AndreaBozzo/ceres-open-data-index huggingface dataset:
Prognostics Of Power Mosfets Under Thermal Stress Accelerated Aging Using Data-Driven And Model-Based Methodologies

An approach for predicting remaining useful life of power MOSFETs (metal oxide field effect transistor) devices has been developed. Power MOSFETs are semiconductor switching devices that are instrumental in electronics equipment such as those used in operation and control of modern aircraft and spacecraft. The MOSFETs examined here were aged under thermal overstress in a controlled experiment and continuous performance degradation data were collected from the accelerated aging experiment. Die-attach degradation was determined to be the primary failure mode. The collected run-to-failure data were analyzed and it was revealed that ON-state resistance increased as die-attach degraded under high thermal stresses. Results from finite element simulation analysis support the observations from the experimental data. Data-driven and model based prognostics algorithms were investigated where ON-state resistance was used as the primary precursor of failure feature. A Gaussian process regression algorithm was explored as an example for a data-driven technique and an extended Kalman filter and a particle filter were used as examples for model-based techniques. Both methods were able to provide valid results. Prognostic performance metrics were employed to evaluate and compare the algorithms.

Tags: ames, dashlink, nasa
Organization: National Aeronautics and Space Administration
Center Innovation Fund: KSC CIF Program

&lt;p&gt;Each individual NASA Center has full discretion on the use of the funds and the Center Chief Technologists coordinates a competitive process at their Center for the selection of projects.&amp;nbsp;Kennedy Space Center (KSC) considers CIF very important because it encourages employees to develop innovative concepts that, if successful, can solve future mission needs. As in prior years, KSC put a strong emphasis on low Technology Readiness Level (TRL) technologies for CIF in support of Space Technology Area Roadmaps that align with KSC core capabilities.&lt;/p&gt;&lt;p&gt;KSC has emphasized partnerships for several years and has benefited in many ways from the other NASA centers and government agencies, academia and industry collaborations. In keeping with this emphasis, a key selection criterion for KSC CIF relates to collaborations and partnerships (with leveraged funding).&amp;nbsp;&lt;/p&gt;

Tags: active, kennedy-space-center, ksc-cif, program
Organization: National Aeronautics and Space Administration
ATLAS/ICESat-2 L3B Slope-Corrected Land Ice Height Time Series V006

This data set provides time series of land-ice surface heights derived from the ICESat-2 ATL06 Land Ice Height product. It is intended primarily as an input for higher level gridded products but can also be used on its own as a spatially organized product that allows easy access to height-change information derived from ICESat-2 observations.

Tags: cryosphere, earth-science, glaciers-ice-sheets
Organization: National Aeronautics and Space Administration
Mining Distance-Based Outliers in Near Linear Time

Full title: Mining Distance-Based Outliers in Near Linear Time with Randomization and a Simple Pruning Rule

Abstract: Defining outliers by their distance to neighboring examples is a popular approach to finding unusual examples in a data set. Recently, much work has been conducted with the goal of finding fast algorithms for this task. We show that a simple nested loop algorithm that in the worst case is quadratic can give near linear time performance when the data is in random order and a simple pruning rule is used. We test our algorithm on real high-dimensional data sets with millions of examples and show that the near linear scaling holds over several orders of magnitude. Our average case analysis suggests that much of the efficiency is because the time to process non-outliers, which are the majority of examples, does not depend on the size of the data set.

Tags: ames, dashlink, nasa
Organization: National Aeronautics and Space Administration
A Model-based Prognostics Approach Applied to Pneumatic Valves

Within the area of systems health management, the task of prognostics centers on predicting when components will fail. Model-based prognostics exploits domain knowledge of the system, its components, and how they fail by casting the underlying physical phenomena in a physics-based model that is derived from first principles. Uncertainty cannot be avoided in prediction, therefore, algorithms are employed that help in managing these uncertainties. The particle filtering algorithm has become a popular choice for model-based prognostics due to its wide applicability, ease of implementation, and support for uncertainty management. We develop a general model-based prognostics methodology within a robust probabilistic framework using particle filters. As a case study, we consider a pneumatic valve from the Space Shuttle cryogenic refueling system. We develop a detailed physics-based model of the pneumatic valve, and perform comprehensive simulation experiments to illustrate our prognostics approach and evaluate its effectiveness and robustness. The approach is demonstrated using historical pneumatic valve data from the refueling system.

Tags: ames, dashlink, nasa
Organization: National Aeronautics and Space Administration
Terra MODIS Level-3 Global Mapped 4µm Nighttime Sea Surface Temperature (SST4) Data, version R2019.0

MODIS (or Moderate-Resolution Imaging Spectroradiometer) is a key instrument aboard the Terra (EOS AM) and Aqua (EOS PM) satellites. Terra's orbit around the Earth is timed so that it passes from north to south across the equator in the morning, while Aqua passes south to north over the equator in the afternoon. Terra MODIS and Aqua MODIS are viewing the entire Earth's surface every 1 to 2 days, acquiring data in 36 spectral bands, or groups of wavelengths (see MODIS Technical Specifications). These data will improve our understanding of global dynamics and processes occurring on the land, in the oceans, and in the lower atmosphere. MODIS is playing a vital role in the development of validated, global, interactive Earth system models able to predict global change accurately enough to assist policy makers in making sound decisions concerning the protection of our environment.

Tags: earth-science, national-geospatial-data-asset, ngda, ocean-temperature, oceans
Organization: National Aeronautics and Space Administration
Prognostication of Residual Life and Latent Damage Assessment in Lead-free Electronics Under Thermo-Mechanical Loads

Requirements for system availability for ultra-high reliability electronic systems such as airborne and space electronic systems are driving the need for advanced heath monitoring techniques for early detection of the onset of damage. Aerospace-electronic systems usually face a very harsh environment, requiring them to survive the high strain rates, e.g. during launch and re-entry and thermal environments including extreme low and high temperatures. Traditional health monitoring methodologies have relied on reactive methods of failure detection often providing little or no insight into the remaining useful life of the system. In this paper, a mathematical approach for interrogation of system state under cyclic thermo- mechanical stresses has been developed for 6-different leadfree solder alloy systems. Data has been collected for leading indicators of failure for alloy systems including, Sn3Ag0.5Cu, Sn3Ag0.7Cu, Sn1Ag0.5Cu, Sn0.3Ag0.5Cu0.1Bi, Sn0.2Ag0.5Cu0.1Bi0.1Ni, 96.5Sn3.5Ag second-level interconnects under the application of cyclic thermo-mechanical loads. Methodology presented resides in the pre-failure space of the system in which no macro-indicators such as cracks or delamination exist. Systems subjected to thermo-mechanical damage have been interrogated for system state and the computed damage state correlated with known imposed damage. The approach involves the use of condition monitoring devices which can be interrogated for damage proxies at finite time- intervals. Interrogation techniques are based on derivation of damage proxies, and system prior damage based non-linear least- squares methods including the Levenberg-Marquardt Algorithm. The system’s residual life is computed based on residual-life computation algorithms.

Tags: ames, dashlink, nasa
Organization: National Aeronautics and Space Administration
High Mountain Asia MAR V3.5 Regional Climate Model Output V001

This data set provides modeled surface and atmospheric fields from the Modèle Atmosphérique Régionale (MAR) regional climate model (version 3.5) over the Himalayan region at 10 km spatial resolution. Modeled parameters include surface mass and energy balance components, near-surface atmospheric properties, and snowpack properties.

Tags: atmosphere, atmospheric-radiation, atmospheric-winds, earth-science, land-surface, snow-ice, surface-thermal-properties, terrestrial-hydrosphere
Organization: National Aeronautics and Space Administration
AMSR-E/Aqua Monthly L3 Global Ascending/Descending .25x.25 deg Ocean Grids V002

The Level-3 daily product (AE_DyOcn), weekly product (AE_WkOcn), and monthly product (AE_MoOcn) include SST, near-surface wind speed, columnar water vapor, and columnar cloud liquid water over oceans in a 0.25 degree by 0.25 degree grid, generated from AE_Ocean.

Tags: atmosphere, atmospheric-water-vapor, atmospheric-winds, clouds, earth-science, ocean-temperature, ocean-winds, oceans
Organization: National Aeronautics and Space Administration
CAMEX-3 ER-2 Millimeter-wave Imaging Radiometer (MIR) V1

The CAMEX-3 ER-2 Millimeter-wave Imaging Radiometer (MIR) dataset is a browse-only dataset containing plots of brightness temperature measurements collected by the Millimeter-wave Imaging Radiometer (MIR) in support of the third field campaign in the Convection And Moisture EXperiment (CAMEX) series, CAMEX-3. This field campaign took place from August to September 1998 based out of Patrick Air Force Base in Florida, with the purpose of studying various aspects of  tropical cyclones in the region. During CAMEX-3, MIR operated onboard the NASA ER-2 high-altitude research aircraft, collecting brightness temperature measurements of water vapor, clouds, precipitation, and other atmospheric features. The MIR browse image files are available from August 8 through September 8, 1998  in GIF format.

Tags: earth-science, infrared-wavelengths, microwave, spectral-engineering
Organization: National Aeronautics and Space Administration
High Mountain Asia Daily 5km Landslide Hazard Indicator V001

This data set projects the daily hazard of rainfall-triggered landslides in the High Mountain Asia region from 2015 through 2100, at 5 km resolution. Projections are provided for two Shared Socioeconomic Pathways (SSPs)—SSP2-4.5 and SSP5 8.5—based on temperature and precipitation projections from a 30-member ensemble climate model.

Landslide hazard is represented by a landslide hazard indicator (LHI), computed with a machine learning model trained on historical temperatures and precipitation and a catalog of documented landslides.

The historical landslides used to train the model are available as a separate record.

Tags: climate-indicators, earth-science, land-surface-agriculture-indicators
Organization: National Aeronautics and Space Administration
eMODIS

eMODIS products respond to specific land remote sensing community need for the benefits of MODIS data without the standard NASA packaging.  eMODIS offers regionally based NDVI products in near-real time and historically using GeoTIFF format, non-sinusoidal map projections, and variable compositing periods.  eMODIS currently (2011) produces NDVI over the continental U.S., Alaska, Central America/Caribbean, Africa and Madagascar, and Central Asia.  Additional geographic and geophysical options are planned based on user requirements.

Tags: agricultural-plant-science, agriculture, biosphere, earth-science, ecological-dynamics, environmental-governance-management, environmental-impacts, forest-science, habitat-conversion-fragmentation, human-dimensions, land-surface, land-use-land-cover, national-geospatial-data-asset, natural-hazards, ngda, terrestrial-ecosystems, vegetation
Organization: National Aeronautics and Space Administration
ATTREX-Aircraft_insitu_TraceGas_Measurements

ATTREX-Aircraft_insitu_TraceGas_Measurements are in-situ trace gas measurements collected onboard the Global Hawk Unihabited Aerial System (UAS) during the Airborne Tropical TRopopause EXperiment (ATTREX) campaign. This collection consists of in-situ trace gas measurements collected by the Diode Laser Hygrometer (DLH), UCATS Gas Chromatograph, Advanced Whole Air Sampler (AWAS), Harvard University Picarro Cavity Ringdown Spectrometer, 2 channel internal path TDL absorption spectrometer, and Dual-channel UV absorption spectrometer for O3 measurements during the 2011 and 2013 deployments over California, and 2014 deployment over Guam. Data collection is complete.
Even though it is typically found in low concentrations, stratospheric water vapor has large impacts on the Earth’s climate and energy budget. Studies have suggested that even relatively small changes in stratospheric humidity may have significant climate impacts and future changes in stratospheric humidity and ozone concentration in response to a changing climate are significant climate feedback. Tropospheric water vapor climate feedback is typically well represented in global models. However, predictions of future changes in stratospheric humidity are highly uncertain due to gaps in our understanding of physical processes occurring in the region of the atmosphere that controls the composition of the stratosphere, the Tropical Tropopause Layer (TTL, ~13-18 km). The ability to predict future changes in stratospheric ozone are also limited due to uncertainties in the chemical composition of the TTL. In order to address these uncertainties, the Airborne Tropical Tropopause Experiment (ATTREX) was completed. Instruments during ATTREX provided measurements to trace the movement of reactive halogen-containing compounds and other important chemical species, the size and shape of cirrus cloud particles, water vapor, and winds in three dimensions through the TTL. Bromine-containing gases were measured to improve understanding of stratospheric ozone. ATTREX consisted of four NASA Global Hawk Uninhabited Aerial System (UAS) campaigns deployed from NASA’s Armstrong Flight Research Center (formally Dryden Flight Research Center). Campaigns were deployed over Edwards, CA, Guam, Hawaii, and Darwin, Australia in Boreal summer, winter, fall, and summer, respectively.

Tags: atmosphere, atmospheric-chemistry, atmospheric-water-vapor, earth-science
Organization: National Aeronautics and Space Administration
SMOS-Based SMAP L2 Radiometer Half-Orbit 9 km EASE-Grid Soil Moisture V001

The Soil Moisture Active Passive (SMAP, launched in 2015) and the Soil Moisture and Ocean Salinity (SMOS, launched in 2009) missions are each L-band satellites that provide brightness temperature and soil moisture estimates and vegetation optical depth approximately every 2-3 days with a spatial resolution of ~40 km. By integrating brightness temperature observations from both satellites, these data products reduce the revisit time to about one day, improving the ability to monitor fast-response processes such as groundwater drainage and recharge, early dry-down after storms, and pre-storm soil moisture conditions for runoff determination. <br>
The Integrated SMAP and SMOS Soil Moisture Data is available in two products: <ul>
<li>SMOS-Based SMAP L2 Radiometer Half-Orbit 9 km EASE-Grid Soil Moisture (NSIDC-0799): This product is generated by processing half-orbit granules (either 6 AM ascending or 6 PM descending) from the pre-processed SMOS product. The L2 product consists solely of SMOS-based data, incorporating information after SMOS brightness temperatures (TBs) at a 40° incidence angle were inter-calibrated and the soil moisture (SM) and vegetation optical depth (VOD) were retrieved using the SMAP Dual Channel Algorithm (DCA). </li>
<li>SMAP/SMOS L3 Radiometer 9 km EASE-Grid Soil Moisture (NSIDC-0800): To generate this product, processing software ingests one day’s worth of granules from both the SMAP SPL2SMP_E product and the SMOS-derived L2 data. The L3 product contains both SMAP and SMOS descending (6:00 AM/PM) and ascending (6:00 PM/AM) data stored in separate arrays. </li>
</ul>

Tags: biosphere, earth-science, land-surface, microwave, soils, spectral-engineering, vegetation
Organization: National Aeronautics and Space Administration
ATLAS/ICESat-2 L1B Converted Telemetry Data V006

This data set (ATL02) contains science-unit-converted time-ordered telemetry data, calibrated for instrument effects, downlinked from the Advanced Topographic Laser Altimeter System (ATLAS) instrument on board the Ice, Cloud and land Elevation Satellite-2 (ICESat-2) observatory. The data are used by the ATLAS/ICESat-2 Science Investigator-led Processing System (SIPS) for system-level, quality control analysis and as source data for ATLAS/ICESat-2 Level-2 products and Precision Orbit Determination (POD) and Precision Pointing Determination (PPD) computations.

Tags: earth-science, lidar, spectral-engineering
Organization: National Aeronautics and Space Administration
GPM GROUND VALIDATION CONICAL SCANNING MILLIMETER-WAVE IMAGING RADIOMETER (COSMIR) IPHEx V1

The GPM Ground Validation Conical Scanning Millimeter-wave Imaging Radiometer (CoSMIR) IPHEx dataset consists of brightness temperatures from 9 channels as measured by the CoSMIR instrument onboard the NASA ER-2 aircraft during the Global Precipitation Mission (GPM) Integrated Precipitation and Hydrology Experiment (IPHEx) field campaign in North Carolina.  The goal of IPHEx was to evaluate the accuracy of satellite precipitation measurements and use the collected data for hydrology models in the region. CoSMIR is a conical and cross-track scanning radiometer with frequencies centered at 50.3, 52.8, 89.0, 165.5, 183.31 ±1, 183.31±3, and 183.31±7 GHz. Data files are available from May 7, 2014 through June 14, 2014 in ASCII format, with browse images available in the postscript format.

Tags: earth-science, microwave, spectral-engineering
Organization: National Aeronautics and Space Administration
Soil Moisture Active Passive (SMAP) L4 Soil Moisture Ancillary Catchment Model Tile Space V001

This ancillary SMAP product contains tile information for the NASA Land Data Assimilation System (LDAS) Catchment model, including center-of-mass latitude/longitude, minimum/maximum latitude/longitude, and the land area fraction of tiles.

Tags: earth-science, sensor-characteristics, spectral-engineering
Organization: National Aeronautics and Space Administration
Distributed Decision-Tree Induction in Peer-to-Peer Systems

This paper offers a scalable and robust distributed algorithm for decision-tree induction in large peer-to-peer (P2P) environments. Computing a decision tree in such large distributed systems using standard centralized algorithms can be very communication-expensive and impractical because of the synchronization requirements. The problem becomes even more challenging in the distributed stream monitoring scenario where the decision tree needs to be updated in response to changes in the data distribution. This paper presents an alternate solution that works in a completely asynchronous manner in distributed environments and offers low communication overhead, a necessity for scalability. It also seamlessly handles changes in data and peer failures. The paper presents extensive experimental results to corroborate the theoretical claims.

Tags: ames, dashlink, nasa
Organization: National Aeronautics and Space Administration
Sounder SIPS: AQUA AIRS IR + MW Level 3 CLIMCAPS : Comprehensive Quality Control Gridded Daily V2 at GES DISC

WARNING: To users of the derived product “co_mmr_midtrop” (carbon monoxide mass mixing ratio to dry air [kg/kg] at ~500 hPa). This variable has a significant bias due to a conversion error: the molecular weight of carbon dioxide (CO2, 44.01 g/mol) was used instead of carbon monoxide (CO, 28.01 g/mol). To correct, simply multiply “co_mmr_midtrop” by 28.01/44.01. Alternatively, derive a profile of mass mixing ratio from scratch using the retrieved column density values (“mol_lay/co_mol_lay”) in the Level 2 files. For further questions or concerns please contact the Sounder SIPS at: sounder.sips@jpl.nasa.gov

The CLIMCAPS (Community Long-term Infrared Microwave Coupled Product System) algorithm is used to analyze data from the AIRS (Atmospheric Infrared Sounder) and AMSU (Advanced Microwave Sounding Unit). The AIRS instrument is a grating spectrometer (R = 1200) aboard the second Earth Observing System (EOS) polar-orbiting platform, EOS Aqua. The AIRS in combination with the AMSU constitutes an innovative atmospheric sounding group of infrared and microwave sensors. The AIRS Standard Retrieval Product consists of retrieved estimates of cloud and surface properties, plus profiles of retrieved temperature, water vapor, ozone, carbon monoxide and methane. The temperature profile vertical resolution is 100 levels total between 1100 mb and 0.1 mb, while moisture profile is reported at atmospheric layers between 1100 mb and 300 mb. The horizontal resolution is 50 km.

The CLIMCAPS algorithm uses an Optimal Estimation methodology and uses an a-priori first guess to start the process. A CLIMCAPS sounding is comprised of a set of parameters that characterizes the full atmospheric state and includes a variety of geophysical parameters derived from the CrIMSS data. These include surface temperature and infrared emissivity; full atmosphere profiles of temperature, water vapor and ozone; infrared effective cloud top characteristics; carbon monoxide, methane, carbon dioxide, sulfur dioxide, nitrous oxide, and nitric acid.

This daily one degree latitude by one degree longitude level-3 product starts with level-2 retrieval products applying the comprehensive quality control (QC) methodology. Comprehensive QC accepts a retrieval if the profile is good to the surface and ensures consistent analysis across all levels and variables.

Tags: air-quality, altitude, atmosphere, atmospheric-chemistry, atmospheric-pressure, atmospheric-radiation, atmospheric-temperature, atmospheric-water-vapor, clouds, earth-science, land-surface, ocean-temperature, oceans, precipitation, surface-radiative-properties, surface-thermal-properties
Organization: National Aeronautics and Space Administration
Removing Spikes While Preserving Data and Noise using Wavelet Filter Banks

Many diagnostic datasets suffer from the adverse
effects of spikes that are embedded in data and noise. For
example, this is true for electrical power system data where
the switches, relays, and inverters are major contributors to
these effects. Spikes are mostly harmful to the analysis of
data in that they throw off real-time detection of abnormal
conditions, and classification of faults. Since noise and
spikes are mixed together and embedded within the data,
removal of the unwanted signals from the data is not always
easy and may result in losing the integrity of the
information carried by the data. Additionally, in some
applications noise and spikes need to be filtered
independently. The proposed algorithm is a multi-resolution
filtering approach based on Haar wavelets that is capable of
removing spikes while incurring insignificant damage to
other data. In particular, noise in the data, which is a useful
indicator that a sensor is healthy and not stuck, can be
preserved using our approach. Presented here is the
theoretical background with some examples from a realistic
testbed.

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