS position and velocity output, and this may cause errors in the Inertial Navigation (INAV) system causing the aircraft to fly off course. We have employed a topological energy based modeling scheme based on the bond graph (BG) modeling language for building parametric models of electrical domain systems. Our current work adopts a physics of failure model (Arrhenius Law) for equivalent series resistance (ESR) increase in electrolytic capacitors subjected to electrical and thermal stresses. Experiments for capacitor degradation were conducted for collecting degradation ESR data. Parameter re-estimation for the failure model is done using the experimental data. The derived degradation model of the capacitor is reintroduced into the DC-DC converter system model to study changes in the system performance using Monte Carlo simulation methods. Stochastic simulation methods applied to the combined model help us predict how system performance deteriorates with time.

Tags: ames, dashlink, nasa
Organization: National Aeronautics and Space Administration
Networked Instrumentation Element

&lt;p&gt;Armstrong researchers have developed a networked instrumentation system that connects modern experimental payloads to existing analog and digital communications infrastructures. In airborne applications, this system enables a cost-effective, long-range, line-of-sight network link over the S and L frequency bands that supports data rates up to 10 megabits per second (Mbps) and a practically unlimited number of independent data streams. The resulting real-time payload link allows researchers to make in-flight adjustments to experimental parameters, increasing overall data quality and eliminating the need to repeat flights.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Work to date&lt;/strong&gt;: The team has developed and flight-tested the 10 Mbps bi-direction aircraft-to-ground, line-of-sight network. A follow-on project, Space-Based Range Demonstration and Certification (SBRDC) Flight Demonstration #2, involved integration of this system with a phased-array antenna and controller to provide a 10 Mbps over-the-horizon network downlink. This prototype system was further refined into a more operational system that provided the Airborne Research Test System (ARTS) aboard the Full-Scale Advanced Systems Testbed (FAST) access to thousands of parameters from the heavily instrumented aircraft. Engineers were able to view ARTS network data output in the control room, without replacing any aircraft instrumentation or ground equipment.&amp;nbsp; Additionally, four streams of network data from onboard hot-film sensors was recorded onboard and transmitted to the control room.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Looking ahead&lt;/strong&gt;: Work has begun to design a new system that incorporates state-of-the-art transceiver technology. The new system is expected to allow a five-fold improvement in throughput, to 40 Mbps.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Benefits&lt;/strong&gt;&lt;/p&gt;&lt;ul&gt;&lt;li&gt;&lt;strong&gt;Flexible&lt;/strong&gt;: Expands the utility of existing airborne platforms with legacy communications systems by supporting state-of-the-art payloads that leverage current network technology&lt;/li&gt;&lt;li&gt;&lt;strong&gt;Economical&lt;/strong&gt;: Achieves a bi-directional, line-of-sight network without the need to replace existing communications infrastructure&lt;/li&gt;&lt;li&gt;&lt;strong&gt;Flight efficient&lt;/strong&gt;: With real-time control of experimental parameters, reduces the need for repeat flights&lt;/li&gt;&lt;/ul&gt;&lt;p&gt;&lt;strong&gt;Applications&lt;/strong&gt;&lt;/p&gt;&lt;ul&gt;&lt;li&gt;Secure local line-of-sight communications&lt;/li&gt;&lt;li&gt;Global space-based communications via satellite links&lt;/li&gt;&lt;/ul&gt;

Tags: active, armstrong-flight-research-center, element
Organization: National Aeronautics and Space Administration
Near-Real-Time SSM/I-SSMIS EASE-Grid Daily Global Ice Concentration and Snow Extent V003

The Near-real-time Ice and Snow Extent (NISE) data set provides daily, global maps of sea ice concentrations and snow extent. These data are not suitable for time series, anomalies, or trends analyses. They are meant to provide a best estimate of current ice and snow conditions based on information and algorithms available at the time the data are acquired. Near-real-time products are not intended for operational use in assessing sea ice conditions for navigation.

This NISE Version 3 product contains DMSP-F16, SSMIS-derived sea ice concentrations and snow extents derived from the Special Sensor Microwave Imager/Sounder (SSMIS) aboard the Defense Meteorological Satellite Program (DMSP) F16 satellite. For DMSP-F18, SSMIS-derived data, see <a href="https://doi.org/10.5067/3KB2JPLFPK3R">NISE Version 5</a>. For DMSP-F17, SSMIS-derived data, see <a href="https://nsidc.org/data/nise/versions/4">NISE Version 4</a>. For the older, DMSP-F13, Special Sensor Microwave Imager (SSMI) derived data, see <a href="https://doi.org/10.5067/4FSODMDM1WEJ">NISE Version 2</a>.

Tags: cryosphere, earth-science, sea-ice, snow-ice
Organization: National Aeronautics and Space Administration
Ground-Based Global Navigation Satellite System (GNSS) GPS real-time POD Clock Corrections  (60-second sampling, 60-second files) from NASA CDDIS

This product contains a time series of clock biases for healthy satellites in the GPS constellation that are accumulated every minute throughout the day. In addition, formal 1-sigma uncertainties for the corrections are provided. The product is generated at JPL's Global Differential GPS Operations Centers in real-time. The data in this product can be concatenated with other daily products to provide larger coverage in time.

Tags: earth-science, geodetics, gravity-gravitational-field, solid-earth, tectonics
Organization: National Aeronautics and Space Administration
MODIS/Aqua Snow Cover Monthly L3 Global 0.05Deg CMG V061

This global Level-3 (L3) data set provides monthly average snow cover within 0.05° (approx. 5 km) MODIS Climate Modeling Grid (CMG) cells. Monthly averages are computed from daily snow cover observations in the MODIS/Aqua Snow Cover Daily L3 Global 0.05Deg CMG (https://doi.org/10.5067/MODIS/MYD10CM.061) data set.

The terms "Version 61" and "Collection 6.1" are used interchangeably in reference to this release of MODIS data.

Tags: cryosphere, earth-science, national-geospatial-data-asset, ngda, snow-ice
Organization: National Aeronautics and Space Administration
Anomaly Detection from ASRS Databases of Textual Reports

Our primary goal is to automatically analyze textual reports from the Aviation Safety Reporting System (ASRS) database to detect/discover the anomaly categories reported by the pilots, and to assign each report to the appropriate category/categories. We have used two state-of-the-art models for text analysis: (i) mixture of von Mises Fisher (movMF) distributions, and (ii) latent Dirichlet allocation (LDA) on a subset of all ASRS reports. The models achieve a reasonably high performance in discovering anomaly categories and clustering reports. Each category is represented by the most representative words with the highest probability in this category. In addition, since the inference algorithm for LDA was somewhat slow, we have developed a new fast LDA algorithm which is 5-10 times more efficient than the original one, therefore more applicable for the practical use. Further, we have developed a simple visualization tool based on non-linear manifold embedding (ISOMAP) to generate a 2-d visual representation of each report based on its content/topics, which gives a direct view of the structure of the whole dataset as well as the outliers.

Tags: ames, dashlink, nasa
Organization: National Aeronautics and Space Administration
A Modeling Framework for Prognostic Decision Making and its Application to UAV Mission Planning

The goal of prognostic decision making (PDM) is to utilize information on anticipated system health changes in selecting future actions. One of the key challenges in PDM is finding a sufficiently expressive yet compact mathematical representation of the system for use with decision optimization algorithms. In this paper we describe a general modeling approach for a class of PDM problems with non-linear system degradation processes and uncertainties in state estimation, action effects, and future operating conditions. The approach is based on continuous Partially Observable Markov Decision Processes (POMDPs) used in conjunction with 'black box' system simulations. The proposed modeling framework can be cast into simpler representations, depending on which sources of uncertainty are being included. The approach is illustrated with a mission planning case study for an unmanned aerial vehicle (UAV). In the case study a PDM system is tasked with optimizing the vehicle route after an in-flight component fault is detected. A stochastic algorithm (based on particle filtering) is used for decision optimization, with a second, deterministic algorithm providing a performance evaluation baseline. Both algorithms utilize a UAV physics simulator for generating predictions of future vehicle states. Performance benchmarking is done on a set of mission scenarios of increasing complexity.

Tags: ames, dashlink, nasa
Organization: National Aeronautics and Space Administration
High Mountain Asia Langtang Shortwave Downward Irradiance V001

This data set contains thermal-dome-corrected downward shortwave irradiance at the bottom of atmosphere, measured by the Shared Mobile Atmospheric Research and Teaching Radar (SMART-R) and collected by the International Centre for Integrated Mountain Development (ICIMOD).

Tags: atmosphere, atmospheric-radiation, earth-science
Organization: National Aeronautics and Space Administration
Exploring the Model Design Space for Battery Health Management

Battery Health Management (BHM) is a core enabling technology for the success and widespread adoption of the emerging electric vehicles of today. Although battery chemistries have been studied in detail in literature, an accurate run-time battery life prediction algorithm has eluded us. Current reliability-based techniques are insufficient to manage the use of such batteries when they are an active power source with frequently varying loads in uncertain environments. The amount of usable charge of a battery for a given discharge profile is not only dependent on the starting state-of-charge (SOC), but also other factors like battery health and the discharge or load profile imposed. This paper presents a Particle Filter (PF) based BHM framework with plug-and-play modules for battery models and uncertainty management. The batteries are modeled at three different levels of granularity with associated uncertainty distributions, encoding the basic electrochemical processes of a Lithium-polymer battery. The effects of different choices in the model design space are explored in the context of prediction performance in an electric unmanned aerial vehicle (UAV) application with emulated flight profiles.

Tags: ames, dashlink, nasa
Organization: National Aeronautics and Space Administration
Sentinel-3A OLCI Level-1B Earth-observation Full Resolution (EFR) Data, version 1

The Ocean and Land Colour Instrument (OLCI) is the successor to ENVISAT's Medium Resolution Imaging Spectrometer (MERIS) having additional spectral channels, different camera arrangements and simplified on-board processing. The OLCI is a push-broom instrument with five camera modules sharing the field of view. The field of view of the five cameras is arranged in a fan-shaped configuration in the vertical plane, perpendicular to the platform velocity. Each camera has an individual field of view of 14.2&#176; and a 0.6&#176; overlap with its neighbors. The whole field of view is shifted across track by 12.6 degrees away from the sun to minimize the impact of sun glint. OLCI is equipped with on-board calibration hardware based on sun diffusers. There are three sun diffusers--two 'white' diffusers dedicated to radiometric calibration and one dedicated to spectral calibration, with spectral reflectance features. The native resolution is approximately 300m, referred to as Full Resolution (FR). A Reduced Resolution (RR) processing mode provides Level-1B data at sampling rates decreased by a factor of four in both spatial dimensions resulting to resolution of approximately 1.2 km.

Tags: atmosphere, atmospheric-radiation, earth-science
Organization: National Aeronautics and Space Administration
ANALYZING AVIATION SAFETY REPORTS: FROM TOPIC MODELING TO SCALABLE MULTI-LABEL CLASSIFICATION

ANALYZING AVIATION SAFETY REPORTS: FROM TOPIC MODELING TO
SCALABLE MULTI-LABEL CLASSIFICATION

AMRUDIN AGOVIC*, HANHUAI SHAN*, AND ARINDAM BANERJEE*

Abstract. The Aviation Safety Reporting System (ASRS) is used to collect voluntarily submitted
aviation safety reports from pilots, controllers and others. As such it is particularly useful
in researching aviation safety deficiencies. In this paper we address two challenges related to the
analysis of ASRS data: (1) the unsupervised extraction of meaningful and interpretable topics
from ASRS reports and (2) multi-label classification of ASRS data based on a set of predefined
categories. For topic modeling we investigate the practical usefulness of Latent Dirichlet Allocation
(LDA) when it comes to modeling ASRS reports in terms of interpretable topics. We also
utilize LDA to generate a more compact representation of ASRS reports to be used in multi-label
classification. For multi-label classification we propose a novel and highly scalable multi-label classification
algorithm based on multi-variate regression. Empirical results indicate that our approach
is superior to several baseline and state-of-the-art approaches.

Tags: ames, dashlink, nasa
Organization: National Aeronautics and Space Administration
CDDIS_GNSS_products_positions

Weekly station positions and velocity solutions in Software INdependent EXchange (SINEX) format derived from analysis of Global Navigation Satellite System (GNSS) data. These products are the generated by analysis centers in support of the International GNSS Service (IGS) and combined by the IGS reference frame coordinator to form the official IGS station position product (weekly).

Tags: nasa
Organization: National Aeronautics and Space Administration
Landsat Level-1 Collection 2

The Landsat Level-1 Collection 2 products, produced by the U.S. Geological Survey (USGS), provide high-quality, calibrated, and georeferenced satellite data that support a wide range of remote sensing applications. This dataset encompasses multispectral data captured by the Landsat 1-9 missions, spanning the period from 1972 to present and offers consistent and accurate measurements of Earth's land surface characteristics. These data  are processed to established precise standards, meaning they are radiometrically and geometrically calibrated to ensure high accuracy for scientific analyses. The Level-1 products include per-pixel quality assessment information that provides essential metadata to help users select the most suitable data for their needs.

Tags: earth-science, land-surface, surface-radiative-properties
Organization: National Aeronautics and Space Administration
Prognostics of Power MOSFET

This paper demonstrates how to apply prognostics to power MOSFETs (metal oxide field effect transistor). The methodology uses thermal cycling to age devices and Gaussian process regression to perform prognostics. The approach is validated with experiments on 100V power MOSFETs. The failure mechanism for the stress conditions is determined to be die-attachment degradation. Change in ON-state resistance is used as a precursor of failure due to its dependence on junction temperature. The experimental data is augmented with a finite element analysis simulation that is based on a two-transistor model. The simulation assists in the interpretation of the degradation phenomena and SOA (safe operation area) change.

Tags: ames, dashlink, nasa
Organization: National Aeronautics and Space Administration
International Space Station SERVIR Environmental Research and Visualization System V1

Abstract: The ISS SERVIR Environmental Research and Visualization System (ISERV) acquired images of the Earth's surface from the International Space Station (ISS). The goal was to improve automatic image capturing and data transfer. ISERV's main component was the optical assembly which consisted of a 9.25 inch Schmidt-Cassegrain telescope, a focal reducer (field of view enlarger), a digital single lens reflex camera, and a high precision focusing mechanism. A motorized 2-axis pointing mount allowed pointing at targets approximately 23 degrees from nadir in both along- and across-track directions.

Tags: earth-science, spectral-engineering, visible-wavelengths
Organization: National Aeronautics and Space Administration
Level 2.0 Almucantar Inversion Products (except phase functions)

AERONET inversion code provides aerosoloptical properties in the total atmospheric column derived from the direct and diffuse radiation measured byAERONETCimel sun/sky-radiometers. AERONET inversion developmentand researchactivitiesare described in the papers by Dubovik and King, [2000], Dubovik et al. [2000], Dubovik et al. [2002a], Dubovik et al. [2002b], Dubovik et al., [2006a], Sinyuk et al. [2006]. The Version 2(V2)inversion (or retrieval)products are summarized below. These products are available through the internal analysis system&#x0022;demonstrat&#x0022; and the AERONET website. Adetailed description of V2 AERONET retrieval will be provided in the paper by Dubovik et al., [2006b].

Tags: aerosols, clouds, earth-science, inversions, precipitable-water, radiation, satellite
Organization: National Aeronautics and Space Administration
SASSIE Arctic Field Campaign Drifter Hydrography Data Fall 2022 Version 2p

The Salinity and Stratification at the Sea Ice Edge (SASSIE) project is a NASA experiment that aims to understand how salinity anomalies in the upper ocean generated by melting sea ice affect sea surface temperature (SST), stratification, and subsequent sea-ice growth. SASSIE involved a field campaign that sampled the transition from summer melt to autumn ice advance in the Beaufort Sea during August-October 2022, making intensive in situ and remote sensing observations within ~200 km of the sea ice edge.  This dataset contains ocean temperature and salinity data collected by surface drifting buoys (called UpTempO or Hydrobuoys, interchangeably) deployed in the Beaufort Sea.  Each buoy has a different configuration of sensors, and records to a maximum of 60 m depth. Drifters were left at sea after the completion of the field deployment and are recording data into March 2023. Version 2p data has major quality control performed. Data are available in netCDF format.

Tags: earth-science, ocean-temperature, oceans, salinity-density
Organization: National Aeronautics and Space Administration
Gazetteer of Planetary Nomenclature: Asteroids: Gaspra Craters

These images display asteriods documented and approved by the International Astronomical Union (IAU).

Tags: asteriods, dactyl, eros, gaspra, ida, imagery, images, itokawa, lutetia, mathilde, steins, usgs, vesta, working-group-for-planetary-system-nomenclature
Organization: National Aeronautics and Space Administration
Formal Specification and Verification of a Coordination Protocol for an Automated Air Traffic Control System

We detail all of the facets of adapting classical model checking to a real aerospace system, in- cluding deriving the formal model and a set of specifications from natural language descriptions. To ensure the model checking results are meaningful, we have to ensure that both the model and specifications correctly reflect the intentions of the designers, thus we employ model validation and property debugging techniques. We demonstrate the utility of enhancing LTL satisfiability checking by taking the fairness constraints of the system model into consideration. We argue that specification debugging in real applications deserves more attention in future research efforts, and the utility of a system formalization, model and specification debugging, and verification trilogy for model checking real systems under development.
In this paper we assume there are no hardware failures or lost messages. As the AAC design develops and hardware details are decided by AAC designers, we plan to take the failure rates of the chosen components into consideration, i.e. by extending our work to probabilistic model checking using PRISM [19]. Previous work has reported on analyzing the safety of air traffic control systems using simulation [3] or fault trees [1]. By extending the model we designed in this paper, we can carry out safety analysis using PRISM to capture the dynamic interactions in the AAC.

Tags: ames, dashlink, nasa
Organization: National Aeronautics and Space Administration
Sentinel-1 Single Look Complex (SLC) Bursts

Sentinel-1 Interferometric Wide (IW) and Extra Wide (EW) swath modes are collected using a form of ScanSAR imaging called Terrain Observation with Progressive Scans SAR (TOPSAR). With TOPSAR data is acquired in bursts by cyclically switching the antenna beam between multiple adjacent sub-swaths. Sentinel-1 Single Look Complex (SLC) products contain one image per sub-swath and one per polarization channel. Each sub-swath image consists of a series of overlapping bursts, where each burst has been processed as a separate SLC image. The Sentinel-1 Single Look Complex (SLC) Bursts collection identifies each burst from an individual IW or EW SLC product. The granule metadata describes the burst and provides links to a service which extracts the burst image from the SLC product and returns a GeoTIFF file. A link is also provided to the same service to extract the supplemental metadata files from the SLC product and return an XML file. The granules in the collection are generated for the life of the Sentinel-1 mission and include both Sentinel-1A and Sentinel-1B SLC products from both the IW and EW mode.

Tags: coastal-processes, cryosphere, earth-science, geomorphic-landforms-processes, glaciers-ice-sheets, land-surface, oceans, solid-earth, tectonics
Organization: National Aeronautics and Space Administration
Aerial Photo Single Frames

The Aerial Photography Single Frame Records collection is a large and diverse group of imagery acquired by Federal organizations from 1937 to the present. Over 6.4 million frames of photographic images are available for download as medium and high resolution digital products. The high resolution data provide access to photogrammetric quality scans of aerial photographs with sufficient resolution to reveal landscape detail and to facilitate the interpretability of landscape features. Coverage is predominantly over the United States and includes portions of Central America and Puerto Rico. Individual photographs vary in scale, size, film type, quality, and coverage.

Tags: earth-science, land-surface, surface-radiative-properties, topography
Organization: National Aeronautics and Space Administration