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NASA NTRS2002

The North Alabama Severe Thunderstorm Observations, Research, and Monitoring Network (STORMnet)

The Severe Thunderstorm Observations, Research, and Monitoring network (STORMnet) became operational in 2001 as a test bed to infuse new science and technologies into the severe and hazardous weather forecasting and warning process. STORMnet is collaboration among NASA scientists, National Weather Service (NWS) forecasters, emergency managers and other partners. STORMnet integrates total lightning observations from a ten-station 3-D VHF regional lightning mapping array, the National Lightning Detection Network (NLDN), real-time regional NEXRAD Doppler radar, satellite visible and infrared imagers, and a mobile atmospheric profiling system to characterize storms and their evolution. The storm characteristics and life-cycle trending are accomplished in real-time through the second generation Lightning Imaging Sensor Demonstration and Display (LISDAD II), a distributed processing system with a JAVA-based display application that allows anyone, anywhere to track individual storm histories within the Tennessee Valley region of north Alabama and Tennessee, a region of the southeastern U.S. well known for abundant severe weather.

Goodman, S. J.↗
NASA NTRSDate not supplied

Additional Metadata Guidelines to Improve the Structure and Usability of HDF and NetCDF Files

The Hierarchical Data Format (HDF) and Network Common Data Form (NetCDF) are data file formats created to aid users in the creation or use of scientific data. These file formats are useful for handling large data volumes and hosting extensive metadata as global attributes or variables and are popular with the modeling community. HDF and NetCDF files are largely used with remote sensing data and have been used to support measurements from numerous campaigns, from satellite to aircraft or ground and mobile based measurements. The files from airborne field studies, however, vary greatly in terms of the file structure and the amount and content of metadata. Information relevant to the file that can be useful to the user such as the data producer, location where data was taken, variable descriptions, or information about the instrument might not be included in the file. This metadata might be present in another file in the dataset containing the same data using the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) format. Recently, the Aerosols, Clouds, and their Interactions for Earth System Models (MACIE) group started a grassroots effort to develop a set of requirements for the HDF and NetCDF files for field studies, aiming to make the data products more interoperable and usable. Particularly, these requirements seek to make the files more compliant to Climate and Forecast (CF) metadata conventions and to standardize the file structure and the global and variable attributes. These requirements would help to ensure that HDF and NetCDF files contain adequate metadata to better support their use for research, e.g., the modeling community, and to enhance the usability and interoperability of data for research communities at large. To be presented are the details of the MACIE requirements as well as examples of the implementation of these requirements for merge files and lidar observation data files.

Sean Leavor↗
NASA NTRS2002

Optical Scattering Characterization for the Glennan Microsystems Microscale Particulate Classifier

Small sensors that are tolerant to mechanically and thermally harsh environments present the possibility for in-situ particle characterization in propulsion, industrial, and planetary science applications. Under a continuing grant from the Glennan Microsystems Initiative to the Microgravity Fluids Physics Branch of the NASA-Glenn Research Center, a Microscale Particle Classifier (MiPAC) instrument is being developed. The MiPAC instrument will be capable of determining the size distribution of airborne particles from about 1 nm to 30 micrometers, and will provide partial information as to the concentration, charge state, shape, and structure of the particles, while being an order of magnitude smaller in size and lighter in weight than presently commercially available instruments. The portion of the instrument that will characterize the nm-range particles will employ electrical mobility techniques and is being developed under a separate grant to Prof. David Pui of the University of Minnesota. The portion of the instrument that will characterize the micrometer-size particles such as dirt, pollens, spores, molds, soot, and combustion aerosols will use light scattering techniques. The development of data analysis techniques to be employed in the light scattering portion of the instrument is covered by this grant.

Lock, James A.↗
NASA NTRS2002

The Small Aircraft Transportation System (SATS): Research Collaborations with the NASA Langley Research Center

The aviation industry is an integral part of the world s economy. Travelers have consistently chosen aviation as their mode of transportation as it is reliable, time efficient and safe. The out- dated Hub and Spoke system, coupled with high demand, has led to delays, cancellations and gridlock. NASA is developing innovative solutions to these and other air transportation problems. This research is being conducted through partnerships with federal agencies, industry stakeholders, and academia, specifically the University of Nebraska at Omaha. Each collaborator is pursuing the NASA General Aviation Roadmap through their involvement in the expansion of the Small Aircraft Transportation System (SATS). SATS will utilize technologically advanced small aircraft to transport travelers to and from rural and isolated communities. Additionally, this system will provide a safe alternative to the hub and spoke system, giving more time to more people through high-speed mobility and increased accessibility.

Tarry, Scott E.↗
NASA NTRS2018

Concept Vehicles for VTOL Air Taxi Operations

Concept vehicles are presented for air taxi operations, also known as urban air mobility or on-demand mobility applications. Considering the design-space dimensions of payload (passengers and pilot), range, aircraft type, and propulsion system, three aircraft are designed: a single passenger (250-lb payload), 50-nm range quadrotor with electric propulsion; a six-passenger (1200-lb payload), 4x50 = 200-nm range side-by-side helicopter with hybrid propulsion; and a fifteen-passenger (3000-lb payload), 8x50 = 400-nm range tiltwing with turbo-electric propulsion. These concept vehicles are intended to focus and guide NASA research activities in support of aircraft development for emerging aviation markets, in particular VTOL air taxi operations. Research areas are discussed, illustrated by results from the design of the concept vehicles.

Concept↗
NASA NTRS2020

Investigation of a Tandem Tilt-wing VTOL Aircraft in the NASA Langley 12-Foot Low-Speed Tunnel

The emerging Urban Air Mobility market imposes new design requirements on aircraft, including the ability to have vertical take-off and landing (VTOL) capabilities with the ability to transition into fast and efficient forward flight. Industry has proposed many different vehicle configurations, which have many different challenges. A primary challenge facing many of these concepts is flight through the transition corridor from vertical to horizontal flight and back. In an effort to better understand and help improve vehicle safety in the complex transition corridors, NASA Langley Research Center has proposed to characterize the transition corridor with wind tunnel and flight tests for a variety of unmanned aircraft system sized VTOL configurations. The first vehicle of this series is the Langley Aerodrome 8 (LA-8). LA-8 is a high-risk/high-reward tandem tilt-wing vehicle with distributed electric propulsion and a partially deflected slipstream aircraft. The LA-8 vehicle has gone through a preliminary wind tunnel test in NASA Langley's 12-Foot Low-Speed Wind Tunnel. The results of the aerodynamic data collected, including the longitudinal, lateral, and directional force and moment aerodynamic coefficients, from these tests during different phases of flight are presented.

VTOL↗
NASA NTRSDate not supplied

Airspace Performance Observations of Scalable Autonomous Operations in a High Density Vertiplex Simulation

The National Aeronautics and Space Administration’s (NASA’s) High Density Vertiplex (HDV) sub- project aims to develop and demonstrate progressive automation technologies that contribute to the Advanced Air Mobility (AAM) concept. Using Human-and-Hardware-In-The- Loop (HHITL) techniques, HDV demonstrates initial vertiport automation services at vertiports with increased air traffic volume in both simulated and live test environments. In 2023, the Scalable Autonomous Operations (SAO) simulation was conducted in which prototype vertiport, airspace, and ground control station technologies were assessed on technical performance. During the SAO simulation, an observational study captured an initial impression of the HDV airspace performance, potential disruptions to the airspace, and highlighted some capability and procedural gaps. Observations took place in two parts. In the first part, five scenario use cases (Nominal, Missed Approach, Speed Change, Divert, and Multi- Aircraft Divert) were conducted with three human operator roles (Vertiport Manager, Fleet Manager, and Ground Control Station Operator). Researchers collected metrics on throughput, closest point of approach, and airborne delay. In the second part of the study, the Missed Approach scenario was observed under three traffic density levels (20, 40, and 60 operations per hour) to challenge the automation to correctly identify slots in the vertiport arrival schedule. The results showed that the automation successfully found a slot for the Missed Approach vehicle in the 20 operations per hour condition, after some delay it found one in the 40 condition, and it did not find one in the 60 condition. The observations of technical and human performance throughout the five scenario use cases and the Missed Approach case study indicated that for HDV to increase traffic density and maintain or increase throughput, airspace monitoring services should be able to detect and resolve conflicts between aircraft. Furthermore, the roles and responsibilities of human operators need additional definition when it comes to responding to vehicle conflicts.

advanced air mobility↗
NASA NTRSDate not supplied

Airspace Performance Observations of Scalable Autonomous Operations in a High Density Vertiplex Simulation

The National Aeronautics and Space Administration’s (NASA’s) High Density Vertiplex (HDV) subproject aims to develop and demonstrate progressive automation technologies that contribute to the Advanced Air Mobility (AAM) concept. Using Human-and-Hardware-In-TheLoop (HHITL) techniques, HDV demonstrates initial vertiport automation services at vertiports with increased air traffic volume in both simulated and live test environments. In 2023, the Scalable Autonomous Operations (SAO) simulation was conducted in which prototype vertiport, airspace, and ground control station technologies were assessed on technical performance. During the SAO simulation, an observational study captured an initial impression of the HDV airspace performance, potential disruptions to the airspace, and highlighted some capability and procedural gaps. Observations took place in two parts. In the first part, five scenario use cases (Nominal, Missed Approach, Speed Change, Divert, and MultiAircraft Divert) were conducted with three human operator roles (Vertiport Manager, Fleet Manager, and Ground Control Station Operator). Researchers collected metrics on throughput, closest point of approach, and airborne delay. In the second part of the study, the Missed Approach scenario was observed under three traffic density levels (20, 40, and 60 operations per hour) to challenge the automation to correctly identify slots in the vertiport arrival schedule. The results showed that the automation successfully found a slot for the Missed Approach vehicle in the 20 operations per hour condition, after some delay it found one in the 40 condition, and it did not find one in the 60 condition. The observations of technical and human performance throughout the five scenario use cases and the Missed Approach case study indicated that for HDV to increase traffic density and maintain or increase throughput, airspace monitoring services should be able to detect and resolve conflicts between aircraft. Furthermore, the roles and responsibilities of human operators need additional definition when it comes to responding to vehicle conflicts.

Advanced Air Mobility↗
NASA NTRS2004

Lithium Polymer Electrolytes and Solid State NMR

Research is being done at the Glenn Research Center (GRC) developing new kinds of batteries that do not depend on a solution. Currently, batteries use liquid electrolytes containing lithium. Problems with the liquid electrolyte are (1) solvents used can leak out of the battery, so larger, more restrictive, packages have to be made, inhibiting the diversity of application and decreasing the power density; (2) the liquid is incompatible with the lithium metal anode, so alternative, less efficient, anodes are required. The Materials Department at GRC has been working to synthesize polymer electrolytes that can replace the liquid electrolytes. The advantages are that polymer electrolytes do not have the potential to leak so they can be used for a variety of tasks, small or large, including in the space rover or in space suits. The polymers generated by Dr. Mary Ann Meador's group are in the form of rod -coil structures. The rod aspect gives the polymer structural integrity, while the coil makes it flexible. Lithium ions are used in these polymers because of their high mobility. The coils have repeating units of oxygen which stabilize the positive lithium by donating electron density. This aids in the movement of the lithium within the polymer, which contributes to higher conductivity. In addition to conductivity testing, these polymers are characterized using DSC, TGA, FTIR, and solid state NMR. Solid state NMR is used in classifying materials that are not soluble in solvents, such as polymers. The NMR spins the sample at a magic angle (54.7') allowing the significant peaks to emerge. Although solid state NMR is a helpful technique in determining bonding, the process of preparing the sample and tuning it properly are intricate jobs that require patience; especially since each run takes about six hours. The NMR allows for the advancement of polymer synthesis by showing if the expected results were achieved. Using the NMR, in addition to looking at polymers, allows for participation on a variety of other projects, including aero-gels and carbon graphite mat en als. The goals of the polymer electrolyte research are to improve the physical properties of the polymers. This includes improving conductivity, durability, and expanding the temperature range over which it is effective. Currently, good conductivity is only present at high temperatures. My goals are to experiment with different arrangements of rods and coils to achieve these desirable properties. Some of my experiments include changing the number of repeat units in the polymer, the size of the diamines, and the types of coil. Analysis of these new polymers indicates improvement in some properties, such as lower glass transition temperature; however, they are not as flexible as desired. With further research we hope to produce polymers that encompass all of these properties to a high degree.

Berkeley, Emily R.↗
NASA NTRS1986

A survey of the state-of-the-art and focused research in range systems, task 1

This final report presents the latest research activity in voice compression. We have designed a non-real time simulation system that is implemented around the IBM-PC where the IBM-PC is used as a speech work station for data acquisition and analysis of voice samples. A real-time implementation is also proposed. This real-time Voice Compression Board (VCB) is built around the Texas Instruments TMS-3220. The voice compression algorithm investigated here was described in an earlier report titled, Low Cost Voice Compression for Mobile Digital Radios, by the author. We will assume the reader is familiar with the voice compression algorithm discussed in this report. The VCB compresses speech waveforms at data rates ranging from 4.8 K bps to 16 K bps. This board interfaces to the IBM-PC 8-bit bus, and plugs into a single expansion slot on the mother board.

Omura, J. K.↗
NASA NTRS2017

Secure Network-Centric Aviation Communication (SNAC)

The existing National Airspace System (NAS) communications capabilities are largely unsecured, are not designed for efficient use of spectrum and collectively are not capable of servicing the future needs of the NAS with the inclusion of new operators in Unmanned Aviation Systems (UAS) or On Demand Mobility (ODM). SNAC will provide a ubiquitous secure, network-based communications architecture that will provide new service capabilities and allow for the migration of current communications to SNAC over time. The necessary change in communication technologies to digital domains will allow for the adoption of security mechanisms, sharing of link technologies, large increase in spectrum utilization, new forms of resilience and redundancy and the possibly of spectrum reuse. SNAC consists of a long term open architectural approach with increasingly capable designs used to steer research and development and enable operating capabilities that run in parallel with current NAS systems.

Communications↗
NASA NTRS1978

Lidar remote sensing of tropospheric pollutants and trace gases - Programs of NASA Langley Research Center

NASA Langley Research Center is engaged in a number of in-house and contracted programs to develop, evaluate, and apply lidar techniques to remote measurements of pollutant gases, trace molecules, and aerosols. The differential absorption lidar (DIAL) research programs include the development and evaluation of a UV DIAL system for remote measurements of SO2 and O3 concentrations and aerosol dispersion in urban and power-plant stack plumes, a near-IR DIAL system for vertical measurements of water vapor concentrations, and a high-power tunable IR DIAL system which will measure the concentration of gas species that have absorption features in the 1.4- to 4.4-micron wavelength range. The lidar programs which deal with aerosol measurements include the evaluation of a mobile ruby lidar system for use in plume dispersion model verification and the development of a high-spectral-resolution lidar system for measurement of aerosol extinction and backscattering coefficients. System characteristics and measurement sensitivities are discussed, and comparisons are made between simulations and experimental results.

Browell, E. V.↗
NASA NTRS2011

L-Band System Engineering - Concepts of Use, Systems Performance Requirements, and Architecture

This document is being provided as part of ITT s NASA Glenn Research Center Aerospace Communication Systems Technical Support (ACSTS) contract NNC05CA85C, Task 7: New ATM Requirements-Future Communications, C-band and L-band Communications Standard Development. Task 7 was motivated by the five year technology assessment performed for the Federal Aviation Administration (FAA) under the joint FAA-EUROCONTROL cooperative research Action Plan (AP-17), also known as the Future Communications Study (FCS). It was based on direction provided by the FAA project-level agreement (PLA FY09_G1M.02-02v1) for "New ATM Requirements-Future Communications." Task 7 was separated into two distinct subtasks, each aligned with specific work elements and deliverable items. Subtask 7-1 addressed C-band airport surface data communications standards development, systems engineering, test bed development, and tests/demonstrations to establish operational capability for what is now referred to as the Aeronautical Mobile Airport Communications System (AeroMACS). Subtask 7-2, which is the subject of this report, focused on preliminary systems engineering and support of joint FAA/EUROCONTROL development and evaluation of a future L-band (960 to 1164 MHz) air/ground (A/G) communication system known as the L-band digital aeronautical communications system (L-DACS), which was defined during the FCS. The proposed L-DACS will be capable of providing ATM services in continental airspace in the 2020+ timeframe. Subtask 7-2 was performed in two phases. Phase I featured development of Concepts of Use, high level functional analyses, performance of initial L-band system safety and security risk assessments, and development of high level requirements and architectures. It also included the aforementioned support of joint L-DACS development and evaluation, including inputs to L-DACS design specifications. Phase II provided a refinement of the systems engineering activities performed during Phase I, along with continued joint FAA/EUROCONTROL L-DACS development and evaluation support.

Henriksen, Stephen↗
NASA NTRS2023

m:N Working Group Annual Status Report

This document serves as an annual report of m:N Unmanned Aircraft Systems (UAS) subgroup activities, addressed challenges, and roadmaps for the future. The subgroups consist of small Unmanned Aircraft Systems (sUAS), Large UAS, High Altitude Platform Systems (HAPS), and Urban Air Mobility (UAM). Also included in this report are participant lists for each subgroup (Appendix B) and future roadmap and outreach plans.The subgroups meet in a virtual format multiple times throughout the year. Twice a year, participants from all the subgroups come together as part of the m:N working group to brief each other in person on progress, challenges, and path forward ideas for successful incorporation of UAS into the airspace. Recent m:N in person meetings include: - November 29-30, 2022 at the NASA Ames Research Center in Mountain View, CA - May 9 & 11, 2023 at AUVSI’s Xponential conference in Denver, CO - The next in person working group meeting is planned for November 28-30, 2023 at NASA Langley in Hampton, Virginia The m:N UAS working group is run by Jay Shively (Adaptive Aerospace) and Andy Thurling (Thurling Aero Consulting) and is comprised of members from government, industry, and academia in an effort to identify and reduce barriers to m:N operations. This effort also includes identifying requirements, use cases, and metrics to support organizations and groups including the Federal Aviation Administration (FAA) and Radio Technical Commission for Aeronautics (RTCA’s) SC-228 Detect and Avoid committee.

multi-vehicle↗
NASA NTRS1997

Interaction and Aggregation of Colloidal Biological Particles and Droplets in Electrically-Driven Flows

The primary objective of this research was to develop a fundamental understanding of aggregation and coalescence processes during electrically-driven migration of cells, particles and droplets. The process by which charged cells, particles, molecules, or drops migrate in a weak electric field is known as electrophoresis. If the migrating species have different charges or surface potentials, they will migrate at different speeds and thus may collide and aggregate or coalesce. Aggregation and coalescence are undesirable, if the goal is to separate the different species on the basis of their different electrophoretic mobilities.

Davis, Robert H.↗
NASA NTRS2001

Extending the Capability of Mars Umbilical Technology Demonstrator

The objective of this project is to expand the capabilities of for the Mars Umbilical Technology Demonstrator (MUTD). The MUTD shall provide electrical power and fiber optic data cable connections between two simulated mars vehicles, 1000 in apart. ne wheeled mobile robot Omnibot is used to provide the mobile base for the system. The mate-to umbilical plate is mounted on a Cartesian robot, which is installed on the Omnibot mobile base. It is desirable to provide the operator controlling the Omnibot, the distance and direction to the target. In this report, an approach for finding the position and orientation of the mobile robot using inertial sensors and beacons is investigated. First phase of the project considered the Omnibot being on the flat surface. To deal with the uneven Mars environment, the orientation as well as position needs to be controlled. During local positioning, the information received from four ultrasonic sensors installed at the four corner of the mate-mi plate is used to identify the position of mate-to plate and mate the umbilical plates autonomously. The work proposed is the continuation of the principal investigator research effort as a participant in the 1999 NASA/ASEE Summer Faculty Fellowship Program.

Houshangi, Nasser↗
NASA NTRS2002

A Method of Separation Assurance for Instrument Flight Procedures at Non-Radar Airports

A method to provide automated air traffic separation assurance services during approach to or departure from a non-radar, non-towered airport environment is described. The method is constrained by provision of these services without radical changes or ambitious investments in current ground-based technologies. The proposed procedures are designed to grant access to a large number of airfields that currently have no or very limited access under Instrument Flight Rules (IFR), thus increasing mobility with minimal infrastructure investment. This paper primarily addresses a low-cost option for airport and instrument approach infrastructure, but is designed to be an architecture from which a more efficient, albeit more complex, system may be developed. A functional description of the capabilities in the current NAS infrastructure is provided. Automated terminal operations and procedures are introduced. Rules of engagement and the operations are defined. Results of preliminary simulation testing are presented. Finally, application of the method to more terminal-like operations, and major research areas, including necessary piloted studies, are discussed.

Conway, Sheila R.↗
NASA NTRS2011

C-Band Airport Surface Communications System Standards Development. Phase II Final Report. Volume 1: Concepts of Use, Initial System Requirements, Architecture, and AeroMACS Design Considerations

This report is provided as part of ITT s NASA Glenn Research Center Aerospace Communication Systems Technical Support (ACSTS) contract NNC05CA85C, Task 7: New ATM Requirements-Future Communications, C-Band and L-Band Communications Standard Development and was based on direction provided by FAA project-level agreements for New ATM Requirements-Future Communications. Task 7 included two subtasks. Subtask 7-1 addressed C-band (5091- to 5150-MHz) airport surface data communications standards development, systems engineering, test bed and prototype development, and tests and demonstrations to establish operational capability for the Aeronautical Mobile Airport Communications System (AeroMACS). Subtask 7-2 focused on systems engineering and development support of the L-band digital aeronautical communications system (L-DACS). Subtask 7-1 consisted of two phases. Phase I included development of AeroMACS concepts of use, requirements, architecture, and initial high-level safety risk assessment. Phase II builds on Phase I results and is presented in two volumes. Volume I (this document) is devoted to concepts of use, system requirements, and architecture, including AeroMACS design considerations. Volume II describes an AeroMACS prototype evaluation and presents final AeroMACS recommendations. This report also describes airport categorization and channelization methodologies. The purposes of the airport categorization task were (1) to facilitate initial AeroMACS architecture designs and enable budgetary projections by creating a set of airport categories based on common airport characteristics and design objectives, and (2) to offer high-level guidance to potential AeroMACS technology and policy development sponsors and service providers. A channelization plan methodology was developed because a common global methodology is needed to assure seamless interoperability among diverse AeroMACS services potentially supplied by multiple service providers.

Hall, Edward↗