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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.

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All sourcesNASA NTRSDOE OSTI
NASA NTRS2015

KSC 50-MHz Doppler Radar Wind Profiler (DRWP) Operational Acceptance Test (OAT) Report

This report documents analysis results of the Kennedy Space Center updated 50-MHz Doppler Radar Wind Profiler (DRWP) Operational Acceptance Test (OAT). This test was designed to demonstrate that the new DRWP operates in a similar manner to the previous DRWP for use as a situational awareness asset for mission operations at the Eastern Range to identify rapid changes in the wind environment that weather balloons cannot depict. Data examination and two analyses showed that the updated DRWP meets the specifications in the OAT test plan and performs at least as well as the previous DRWP. Data examination verified that the DRWP provides complete profiles every five minutes from 1.8-19.5 km in vertical increments of 150 m. Analysis of 5,426 wind component reports from 49 concurrent DRWP and balloon profiles presented root mean square (RMS) wind component differences around 2.0 m/s. The DRWP's effective vertical resolution (EVR) was found to be 300 m for both the westerly and southerly wind component, which the best EVR possible given the DRWP's vertical sampling interval. A third analysis quantified the sensitivity to rejecting data that do not have adequate signal by assessing the number of first-guess propagations at each altitude. This report documents the data, quality control procedures, methodology, and results of each analysis. It also shows that analysis of the updated DRWP produced results that were at least as good as the previous DRWP with proper rationale. The report recommends acceptance of the updated DRWP for situational awareness usage as per the OAT's intent.

Profiler↗
NASA NTRS2016

Results of the NASA Kennedy Space Center 50-MHz Doppler Radar Wind Profiler Operational Acceptance Test

This paper presents results of the new Kennedy Space Center (KSC) 50-MHz Doppler Radar Wind Profiler (DRWP) Operational Acceptance Test (OAT). The goal of the OAT was to verify the data quality of the new DRWP against the performance of the previous DRWP in order to use wind data derived by the new DRWP for space launch vehicle operations support at the Eastern Range. The previous DRWP was used as a situational awareness asset for mission operations to identify rapid changes in the wind environment that weather balloons cannot depict. The Marshall Space Flight Center's Natural Environments Branch assessed data from the new DRWP collected during Jan-Feb 2015 against a specified set of test criteria. Data examination verified that the DRWP provides complete profiles every five minutes from 1.8-19.5 km in vertical increments of 150 m. Analysis of 49 concurrent DRWP and balloon profiles presented root mean square wind component differences around 2.0 m/s. Evaluation of the DRWP's coherence between five-minute wind pairs found the effective vertical resolution to be Nyquist-limited at 300 m for both wind components. In addition, the sensitivity to rejecting data that do not have adequate signal was quantified. This paper documents the data, quality control procedures, methodology, and results of each analysis.

Barbre', Robert E., Jr.↗
NASA NTRS2019

A Comparison of Boundary Layer Wind Profilers for Use with Space Launch Vehicles

The United States Air Force (USAF) operates two space launch ranges, the Eastern Range (ER) and the Western Range (WR). The ER is primarily located at the Cape Canaveral Air Force Station (CCAFS) and the WR is located at the Vandenberg Air Force Base (VAFB). Multiple systems are used to measure the atmosphere at both ranges, including a suite of 915-Mhz (megahertz) Doppler Radar Wind Profilers (DRWP). The 915-MHz DRWPs are used to measure winds in the lowest few kilometers of the atmosphere, primarily in the boundary layer. Boundary layer winds are important during launch, and observations of such can be used as input to toxic dispersion and low-level abort trajectory models. However, these 915-MHz systems are nearing the end of their service life and need to be replaced by systems with similar, or greater, capabilities. The USAF funded evaluations of two systems: a 449-MHz DRWP and a Lidar. Both systems were stationed at each range for separate periods of approximately three months from November 2017 through May 2018. The USAF also funded NASA’s Marshall Space Flight Center (MSFC) Natural Environments Branch (NE) to evaluate wind output from the two systems. MSFC NE conducted analysis to demonstrate the system’s wind accuracy relative to measurements from the Automated Meteorological Profiling System (AMPS) (Divers et al., 2000), data availability, and Effective Vertical Resolution (EVR).

Orcutt, John M.↗
NASA NTRS2019

High-Resolution, Lightweight, and Low-cost X-Ray Optics for the Lynx Observatory

We describe an approach to build an x-ray mirror assembly that can meet Lynx’s requirements of high-angular resolution, large effective area, light weight, short production schedule, and low-production cost. Adopting a modular hierarchy, the assembly is composed of 37,492 mirror segments, each of which measures ∼100 mm × 100 mm × 0.5 mm. These segments are integrated into 611 modules, which are individually tested and qualified to meet both science performance and spaceflight environment requirements before they in turn are integrated into 12 metashells. The 12 metashells are then integrated to form the mirror assembly. This approach combines the latest precision polishing technology and the monocrystalline silicon material to fabricate the thin and lightweight mirror segments. Because of the use of commercially available equipment and material and because of its highly modular and hierarchical building-up process, this approach is highly amenable to automation and mass production to maximize production throughput and to minimize production schedule and cost. As of fall 2018, the basic elements of this approach, including substrate fabrication, coating, alignment, and bonding, have been validated by the successful building and testing of single-pair mirror modules. In the next few years, the many steps of the approach will be refined and perfected by repeatedly building and testing mirror modules containing progressively more mirror segments to fully meet science performance, spaceflight environments, as well as programmatic requirements of the Lynx mission and other proposed missions, such as AXIS.

Zhang, William W.↗
NASA NTRS2020

The Silicon Meta-shell X-ray Mirror Technology Development Roadmap for the Lynx Mission

This document presents a roadmap for advancing the silicon meta-shell optics (SMO). It describes an overall strategy and key technical elements to be developed to meet the four-fold Lynx requirements: (1) angular resolution, (2) effective area, (3) mass, and (4) production schedule and cost. It also describes the building and testing of an engineering unit whose successful completion will retire all risks, technical, logistical, schedule, and cost, associated with building and delivering a mirror assembly for the Lynx mission. All of this work, designed to advance this technology to TRL 6, will be completed by Preliminary Design Review (PDR) to ensure that the flight mirror assembly production process will be but a repetition of a set of well-defined and mature steps, leading to on-time and on-budget delivery of a mirror assembly for the Lynx mission.

Zhang, William W.↗
NASA NTRS2021

Performance Assessment of the Eastern Range Titusville-Cocoa 915-MHz Doppler Radar Wind Profiler

The United States Space Force (USSF) is responsible for space vehicle launches at its Eastern Range (ER), which includes the Cape Canaveral Space Force Station (CCSFS). Multiple systems are used to measure the atmosphere at the ER, including suites of Doppler Radar Wind Profilers (DRWPs)that operate at 915MHz and measure winds within the lowest few kilometers of the atmosphere. Observations of boundary layer winds can be used for multiple applications, including serving as input to toxic dispersion models and characterizing winds for low-level aborts. The USSF upgraded the Titusville-Cocoa(TICO)DRWP, which collected data during the spring and summer of 2020. The USSF also requested NASA’s Marshall Space Flight Center (MSFC) Natural Environments Branch (NE) to evaluate wind output from this DRWP system. This report describes the system and the analyses that MSFC NE conducted to demonstrate the system’s wind accuracy relative to balloons from the Automated Meteorological Profiling System (AMPS), data availability, and effective vertical resolution (EVR).

B. J. Barbre↗
NASA NTRS2021

Performance Assessment of the Eastern Range False Cape 915-MHz Doppler Radar Wind Profiler

The United States Space Force (USSF) is responsible for space vehicle launches at its Eastern Range (ER), which includes the Cape Canaveral Space Force Station (CCSFS). Multiple systems are used to measure the atmosphere at the ER, including suites of Doppler Radar Wind Profilers (DRWPs) operating at 915 MHz that measure winds within the lowest few kilometers of the atmosphere. Observations of boundary layer winds can be used for multiple applications, including serving as input to toxic dispersion models and characterizing winds for low-level aborts. The USSF upgraded the False Cape DRWP, which collected data during the autumn of 2020. The USSF also requested NASA’s Marshall Space Flight Center (MSFC) Natural Environments Branch (NE) to evaluate wind output from this DRWP system. This report describes the system and the analyses that MSFC NE conducted to demonstrate the system’s wind accuracy relative to balloons from the Automated Meteorological Profiling System (AMPS), data availability, and effective vertical resolution (EVR).

BJ Barbre↗
NASA NTRS2021

Performance Assessment of the Eastern Range Mosquito Lagoon 915-MHz Doppler Radar Wind Profiler

Please find enclosed the performance assessment for the Mosquito Lagoon 915-MHz Doppler Radar Wind Profiler (DRWP). This assessment was conducted following the installation of the new DRWP systems at the Eastern Range. DRWP profiles were compared to Automated Meteorological Profiling System balloons launched from Cape Canaveral Space Force Station. Launching balloons from the DRWP site was discussed, but was determined to be unfeasible. Therefore, these results include errors due to the spatial separation of winds. Mean wind component deltas generally ranged between -1.4-2.0 m/s between the balloons and DRWP systems. Data availability at discrete altitudes ranged from 7% to 98% with the least amount of available profiles being in the upper altitude ranges between 4000 m and 5000 m as well as below 300 m. The effective vertical resolution was not able to be estimated in this study, likely due to the relatively small dataset. The results from this analysis were requested by the United States Space Force for use of the acceptance of the DRWP system and for internal EV44 reference.

meteorology↗
NASA NTRS2021

Performance Assessment of a Western Range 915-MHz Doppler Radar Wind Profiler

Please find enclosed the performance assessment for a Western Range 915-MHz Doppler Radar Wind Profiler (DRWP). This assessment was conducted following the installation of the new DRWP systems at the Western and Eastern Ranges. DRWP profiles were compared to Automated Meteorological Profiling System balloons launched from Vandenberg Space Force Base. Balloon data was collected from both normal synoptic and launch operations as well as some releases at the DRWP site. These results will include errors due to the spatial separation of winds. Root Mean Square wind speed deltas between the balloons and DRWP system mainly ranged between 1.0 and 2.3 m/s. Mean wind direction deltas mainly ranged between 10 and 28 degrees for wind speeds greater than or equal to 4 m/s. Data availability at discrete altitudes ranged from 20% to 94% with the least amount of available profiles being in the lower altitude ranges between 100 m and 500 m. The effective vertical resolution was determined to be approximately 250 m. The results from this analysis were requested by the United States Space Force for use of the acceptance of the DRWP system and for internal EV44 reference.

B J Barbre↗
NASA NTRSDate not supplied

MaGIXS 2: Preparations for the Second Flight of the Marshall Grazing Incidence X-ray Spectrometer

Overview MaGIXS is a slitless soft X-ray (SXR) imaging spectrometer designed to observe solar active regions. - The instrument produces spatially resolved SXR spectra, known as “overlappograms.” (Athiray et al. 2019 & Champey et al., 2022) The first sounding rocket flight of the Marshall Grazing Incidence X-ray Spectrometer occurred on July 30, 2021 from the White Sands Missile Range, New Mexico. - Spectrally pure images of X-ray bright points were obtained through the inversion of overlappograms, e.g. Fig. 3 (Savage et al., 2022). MaGIXS 2 is a simplified version of the original design, less the spectrometer mirror pair. - Eliminating the spectrometer mirror pair improves spatial resolution, increases effective area and the field of view (Table 1). No field stop in this design, data will be an overlappogram with the same spatial and spectral plate scale.

x-ray spectrometer, x-ray optics, solar corona, so↗
NASA NTRSDate not supplied

The Effect of Trailing Edge Grid Resolution in Large-Eddy Simulations

Ceramic Matrix Composite (CMC) with environmental barrier coating can tolerate significantly higher temperatures compared with the conventional metal alloy blades and thus can help achieve higher thermal efficiency in gas turbine engines. Due to the complex fabrication process of CMC blades, larger blade trailing edge thicknesses and larger leading-edge radii of curvature are expected. These features significantly alter aerodynamic performance especially near the trailing edge and thus the loss profile. In previous studies, the authors used the large eddy simulation (LES) as well as the Reynolds Averaged Navier-Stokes (RANS) coupled with an intermittency function-based transition model to simulate an aerodynamics performance of three different CMC blades and compared the predictions against the data acquired at NASA Glenn Transonic Turbine Blade Cascade Rig. Although we were able to successfully predict different characteristics of aerodynamic performance among three different blades (e.g., pressure loading and integrated losses), LES consistently predicted a small recirculation bubble at the end of the suction side. This was not inconsistent with the physics of the flow, but the pressure loading, locally, near the trailing edge, and as a result, the measured wake profiles did not match the experimental data. To delve further into these issues, a new LES grid with a much finer mesh near the trailing edge was generated where the spanwise extent of the grid was increased by 50%. An LES simulation for the CMC blade with the largest trailing edge thicknesses at the high-freestream turbulence (Tu=13%) condition showed that using such a mesh is necessary for LES to accurately capture the transition phenomena on the suction side. The resulting total pressure coefficient profile and the shift of the wake profile were greatly improved.

CMC↗
NASA NTRS2022

How Well do Multisatellite Products Capture the Space-Time Dynamics of Precipitation? Part II: Building an Error Model Through Spectral System Identification

Satellite precipitation products, as all quantitative estimates, come with some inherent degree of uncertainty. To associate a quantitative value of the uncertainty to each individual estimate, error modeling is necessary. Most of the error models proposed so far compute the uncertainty as a function of precipitation intensity only, and only at one specific spatio-temporal scale. We propose a spectral error model which accounts for the neighboring space-time dynamics of precipitation into the uncertainty quantification. Systematic distortions of the precipitation signal and random errors are characterized distinctively in every frequency-wavenumber band in the Fourier domain, to accurately characterize error across scales. The systematic distortions are represented as a deterministic space-time linear filtering term. The random errors are represented as a non-stationary additive noise. The spectral error model is applied to the IMERG multi satellite precipitation product and its parameters are estimated empirically through a system identification approach using the GV-MRMS gauge-radar measurements as reference (“truth”) over the eastern United States. The filtering term is found to be essentially low-pass. While traditional error models attribute most of the error variance to random errors, it is found here that the systematic filtering term explains 48% of the error variance at the native resolution of IMERG. This fact confirms that, at high resolution, filtering effects in satellite precipitation products cannot be ignored, and that the error cannot be represented as a purely random additive or multiplicative term. An important consequence is that precipitation estimates derived from totally different sources shall not be expected to automatically have statistically independent errors.

Precipitation↗
NASA NTRSDate not supplied

The Effect of Trailing Edge Grid Resolution in Large-Eddy Simulations

Ceramic Matrix Composite (CMC) with environmental barrier coating can tolerate significantly higher temperatures compared with the conventional metal alloy blades and thus can help achieve higher thermal efficiency in gas turbine engines. Due to the complex fabrication process of CMC blades, larger blade trailing edge thicknesses and larger leading-edge radii of curvature are expected. These features significantly alter aerodynamic performance especially near the trailing edge and thus the loss profile. In previous studies, the authors used the large eddy simulation (LES) as well as the Reynolds Averaged Navier-Stokes (RANS) coupled with an intermittency function-based transition model to simulate an aerodynamics performance of three different CMC blades and compared the predictions against the data acquired at NASA Glenn Transonic Turbine Blade Cascade Rig. Although we were able to successfully predict different characteristics of aerodynamic performance among three different blades (e.g., pressure loading and integrated losses), LES consistently predicted a small recirculation bubble at the end of the suction side. This was not inconsistent with the physics of the flow, but the pressure loading, locally, near the trailing edge, and as a result, the measured wake profiles did not match the experimental data. To delve further into these issues, a new LES grid with a much finer mesh near the trailing edge was generated where the spanwise extent of the grid was increased by 50%. An LES simulation for the CMC blade with the largest trailing edge thicknesses at the high-freestream turbulence (Tu=13%) condition showed that using such a mesh is necessary for LES to accurately capture the transition phenomena on the suction side. The resulting total pressure coefficient profile and the shift of the wake profile were greatly improved.

LES↗
NASA NTRSDate not supplied

An Overview of MaGIXS-2, The Second Flight of the Marshall Grazing Incidence X-ray Spectrometer

MaGIXS is a slitless soft X-ray (SXR) imaging spectrometer designed to observe solar active regions. - The instrument produces spatially resolved SXR spectra, known as “overlappograms.” (Athiray et al. 2019 & Champey et al., 2022) The first sounding rocket flight of the Marshall Grazing Incidence X-ray Spectrometer occurred on July 30, 2021 from the White Sands Missile Range, New Mexico. - Spectrally pure images of X-ray bright points were obtained through the inversion of overlappograms, e.g. Fig. 3 (Savage et al., 2022). MaGIXS 2 is a simplified version of the original design, less the spectrometer mirror pair. - Eliminating the spectrometer mirror pair improves spatial resolution, increases effective area and the field of view (Table 1). No field stop in this design, data will be an overlappogram with the same spatial and spectral plate scale.

x-ray spectrometer, x-ray optics, solar corona, so↗
NASA NTRSDate not supplied

Certification of Upper Air Sounding System to Support NASA Launch Operations

A new upper air sounding system (Vaisala MW51) has been installed at the United States Space Force’s Eastern Range (ER). The NASA Marshall Space Flight Center’s Natural Environments Branch has assessed MW51 test data from the ER to certify the new system for use in Artemis Program launch operations. Certification criteria are based on legacy system capabilities and vehicle design environments, and include criteria for wind, temperature, and relative humidity, as well as effective vertical resolution (EVR) of wind data. The test data consists of near simultaneous (within 15 seconds) releases of two MW51 sondes and one legacy system sonde. Difference statistics (root mean square) between MW51 and legacy system wind, temperature, and relative humidity data are assessed against the certification criteria. Wind data from dual MW51 releases are used in spectral/coherence analyses to assess the EVR criteria. The MW51 system must demonstrate it meets these criteria to be used in NASA Artemis launch operations.

Frank Leahy↗
NASA NTRS2001

The Effect of Ownship Information and NexRad Resolution on Pilot Decision Making in the Use of a Cockpit Weather Information Display

A two-phase experiment was conducted to explore the effects of data-link weather displays upon pilot decision performance. The experiment was conducted with 49 instrument rated pilots who were divided into four groups and placed in a simulator with a realistic flight scenario involving weather containing convective activity. The inflight weather display depicted NEXRAD images, with graphical and textual METARs over a moving map display. The experiment explored the effect of weather information, ownship position symbology and NEXRAD cell size resolution. The phase-two experiment compared two groups using the data-linked weather display with ownship position symbology. These groups were compared to the phase-one group that did not have ownship position symbology. The phase-two pilots were presented with either large NEXRAD cell size (8 km) or small cell size (4 km). Observations noted that the introduction of ownship symbology did not appear to significantly impact the decision making process, however, the introduction of ownship did reduce workload. Additionally, NEXRAD cell size resolution did appear to influence the tactical decision making process.

Novacek, Paul F.↗
NASA NTRS2006

Proceedings of the 2004 High Spatial Resolution Commercial Imagery Workshop

Topics covered include: NASA Applied Sciences Program; USGS Land Remote Sensing: Overview; QuickBird System Status and Product Overview; ORBIMAGE Overview; IKONOS 2004 Calibration and Validation Status; OrbView-3 Spatial Characterization; On-Orbit Modulation Transfer Function (MTF) Measurement of QuickBird; Spatial Resolution Characterization for QuickBird Image Products 2003-2004 Season; Image Quality Evaluation of QuickBird Super Resolution and Revisit of IKONOS: Civil and Commercial Application Project (CCAP); On-Orbit System MTF Measurement; QuickBird Post Launch Geopositional Characterization Update; OrbView-3 Geometric Calibration and Geopositional Accuracy; Geopositional Statistical Methods; QuickBird and OrbView-3 Geopositional Accuracy Assessment; Initial On-Orbit Spatial Resolution Characterization of OrbView-3 Panchromatic Images; Laboratory Measurement of Bidirectional Reflectance of Radiometric Tarps; Stennis Space Center Verification and Validation Capabilities; Joint Agency Commercial Imagery Evaluation (JACIE) Team; Adjacency Effects in High Resolution Imagery; Effect of Pulse Width vs. GSD on MTF Estimation; Camera and Sensor Calibration at the USGS; QuickBird Geometric Verification; Comparison of MODTRAN to Heritage-based Results in Vicarious Calibration at University of Arizona; Using Remotely Sensed Imagery to Determine Impervious Surface in Sioux Falls, South Dakota; Estimating Sub-Pixel Proportions of Sagebrush with a Regression Tree; How Do YOU Use the National Land Cover Dataset?; The National Map Hazards Data Distribution System; Recording a Troubled World; What Does This-Have to Do with This?; When Can a Picture Save a Thousand Homes?; InSAR Studies of Alaska Volcanoes; Earth Observing-1 (EO-1) Data Products; Improving Access to the USGS Aerial Film Collections: High Resolution Scanners; Improving Access to the USGS Aerial Film Collections: Phoenix Digitizing System Product Distribution; System and Product Characterization: Issues Approach; Innovative Approaches to Analysis of Lidar Data for the National Map; Changes in Imperviousness near Military Installations; Geopositional Accuracy Evaluations of QuickBird and OrbView-3: Civil and Commercial Applications Project (CCAP); Geometric Accuracy Assessment: OrbView ORTHO Products; QuickBird Radiometric Calibration Update; OrbView-3 Radiometric Calibration; QuickBird Radiometric Characterization; NASA Radiometric Characterization; Establishing and Verifying the Traceability of Remote-Sensing Measurements to International Standards; QuickBird Applications; Airport Mapping and Perpetual Monitoring Using IKONOS; OrbView-3 Relative Accuracy Results and Impacts on Exploitation and Accuracy Improvement; Using Remotely Sensed Imagery to Determine Impervious Surface in Sioux Falls, South Dakota; Applying High-Resolution Satellite Imagery and Remotely Sensed Data to Local Government Applications: Sioux Falls, South Dakota; Automatic Co-Registration of QuickBird Data for Change Detection Applications; Developing Coastal Surface Roughness Maps Using ASTER and QuickBird Data Sources; Automated, Near-Real Time Cloud and Cloud Shadow Detection in High Resolution VNIR Imagery; Science Applications of High Resolution Imagery at the USGS EROS Data Center; Draft Plan for Characterizing Commercial Data Products in Support of Earth Science Research; Atmospheric Correction Prototype Algorithm for High Spatial Resolution Multispectral Earth Observing Imaging Systems; Determining Regional Arctic Tundra Carbon Exchange: A Bottom-Up Approach; Using IKONOS Imagery to Assess Impervious Surface Area, Riparian Buffers and Stream Health in the Mid-Atlantic Region; Commercial Remote Sensing Space Policy Civil Implementation Update; USGS Commercial Remote Sensing Data Contracts (CRSDC); and Commercial Remote Sensing Space Policy (CRSSP): Civil Near-Term Requirements Collection Update.

Source record↗