Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “continuous air monitoring”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
NASA NTRS2016

Sampling Indoor Aerosols on the International Space Station

In a spacecraft cabin environment, the size range of indoor aerosols is much larger and they persist longer than on Earth because they are not removed by gravitational settling. A previous aerosol experiment in 1991 documented that over 90 of the mass concentration of particles in the NASA Space Shuttle air were between 10 m and 100 m based on measurements with a multi-stage virtual impactor and a nephelometer (Liu et al. 1991). While the now-retired Space Shuttle had short duration missions (less than two weeks), the International Space Station (ISS) has been continually inhabited by astronauts for over a decade. High concentrations of inhalable particles on ISS are potentially responsible for crew complaints of respiratory and eye irritation and comments about 'dusty' air. Air filtration is the current control strategy for airborne particles on the ISS, and filtration modeling, performed for engineering and design validation of the air revitalization system in ISS, predicted that PM requirements would be met. However, aerosol monitoring has never been performed on the ISS to verify PM levels. A flight experiment is in preparation which will provide data on particulate matter in ISS ambient air. Particles will be collected with a thermophoretic sampler as well as with passive samplers which will extend the particle size range of sampling. Samples will be returned to Earth for chemical and microscopic analyses, providing the first aerosol data for ISS ambient air.

Thermophoretic sampler↗
DOE OSTI2020

Application and Certification of Comparative Vacuum Monitoring Sensors for Structural Health Monitoring of 737 Wing Box Fittings

Multi-site fatigue damage, hidden cracks in hard-to-reach locations, disbonded joints, erosion, impact, and corrosion are among the major flaws encountered in today's extensive fleet of aging aircraft and space vehicles. The use of in-situ sensors for real-time health monitoring of aircraft structures are a viable option to overcome inspection impediments stemming from accessibility limitations, complex geometries, and the location and depth of hidden damage. Reliable, structural health monitoring systems can automatically process data, assess structural condition, and signal the need for human intervention. Prevention of unexpected flaw growth and structural failure can be improved if on-board health monitoring systems are used to continuously assess structural integrity. Such systems are able to detect incipient damage before catastrophic failures occurs. Condition-based maintenance practices could be substituted for the current time-based maintenance approach. Other advantages of on-board distributed sensor systems are that they can eliminate costly, and potentially damaging, disassembly, improve sensitivity by producing optimum placement of sensors and decrease maintenance costs by eliminating more time- consuming manual inspections. This report presents a Sandia Labs-aviation industry effort to move SHM into routine use for aircraft maintenance. This program addressed formal SHM technology validation and certification issues so that the full spectrum of concerns, including design, deployment, performance and certification were appropriately considered. The Airworthiness Assurance NDI Validation Center (AANC) at Sandia Labs, in conjunction with Boeing, Delta Air Lines, Structural Monitoring Systems Ltd., Anodyne Electronics Manufacturing Corp. and the Federal Aviation Administration (FAA) carried out a certification program to formally introduce Comparative Vacuum Monitoring (CVM) as a structural health monitoring solution to a specific aircraft wing box application. Validation tasks were designed to address the SHM equipment, the health monitoring task, the resolution required, the sensor interrogation procedures, the conditions under which the monitoring will occur, the potential inspector population, adoption of CVM into an airline maintenance program and the document revisions necessary to allow for routine use of CVM as an alternate means of performing periodic structural inspects. To carry out the validation process, knowledge of aircraft maintenance practices was coupled with an unbiased, independent evaluation. Sandia Labs designed, implemented, and analyzed the results from a focused and statistically-relevant experimental effort to quantify the reliability of the CVM system applied to the Boeing 737 Wing Box fitting application. All factors that affect SHM sensitivity were included in this program: flaw size, shape, orientation and location relative to the sensors, as well as operational and environmental variables. Statistical methods were applied to performance data to derive Probability of Detection (POD) values for CVM sensors in a manner that agrees with current nondestructive inspection (NDI) validation requirements and also is acceptable to both the aviation industry and regulatory bodies. This report presents the use of several different statistical methods, some of them adapted from NDI performance assessments and some proposed to address the unique nature of damage detection via SHM systems, and discusses how they can converge to produce a confident quantification of SHM performance An important element in developing SHM validation processes is a clear understanding of the regulatory measures needed to adopt SHM solutions along with the knowledge of the structural and maintenance characteristics that may impact the operational performance of an SHM system. This report describes the major elements of an SHM validation approach and differentiates the SHM elements from those found in NDI validation. The activities conducted in this program demonstrated the feasibility of routine SHM usage in general and CVM in particular for the application selected. They also helped establish an optimum OEM-airline-regulator process and determined how to safely adopt SHM solutions. This formal SHM validation will allow aircraft manufacturers and airlines to confidently make informed decisions about the proper utilization of CVM technology. It will also streamline the regulatory actions and formal certification measures needed to assure the safe application of SHM solutions.

42 ENGINEERING↗
DOE OSTI2021

RAMM-TM for detection of gas leakage from canisters containing spent nuclear fuel

Remote Area Modular Monitoring (RAMM) for canister surface temperature measurement (TM), or RAMM-TM, is a novel remote monitoring device for detection of gas leakage based on surface temperature measurements of canisters containing spent nuclear fuel. Here we describe the development of RAMM-TM, as is the demonstration of its performance in detecting canister gas leakage from a small, simulated chloride-induced stress corrosion crack in experiments using a 1/4.5-scale model cask. Both helium and air gas leakage from a canister were detected within hours after the start of the leakage. The change in surface temperatures at the top and bottom of the canister (ΔTBT) during gas leakage (depressurization) triggered automatic alarms, providing a sound basis for early detection of gas leakage from the canister. This methodology would allow consequence management through the implementation of mitigatory actions to continue effective aging management and to reduce risks to public safety, health, and the environment.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS2021

Wilson Corners SWMU 001 2019-2020 Annual Long-Term Monitoring Report Kennedy Space Center, Florida

This report presents a summary of the long-term monitoring (LTM) activities that occurred in 2019 and 2020 at Wilson Corners, Solid Waste Management Unit 001, at the John F. Kennedy Space Center (KSC), Florida. The site is monitored under KSC’s Resource Conservation and Recovery Act Corrective Action Program. Adaptive site management is being utilized through ongoing assessment, design, and interim measures. This approach also meets the requirements of Chapter 62-780, Florida Administrative Code. The goal of LTM at this site is threefold: to determine groundwater flow characteristics, monitor the downgradient concentration trends, and monitor select locations internal to the groundwater plume. Every 5 years, upgradient and side-gradient monitoring wells are sampled to verify delineation. The last time this was performed was in 2015. Sampling of these wells in 2020 was replaced with the direct push technology investigations in October 2020 and April 2021. The activities presented in this report include three field events: (1) December 2019 -groundwater gauging of 38 monitoring wells and sampling of 36 monitoring wells; (2) May 2020 - groundwater sampling of 7 monitoring wells; and (3) December 2020 - groundwater gauging of 49 monitoring wells and sampling of 43 monitoring wells. During the December 2019 and May 2020 events, monitoring wells were sampled using passive diffusion bags and were analyzed for a “full list” of volatile organic compounds (VOCs), including Freon 113. During the December 2020 event, the low flow sampling method was used, and samples were analyzed for a “select list” of VOCs, including Freon 113. The following conclusions can be made based on the 2019 and 2020 LTM results: •In December 2019 and December 2020, groundwater flow for the site was generally to the west with the individual zones only varying by occasional northerly and southerly components. This is generally consistent with historical observations at the site. •The GCTL plume continues to extend both horizontally and vertically beyond our current monitoring well network. •The vertical extent of VOCs was historically generally delineated by monitoring wells screened greater than 48 feet bls. The results from the two vertical extent monitoring wells WILC-MW0078 and WILC-MW0130 that were sampled during the 2019 and 2020 LTM indicate that groundwater VOC concentrations in both wells were greater than the GCTL. •Freon 113 was not detected above GCTLs during the 2019 and 2020 LTM events. Based on groundwater sampling activities performed during this reporting period, including recent DPT groundwater sampling conducted for the implementation of an air sparge system, the following recommendations are provided: •Install 10 new monitoring wells, which will be sampled along with 49 existing monitoring wells, to assist with delineation of the low concentration plume. The wells are listed inTable 4-1, and the proposed locations are presented on Figures4 -1 through 4-5. (Figures 4-1, 4-2, 4-3, and 4-5 also show updated plumes and proposed performance monitoring well locations. This information will be discussed and presented under a separate cover.) •Modify the annual LTM sampling plan as presented inTable 4-1. •Sampling for future events at the site will be conducted using low flow pumping methods. The next annual LTM sampling event is currently planned for December 2021. Please note the 10 new monitoring wells will not be installed before this event but will be installed as part of the upcoming IM construction and will be sampled during baseline sampling, along with the 49 existing monitoring wells. Following this sampling event, it is recommended that the Annual LTM be combined with the performance monitoring under the IM implementation, and LTM be temporarily discontinued. Objectives of the 2021 LTM are to: (i) evaluate groundwater gradient and flow direction by collecting depth to water measurements from LTM wells; (ii) continue monitoring the peripheral VOC trends in the northern, southern, and western portions of the site by monitoring existing wells and installing and monitoring new wells as recommended; and (iii) monitor select internal plume wells.

Jennifer Lynn Joyal↗
DOE OSTI2023

West Valley Demonstration Project (WVDP) (Annual Site Environmental Report (ASER), Calendar Year 2022)

The report, prepared for the U.S. Department of Energy West Valley Demonstration Project office (DOE-WVDP), summarizes the environmental protection program at the WVDP for calendar year (CY) 2022. Monitoring and surveillance of the facilities used by the DOE are conducted to verify protection of public health and safety and the environment. The report is a key component of DOE’s effort to keep the public informed of environmental conditions at the WVDP. The quality assurance protocols applied to the environmental monitoring program ensure the validity and accuracy of the monitoring data. In addition to demonstrating compliance with environmental laws, regulations, and directives, evaluation of data collected in 2022 continued to indicate that WVDP activities pose no threat to public health or safety, or to the environment.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2022

Capillary Water in 2-D Drying-Cracking Soil Sub-Grain Models: Morphology and Kinematics of Evaporation and Haines Jumps

Morphing of capillary water during the drying of a cluster of three wet grains is imaged and measured. The uniqueness of the tests is in the grains being long cylinders to make the system as close to a 2-D one as possible. In this way, the Laplace pressure depends on the only one curvature of the meniscus, which can easily be followed and is continuously image processed. The motion of liquid/gas interface, and its rate, as well as of contact angle and perimeter, are also monitored. The drying water body has been known to undergo two modes of re-morphing: a slow, evaporation rate-controlled one and a fast, inertia-driven instabilities of the interfaces. Two particular forms of dynamic re-morphing are being followed: one, called classically an “air entry,” which is a meniscus jump before its approaching the throat between the top and a bottom grain and another jump of the bottom contact, with a splitting of the meniscus into two between only two of the three grains. Associated dynamic variables, capillary pressure, and surface tension forces developing prior to and in conjunction with the instabilities of the menisci are presented in a companion paper by Hueckel et al..

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS2016

Supply Warehouse#3, SWMU 088 Operations, Maintenance, and Monitoring Report Kennedy Space Center, Florida

This document presents the findings, observations, and results associated with Operations, Maintenance, and Monitoring (OM&M) activities of Corrective Measures Implementation (CMI) activities conducted at Supply Warehouse #3 (SW3) located at John F. Kennedy Space Center (KSC), Florida from October 8, 2015, to September 12, 2016, and performance monitoring results for semi-annual sampling events conducted in March and September 2016. The primary objective of SW3 CMI is to actively decrease concentrations of trichloroethene (TCE) and vinyl chloride (VC) to less than Florida Department of Environmental Protection (FDEP) Natural Attenuation Default Concentrations (NADCs), and the secondary objective is to reduce TCE, cis-1,2-dichloroethene (cDCE), trans-1,2-dichloroethene (tDCE), 1,1-dichloroethene (11DCE), and VC concentrations to less than FDEP Groundwater Cleanup Target Levels (GCTLs). The SW3 facility has been designated Solid Waste Management Unit (SWMU) 088 under KSC's Resource Conservation and Recovery Act (RCRA) Corrective Action Program. Based on the results to date, the SW3 air sparging (AS) system is operating at or below the performance criteria as presented in the 2008 SW3 Corrective Measures Implementation (CMI) Work Plan and 2009 and 2012 CMI Work Plan Addenda. Since the start of AS system operations on December 19, 2012, through the September 2016 groundwater sampling event, TCE concentrations have decreased to less than the GCTL in all wells within the Active Remediation Zone (ARZ), and VC results remain less than NADC but greater than GCTL. Based on these results, team consensus was reached at the October 2016 KSC Remediation Team (KSCRT) meeting to continue AS system operations and semi-annual performance monitoring of volatile organic compounds in March 2017 at ten monitoring wells at select locations, and in September 2017 at four monitoring wells at select locations to reduce VC concentrations to below GCTL. Additionally, surface water samples will be collected at locations SW0001, SW0002, and SW0003 during both the March and September 2017 events. Team consensus was also reached at the October 2017 KSCRT meeting to continue with operation and maintenance (O&M) of the AS system at SW3.

REPORT↗
NASA NTRS2024

Hypergol Maintenance Facility North, SWMU 090, Year 3 Air Sparge System Performance Monitoring Report, Kennedy Space Center, Florida

This Performance Monitoring Report (PMR) presents Year 3 Air Sparge (AS) System operation, maintenance, and monitoring (OM&M) activities and performance monitoring results for the AS Interim Measure (IM) at the Hypergol Maintenance Facility North (HMFN) at Kennedy Space Center (KSC), Florida. HMFN has been designated Solid Waste Management Unit (SWMU) 090 under the KSC Resource Conservation and Recovery Act Corrective Action Program. The timeframe for activities included in this report extends from September 2022 to August 2023. The HMFN AS IM was implemented in 2019-2020 to treat a chlorinated solvent groundwater plume that resulted from historical operations supporting the National Aeronautics and Space Administration (NASA) Space Program. The system includes 213 AS wells, with screen depths ranging from 25 feet to 45 feet below land surface (bls) and treats approximately 1.62 acres of contaminated groundwater. The objective of the AS IM is to actively reduce groundwater concentrations exceeding Florida Department of Environmental Protection Natural Attenuation Default Concentrations (NADCs) (identified as the High Concentration Plume [HCP]) to levels that facilitate transition into a Long-Term Monitoring program. The AS IM targets all of the HCP, except for a source zone area within the HCP where trichloroethene (TCE) concentrations exceed 11,000 micrograms per liter (μg/L) at depths greater than 45 feet bls. This is because site lithology was found to not be conducive to the AS treatment technology at these deeper depths. NASA will re-visit plans for potentially utilizing another remedial technology for residual deeper contamination following completion of the AS IM. OM&M activities and results from Year 3 indicate that the AS system at HMFN is operating as designed and is meeting performance criteria. Groundwater performance monitoring results indicate that following the third year of AS system operation, TCE concentrations in wells across all treated depth intervals have been reduced by an average of more than 99 percent. Overall, the areal extent of the plume showed a reduction following Year 3 of AS operations; however, continued operation of the AS system is required to meet the IM objective.

VOCs↗
NASA NTRSDate not supplied

Evaluating Diurnal Ozone Emissions: A Comparative Analysis of DSCOVR EPIC, PANDORA, and TOLNet Data for Space-Based Monitoring Assessment: A Case Study by ASDC

Stratospheric ozone occurs naturally in the upper atmosphere, forming a protective layer that shields us from the sun's harmful ultraviolet rays. Tropospheric ozone is not emitted directly into the air but is created by chemical reactions between nitrogen oxides (NOx) and volatile organic compounds (VOC). This reaction happens when pollutants emitted by cars, power plants, industrial boilers, refineries, chemical plants, and other sources chemically react in sunlight [1]. Therefore, increased levels of tropospheric ozone indicate the presence of pollutants in the air. While daily anthropogenic activity causes an increase of ground-level ozone, variation of stratospheric ozone changes happens much slower, so that variation of the total ozone column reflects the variation of the tropospheric column due to natural, e.g., wildfires and anthropogenic air pollution. Both total and tropospheric ozone column products are used in this study. The reflectance spectra measured by the Earth Polychromatic Imaging Camera (EPIC) instrument aboard the Deep Space Climate Observatory (DSCOVR) spacecraft are compared with a set of radiative transfer-derived lookup tables for the EPIC filter transmission functions and a wide range of ozone values to retrieve ozone with a maximum resolution of 18 km at the sub-satellite point [2]. EPIC provides total column ozone in level 2 and level 4 products and tropospheric column ozone in level 4 products. Both EPIC Ozone products [2] are available at the Atmospheric Science Data Center (ASDC) at NASA Langley Research Center [3, 4]. Pandora spectrometer instrument measures columnar amounts of trace gases in the atmosphere. These gases (O3, NO2, CH2O) absorb light from the sun at specific wavelengths in the ultraviolet-visible spectrum [5]. Using the theoretical solar spectrum as a reference, Pandora determines trace gas amounts using differential optical absorption spectroscopy (DOAS). Pandora ozone retrievals are available from the Pandonia Global Network [6]. Pandora data from North American major metropolitan areas, New York, NY, Washington DC, Los Angeles, CA, and Mexico City. Tropospheric Ozone Lidar Network (TOLNet) was established in 2012 to provide high spatiotemporal observations of tropospheric ozone to (1) better understand physical processes driving the ozone budget in various meteorological and environmental conditions and (2) validate the tropospheric ozone measurements of space-borne missions [7]. TOLNet data are available at ASDC [8]. While EPIC provides global coverage of ozone retrievals several times daily, temporal resolution may miss some features in daily ozone variations. Ground-based sensors such as Pandora spectrometers and TOLNet lidars provide better temporal resolution while missing continuous spatial coverage. The forthcoming ozone retrieval from the TEMPO mission [9] will provide better spatial and temporal coverage of air quality (including ozone) over North America. This study investigates whether EPIC ozone products can detect diurnal air quality variations and compare ozone temporal development with retrieval by ground-based instruments.

diurnal ozone emissions, DSCOVR EPIC, PANDORA, spa↗
DOE OSTI2024

West Valley Demonstration Project (WVDP) Annual Site Environmental Report (ASER) for Calendar Year 2023

The report, prepared for the U.S. Department of Energy West Valley Demonstration Project office (DOE-WVDP), summarizes the environmental protection program at the WVDP for calendar year (CY) 2023. Monitoring and surveillance of the facilities used by the DOE are conducted to verify protection of public health and safety and the environment. The report is a key component of DOE’s effort to keep the public informed of environmental conditions at the WVDP. The quality assurance protocols applied to the environmental monitoring program ensure the validity and accuracy of the monitoring data. In addition to demonstrating compliance with environmental laws, regulations, and directives, evaluation of data collected in 2023 continued to indicate that WVDP activities pose no threat to public health or safety, or to the environment.

Record of Decision↗
NASA NTRS1974

A standard particle sizer-velocimeter

A standard particle sizer-cum-velocimeter is described, which was designed and built for the purpose of providing a standard source of aerosols of known size-distribution, moving with a known velocity, for the purpose of calibrating the continuous wave (CW) CO2-Laser Doppler Velocimeters at Marshall Space Flight Center. The instrument is designed with the capabilities of: (1) monitoring the size-distribution of particles of diameters larger than 1.0 microns; (2) measuring flow velocities in the range 0.05 - 100.0 cm/sec; (3) photographing particles of diameters above 0.2 microns moving at slow speeds (approximately 0.1 cm/sec); (4) measuring the size-distribution of particles settling in quiet air (or convection velocities of less than 0.15 cm/sec); and (5) use in the laboratory or in the field.

Deepak, A.↗
NASA NTRS1999

Bubble Generation in a Flowing Liquid Medium and Resulting Two-Phase Flow in Microgravity

The present investigation reports a study of bubble generation under reduced gravity conditions, using both a co-flow and a cross-flow configuration. This study may be used in the conceptual design of a space-based thermal management system. Ensuing two-phase flow void fraction can be accurately monitored using a single nozzle gas injection system within a continuous liquid flow conduit, as utilized in the present investigation. Accurate monitoring of void fraction leads to precise control of heat and mass transfer coefficients related to a thermal management system; hence providing an efficient and highly effective means of removing heat aboard spacecraft or space stations. Our experiments are performed in parabolic flight aboard the modified DC-9 Reduced Gravity Research Aircraft at NASA Lewis Research Center, using an air-water system. For the purpose of bubble dispersion in a flowing liquid, we use both a co-flow and a cross-flow configuration. In the co-flow geometry, air is introduced through a nozzle in the same direction with the liquid flow. On the other hand, in the cross-flow configuration, air is injected perpendicular to the direction of water flow, via a nozzle protruding inside the two-phase flow conduit. Three different flow conduit (pipe) diameters are used, namely, 1.27 cm, 1.9 cm and 2.54 cm. Two different ratios of nozzle to pipe diameter (D(sub N))sup * are considered, namely (D(sub N))sup * = 0.1 and 0.2, while superficial liquid velocities are varied from 8 to 70 cm/s depending on flow conduit diameter. It is experimentally observed that by holding all other flow conditions and geometry constant, generated bubbles decrease in size with increase in superficial liquid velocity. Detached bubble diameter is shown to increase with air injection nozzle diameter. Likewise, generated bubbles grow in size with increasing pipe diameter. Along the same lines, it is shown that bubble frequency of formation increases and hence the time to detachment of a forming bubble decreases, as the superficial liquid velocity is in-creased. Furthermore, it is shown that the void fraction of the resulting two-phase flow increases with volumetric gas flow rate Q(sub d), pipe diameter and gas injection nozzle diameter, while they decrease with surrounding liquid flow. The important role played by flowing liquid in detaching bubbles in a reduced gravity environment is thus emphasized. We observe that the void fraction can be accurately controlled by using single nozzle gas injection, rather than by employing multiple port injection, since the later system gives rise to unpredictable coalescence of adjacent bubbles. It is of interest to note that empirical bubble size and corresponding void fraction are somewhat smaller for the co-flow geometry than the cross-flow configuration at similar flow conditions with similar pipe and nozzle diameters. In order to supplement the empirical data, a theoretical model is employed to study single bubble generation in the dynamic (Q(sub d) = 1 - 1000 cu cm/s) and bubbly flow regime within the framework of the co-flow configuration. This theoretical model is based on an overall force balance acting on the bubble during the two stages of generation, namely the expansion and the detachment stage. Two sets of forces, one aiding and the other inhibiting bubble detachment are identified. Under conditions of reduced gravity, gas momentum flux enhances, while the surface tension force at the air injection nozzle tip inhibits bubble detachment. In parallel, liquid drag and inertia can act as both attaching and detaching forces, depending on the relative velocity of the bubble with respect to the surrounding liquid. Predictions of the theoretical model compare well with our experimental results. However, at higher superficial liquid velocities, as the bubble loses its spherical form, empirical bubble size no longer matches the theoretical predictions. In summary, we have developed a combined experimental and theoretical work, which describes the complex process of bubble generation and resulting two-phase flow in a microgravity environment. Results of the present study can be used in a wide range of space-based applications, such as thermal energy and power generation, propulsion, cryogenic storage and long duration life support systems, necessary for programs such as NASA's Human Exploration for the Development of Space (HEDS).

Pais, S. C.↗
NASA NTRS2011

Land and Atmosphere Near-Real-Time Capability for Earth Observing System

The past decade has seen a rapid increase in availability and usage of near-real-time data from satellite sensors. The EOSDIS (Earth Observing System Data and Information System) was not originally designed to provide data with sufficiently low latency to satisfy the requirements for near-real-time users. The EOS (Earth Observing System) instruments aboard the Terra, Aqua and Aura satellites make global measurements daily, which are processed into higher-level 'standard' products within 8-40 hours of observation and then made available to users, primarily earth science researchers. However, applications users, operational agencies, and even researchers desire EOS products in near-real-time to support research and applications, including numerical weather and climate prediction and forecasting, monitoring of natural hazards, ecological/invasive species, agriculture, air quality, disaster relief and homeland security. These users often need data much sooner than routine science processing allows, usually within 3 hours, and are willing to trade science product quality for timely access. While Direct Broadcast provides more timely access to data, it does not provide global coverage. In 2002, a joint initiative between NASA (National Aeronautics and Space Administration), NOAA (National Oceanic and Atmospheric Administration), and the DOD (Department of Defense) was undertaken to provide data from EOS instruments in near-real-time. The NRTPE (Near Real Time Processing Effort) provided products within 3 hours of observation on a best-effort basis. As the popularity of these near-real-time products and applications grew, multiple near-real-time systems began to spring up such as the Rapid Response System. In recognizing the dependence of customers on this data and the need for highly reliable and timely data access, NASA's Earth Science Division sponsored the Earth Science Data and Information System Project (ESDIS)-led development of a new near-real-time system called LANCE (Land, Atmosphere Near-Real-Time Capability for EOS) in 2009. LANCE consists of special processing elements, co-located with selected EOSDIS data centers and processing facilities. A primary goal of LANCE is to bring multiple near-real-time systems under one umbrella, offering commonality in data access, quality control, and latency. LANCE now processes and distributes data from the Moderate Resolution Imaging Spectroradiometer (MODIS), Atmospheric Infrared Sounder (AIRS), Advanced Microwave Scanning Radiometer Earth Observing System (AMSR-E), Microwave Limb Sounder (MLS) and Ozone Monitoring Instrument (OMI) instruments within 3 hours of satellite observation. The Rapid Response System and the Fire Information for Resource Management System (FIRMS) capabilities will be incorporated into LANCE in 2011. LANCE maintains a central website to facilitate easy access to data and user services. LANCE products are extensively tested and compared with science products before being made available to users. Each element also plans to implement redundant network, power and server infrastructure to ensure high availability of data and services. Through the user registration system, users are informed of any data outages and when new products or services will be available for access. Building on a significant investment by NASA in developing science algorithms and products, LANCE creates products that have a demonstrated utility for applications requiring near-real-time data. From lower level data products such as calibrated geolocated radiances to higher-level products such as sea ice extent, snow cover, and cloud cover, users have integrated LANCE data into forecast models and decision support systems. The table above shows the current near-real-time product categories by instrument. The ESDIS Project continues to improve the LANCE system and use the experience gained through practice to seek adjustments to improve the quality and performance of the system. For example, anGC-compliant Web Map Service (WMS) will be added shortly that will allow users to download geo-referenced MODIS images for arbitrary bounding boxes. Further, an OGC-compliant Web Coverage Service (WCS) will be added later this year that will expedite user access to arbitrary data subsets or re-formatted products. AIRS images are now served through WMS and available in multiple formats (PNG, GeoTIFF, KMZ). NASA has established a LANCE User Working Group to steer the development of the system and create a forum for sharing ideas and experiences that are expected to further improve the LANCE capabilities. The LANCE system has proved a success by satisfying the growing needs of the applications and operational communities for land and atmosphere data in near-real-time. NASA's Earth Sciences Division was able to leverage existing science research capabilities to provide the near-real-time community with products and imagery that support monitoring of disasters in a timely manner.

Murphy, Kevin J.↗
NASA NTRS2014

Infrared Spectral Radiance Intercomparisons With Satellite and Aircraft Sensors

Measurement system validation is critical for advanced satellite sounders to reach their full potential of improving observations of the Earth's atmosphere, clouds, and surface for enabling enhancements in weather prediction, climate monitoring capability, and environmental change detection. Experimental field campaigns, focusing on satellite under-flights with well-calibrated FTS sensors aboard high-altitude aircraft, are an essential part of the validation task. Airborne FTS systems can enable an independent, SI-traceable measurement system validation by directly measuring the same level-1 parameters spatially and temporally coincident with the satellite sensor of interest. Continuation of aircraft under-flights for multiple satellites during multiple field campaigns enables long-term monitoring of system performance and inter-satellite cross-validation. The NASA / NPOESS Airborne Sounder Testbed - Interferometer (NAST-I) has been a significant contributor in this area by providing coincident high spectral/spatial resolution observations of infrared spectral radiances along with independently-retrieved geophysical products for comparison with like products from satellite sensors being validated. This presentation gives an overview of benefits achieved using airborne sensors such as NAST-I utilizing examples from recent field campaigns. The methodology implemented is not only beneficial to new sensors such as the Cross-track Infrared Sounder (CrIS) flying aboard the Suomi NPP and future JPSS satellites but also of significant benefit to sensors of longer flight heritage such as the Atmospheric InfraRed Sounder (AIRS) and the Infrared Atmospheric Sounding Interferometer (IASI) on the AQUA and METOP-A platforms, respectively, to ensure data quality continuity important for climate and other applications. Infrared spectral radiance inter-comparisons are discussed with a particular focus on usage of NAST-I data for enabling inter-platform cross-validation.

Larar, Allen M.↗
NASA NTRS2018

Testing Enabling Technologies for Safe UAS Urban Operations

A set of more than 100 flight operations were conducted at NASA Langley Research Center using small UAS (sUAS) to demonstrate, test, and evaluate a set of technologies and an overarching air-ground system concept aimed at enabling safety. The research vehicle was tracked continuously during nominal traversal of planned flight paths while autonomously operating over moderately populated land. For selected flights, off-nominal risks were introduced, including vehicle-to-vehicle (V2V) encounters. Three contingency maneuvers were demonstrated that provide safe responses. These maneuvers made use of an integrated air/ground platform and two on-board autonomous capabilities. Flight data was monitored and recorded with multiple ground systems and was forwarded in real time to a UAS traffic management (UTM) server for airspace coordination and supervision.

Moore, Andrew J.↗
NASA NTRS2004

Global Lightning Activity

Our knowledge of the global distribution of lightning has improved dramatically since the advent of spacebased lightning observations. Of major importance was the 1995 launch of the Optical Transient Detector (OTD), followed in 1997 by the launch of the Lightning Imaging Sensor (LIS). Together, these instruments have generated a continuous eight-year record of global lightning activity. These lightning observations have provided a new global perspective on total lightning activity. For the first time, total lightning activity (cloud-to-ground and intra-cloud) has been observed over large regions with high detection efficiency and accurate geographic location. This has produced new insights into lightning distributions, times of occurrence and variability. It has produced a revised global flash rate estimate (44 flashes per second) and has lead to a new realization of the significance of total lightning activity in severe weather. Accurate flash rate estimates are now available over large areas of the earth (+/- 72 deg. latitude). Ocean-land contrasts as a function of season are clearly reveled, as are orographic effects and seasonal and interannual variability. The space-based observations indicate that air mass thunderstorms, not large storm system dominate global activity. The ability of LIS and OTD to detect total lightning has lead to improved insight into the correlation between lightning and storm development. The relationship between updraft development and lightning activity is now well established and presents an opportunity for providing a new mechanism for remotely monitoring storm development. In this concept, lightning would serve as a surrogate for updraft velocity. It is anticipated that this capability could lead to significantly improved severe weather warning times and reduced false warning rates. This talk will summarize our space-based lightning measurements, will discuss how lightning observations can be used to monitor severe weather, and present a concept for continuous geostationary-based lightning observations.

Christian, Hugh J.↗
DOE OSTI2025

Long-term calibration and validation of stability of the Auger Engineering Radio Array using the diffuse Galactic radio emission

The Auger Engineering Radio Array (AERA) measures radio emission from high-energy extensive air showers. Consisting of 153 autonomous radio-detector stations spread over 17 km^2, it detects radio waves in the frequency range of 30 to 80 MHz. Accurate characterization of the detector response is crucial for proper interpretation of the collected data. Previously, this was achieved through laboratory measurements of the analog chain and simulations and measurements of the antenna's directional response. In this paper, we perform an absolute calibration using the continuously monitored sidereal modulation of the diffuse Galactic radio emission. Calibration is done by comparing the average frequency spectra recorded by the stations with predictions from seven different models of the full radio sky, accounting for the system response, which includes the antenna, filters, and amplifiers. The analysis of the calibration constants over a period of seven years shows no relevant and no significant ageing effect in the AERA antennas. This result confirms the long-term stability of the detector stations and demonstrates the possibility for a radio detector to effectively monitor ageing effects of other detectors operating over extended periods.

Antennas↗
NASA NTRS1983

Capabilities and limitations of existing MST radars: Poker Flat

Designed as a prototype system to continuously monitor the atmosphere up to approximately 100 km, the Poker Flat MST radar began operating in 1979 at a relatively low sensitivity. In almost continuous operation since then, the system is steadily increasing in sensitivity to its ultimate design characteristics. Current and final parameters are listed. The advantages of its modular design, which uses 64 transmitting modules distributed through the 200 mx 200 m antenna array include: easy maintenance, beam switching using very low power switching, air cooled transmitting tubes, lower feedline costs, and no moving parts. Continuous, uninterrupted operation ( 4 years) and less man-made interference because of the remote location) are other assets. Most disadvantages are related to its not-yet-finished status, climate, moose excursions, and operating expenses.

Balsley, B. B.↗