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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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At least 847 records · Page 47
All sourcesNASA NTRSDOE OSTI
NASA NTRS1977

The Pioneer Venus program

Mission timetables, spacecraft, scientific objectives, and payloads of the two mission, Orbiter and Multiprobe, planned for launch and encounter with Venus during the 1978 Venus mission opportunity are described. Basically, the Orbiter mission has the goal of global mapping of the clouds, atmosphere and ionosphere of Venus by remote sensing and radio occultation, global studies by in situ measurements of the upper atmosphere and ionosphere and solar wind-ionosphere interaction region, and determination of gravitational field harmonics from perturbations of the spacecraft orbit. The Multiprobe mission will study the nature and composition of the clouds, the structure of the atmosphere, the circulation pattern, and the characteristics of the planetary environmental interaction with the solar wind.

Colin, L.↗
NASA NTRS1990

Basic data requirements for microwave radiometer systems

Microwave radiometry has emerged over the last two decades to become an integral part of the field of environmental remote sensing. Numerous investigations were conducted to evaluate the use of microwave radiometry for atmospheric, oceanographic, hydrological, and geological applications. Remote sensing of the earth using microwave radiometry began in 1968 by the Soviet satellite Cosmos 243, which included four microwave radiometers (Ulably, 1981). Since then, microwave radiometers were included onboard many spacecraft, and were used to infer many physical parameters. Some of the basic concepts of radiometric emission and measurement will be discussed. Several radiometer systems are presented and an overview of their operation is discussed. From the description of the radiometer operation the data stream required from the radiometer and the general type of algorithm required for the measurement is discussed.

Lawrence, R. W.↗
NASA NTRS1995

Analysis of measurements for solid state laser remote lidar system

The merits of using lidar systems for remote measurements of various atmospheric processes such as wind, turbulence, moisture, and aerosol concentration are widely recognized. Although the lidar technology has progressed considerably over the past two decades, significant research particularly in the area of solid state lidars remains to be conducted in order to fully exploit this technology. The work performed by the UAH (University of Alabama in Huntsville) personnel under this Delivery Order concentrated on analyses of measurements required in support of solid state laser remote sensing lidar systems which are to be designed, deployed, and used to measure atmospheric processes and constituents. UAH personnel has studied and recommended to NASA/MSFC the requirements of the optical systems needed to characterize the detection devices suitable for solid state wavelengths and to evaluate various heterodyne detection schemes. The 2-micron solid state laser technology was investigated and several preliminary laser designs were developed and their performance for remote sensing of atmospheric winds and clouds from a spaceborne platform were specified. In addition to the laser source and the detector, the other critical technologies necessary for global wind measurements by a spaceborne solid state coherent lidar systems were identified to be developed and demonstrated. As part of this work, an analysis was performed to determine the atmospheric wind velocity estimation accuracy using the line-of-sight measurements of a scanning coherent lidar. Under this delivery order, a computer database of materials related to the theory, development, testing, and operation of lidar systems was developed to serve as a source of information for lidar research and development.

Amzajerdian, Farzin↗
NASA NTRS2023

Unifying radiative transfer models in computer graphics and remote sensing, Part I: A Survey

The constellation of Earth-observing satellites continuously collects measurements of scattered radiance, which must be transformed into geophysical parameters in order to answer fundamental scientific questions about the Earth. Retrieval of these parameters requires highly flexible, accurate, and fast forward and inverse radiative transfer models. Existing forward models used by the remote sensing community are typically accurate and fast, but sacrifice flexibility by assuming the atmosphere or ocean is composed of plane-parallel layers. Monte Carlo forward models can handle more complex scenarios such as 3D spatial heterogeneity, but are relatively slower. We propose looking to the computer graphics community for inspiration to improve the statistical efficiency of Monte Carlo forward models and explore new approaches to inverse models for remote sensing. In Part 1 of this work, we examine the evolution of radiative transfer models in computer graphics and highlight recent advancements that have the potential to push forward models in remote sensing beyond their current periphery of realism.

Radiative transfer↗
NASA NTRSDate not supplied

High Flying Interns: NASA's Student Airborne Research Program

The NASA Student Airborne Research Program is an annual summer internship for upper-level undergraduate STEM majors. Each summer since 2009, we have competitively selected ~30 undergraduates from colleges and universities across the United States for this unique airborne research experience. In all past summers, students flew onboard a NASA research aircraft where they assisted in the operation of remote sensing and in situ instrumentation to study the Earth, ocean, and atmosphere. Students also participated in field trips where they acquired data to ground-truth and complement the airborne data. After their flights and field trips, students then spent the rest of summer developing individual research projects using the data they collected as well as data from previous year SARP flights, other NASA airborne campaigns, and NASA satellite data. This summer, we adapted the program to be entirely online. Each of the 28 undergraduate students still completed an individual research project using data from previous SARP flights as well as publicly available data from other airborne campaigns, satellites, and/or ground stations. Students were mentored remotely by five university faculty members, five graduate students, and several additional scientists and engineers from NASA. In order to preserve some aspects of the hands-on research experience, we also shipped each student a box of twenty-four Whole Air Sampling canisters identical to what they would have used to collect air samples onboard the NASA aircraft. Instead, each student collected ground samples near their home starting in mid-April through July. The goal of this sampling was to attempt to characterize the impacts of pandemic-related changes in emissions with time across the United States. The results of that ground sampling are being presented in scientific sessions in this meeting. In addition, students also measured PM2.5 and aerosol optical depth from June through August using sensors provided by the Citizen-Enabled Aerosol Measurements for Satellites (CEAMS) at Colorado State University. We will discuss strategies we employed to conduct research online, the unexpected opportunities that arose, and lessons learned.

STEM disciplines↗
NASA NTRS1997

Analysis of Vegetation and Atmospheric Correction Indices for Landsat Images

Vegetation and Atmospheric Indices are mathematical combinations of remote sensing bands which are useful in distinguishing the various values of the spectral reflectance. In this paper we study how the applications of various atmospherically corrected indices and vegetation indices can aide in retrieving the amount of surface reflectance from a remotely sensed image. Specifically, this paper studies and compares three vegetation indices and one atmospherically resistant index. These indices include the Normalized Difference Vegetation Index (NDVI), the Soil Adjusted Vegetation Index (SAVI), the Green Vegetation Index (GVI), and the Atmospherically Resistant Vegetation Index (ARVI), respectively. The algorithms attempt to estimate the optical characteristics of Thematic Mapper (TM) imagery. It will be shown that the NDVI algorithm followed by the ARVI correcting algorithm provided significant improvements in the tonal qualities of the retrieved images. The results are presented on 1987 TM images over the Kennedy Space Center (KSC) and are compared with a set of United States Geological Survey (U.S.G.S) maps.

Bush, Tasha R.↗
NASA NTRS2024

Basalt Alteration in a CO 2 -SO 2 Atmosphere: Implications for Surface Processes on Venus

Venus’ surface and interior dynamics remain largely unconstrained, due in great part to the major obstacles to exploration imposed by its 470°C, 90 bar surface conditions and its thick, opaque atmosphere. Orbiter-based thermal emission data provide opportunities to characterize the surface composition of Venus. However, interpretations of such spectra depend on understanding interactions between the planet’s surface basaltic rocks and its caustic, sulfur dioxide (SO 2 )-bearing carbon dioxide (CO 2 ) atmosphere. Several studies, using remote sensing, thermodynamic modeling, and laboratory experiments, have placed constraints on basaltic alteration mineralogies and rates. Yet constraint with respect to SO 2 -mediated reactions with basalts of contrasting compositions remains incomplete. Here, we present new data from a series of gas-solid reaction experiments, in which samples of two basalt compositions were reacted in an SO 2 -bearing CO 2 atmosphere, at relevant Venus temperatures, pressure, and oxygen fugacity. We subjected reacted specimens to scanning electron microscopy (SEM) and scanning transmission electron microscopy (STEM) analyses using sample cross-sections produced with focused ion beam (FIB) milling. Surface alteration products were characterized, and their abundances estimated; subsurface cation concentrations were mapped to show depth of alteration. We demonstrate that the initial rate of reaction in our experiments is very rapid. Alkaline basalt samples are coated by (meta)thenardite (Na 2 SO 4 ) and amorphous calcium carbonate (CaCO 3 ) alteration products, and tholeiitic basalt samples are primarily covered by anhydrite (CaSO 4 ), Fe-oxide (Fe x O y : likely magnetite, Fe 3 O 4 ), and other minor phases.

Venus↗
NASA NTRS1993

(abstract) Hermes Global Orbiter: Mission to Mercury

The Hermes Global Orbiter is a proposed Discovery-class mission. Hermes will be launched aboard a Delta II rocket in 1999 and will be placed in an elliptical polar orbit about Mercury. Remote sensing measurements of the planet's surface, atmosphere, and magnetosphere will be performed. Key mission goals include mapping the entire surface at 1 km resolution, characterizing the surface composition, texture and topography, searching for water ice at the poles, characterizing the atmosphere, and constraining the interior structure.

Mercury Hermes orbiter remote sensing surface atmo↗
NASA NTRS2001

Remote Sensing of Cloud, Aerosol, and Water Vapor Properties from MODIS

MODIS is an earth-viewing cross-track scanning spectroradiometer launched on the Terra satellite in December 1999. MODIS scans a swath width sufficient to provide nearly complete global coverage every two days from a polar-orbiting, sun-synchronous, platform at an altitude of 705 km, and provides images in 36 spectral bands from 0.415 to 14.235 microns with spatial resolutions of 250 m (2 bands), 500 m (5 bands) and 1000 m (29 bands). These bands have been carefully selected to enable advanced studies of land, ocean, and atmospheric processes. In this presentation I will review the comprehensive set of remote sensing algorithms that have been developed for the remote sensing of atmospheric properties using MODIS data, placing primary emphasis on the principal atmospheric applications of: (1) developing a cloud mask for distinguishing clear sky from clouds, (2) retrieving global cloud radiative and microphysical properties, including cloud top pressure and temperature, effective emissivity, cloud optical thickness, thermodynamic phase, and effective radius, (3) monitoring tropospheric aerosol optical thickness over the land and ocean and aerosol size distribution over the ocean, (4) determining atmospheric profiles of moisture and temperature, and (5) estimating column water amount. The physical principles behind the determination of each of these atmospheric products will be described, together with an example of their application using MODIS observations. All products are archived into two categories: pixel-level retrievals (referred to as Level-2 products) and global gridded products at a latitude and longitude resolution of 1 deg (Level-3 products). An overview of the MODIS atmosphere algorithms and products, status, validation activities, and early level-2 and -3 results will be presented. Finally, I will present some highlights from the land and ocean algorithms developed for processing global MODIS observations, including: (1) surface reflectance, (2) vegetation indices, leaf area index, and FPAR, (3) albedo and nadir BRDF-adjusted reflectance, (4) normalized water-leaving radiance, (5) chlorophyll-a concentration, and (6) sea surface temperature.

King, Michael D.↗
DOE OSTI2025

Editorial for the Collection "Preparatory Work for the American Wake Experiment (AWAKEN)"

The American WAKE experimeNt (AWAKEN) is a large field campaign focused on gathering observations for improved understanding of atmospheric and wind power plant flow physics, one of the outstanding needs for the wind energy community as described in the Science paper by Veers et al.1 "Grand challenges in wind energy." AWAKEN was planned over several years with an international consortium of numerous stakeholders, including national laboratories, academic researchers, wind turbine manufacturers, and wind farm operators. A highlight of the AWAKEN campaign is the extensive use of remote sensing instrumentation to characterize the atmosphere and its interactions with wind power plants, enabled by recent developments in lidar, radar, and thermodynamic profiling technology. Advanced modeling techniques like mesoscale and large-eddy simulations (LES) also played an important role in the preparation of the experiment and the interpretation of the experimental data collected. This special-topic issue for the Journal of Renewable and Sustainable Energy presents a collection of 12 papers that describe the preparatory work and some initial analyses from the AWAKEN campaign. An overview of the contents of the various papers in this special issue is provided in Sec. II.

17 WIND ENERGY↗
DOE OSTI2022

Fast response High Altitude Laser Optical Sensor (HALOS) for atmospheric water and temperature measurements

Advanced instrumentation and sensing methods are the key factor in the determination of many climate science research problems. In this Phase I STTR a laser-based diagnostic system for atmospheric temperature and water concentrations measurements was developed, this system, HALOS – High Altitude Laser Optical Sensor, employs a mid-infrared (MIR) quantum cascade laser (QCL) of the distributed feedback variety (DFB) powered by a 100 kHz rep rate ramp modulated current profile which enables spectral profiling. Measurements made during Phase I showed that HALOS can surpass the available hygrometers refresh rates while offering superior accuracy (<4%) from the low Frost Point (Tfrost) of -110°C to dew points (Tdew) at 35°C while being able to encompass sub ppm concentration at altitude and supersaturated conditions at ground level. Readings from HALOS include temperature sensitivity on the order of 0.2°C and absolute humidity sensitivity (AH) on the order of 0.010 μmol/m 3 (0.18 mg/m 3 ) at a data output rate exceeding 1 kHz. HALOS can be easily integrable in existing Department of Energy (DOE) or National Oceanic and Atmospheric Administration (NOAA) conventional or remote operated aircraft having either a fixed or rotary wing.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS1982

Radiative transfer and remote sensing

Radiative transfer, the basic theoretical tool for the quantitative interpretation of planetary infrared spectra, is discussed. The function it plays in linking the remotely sensed data to the properties of the atmosphere (composition, thermal structure, dynamics, etc.), is inferred. A brief overview of the remote sensing problem as it pertains to the interpretation of planetary spectra is presented. The presentation is tutorial rather than exhaustive.

Conrath, B. J.↗
NASA NTRS1988

Phase-Length Optical Phase-Locked-Loop Sensor (PLOPS)

PLOPS system designed to provide high-resolution measurement of change in optical length from optical-system source to any optical reflector, including diffuse reflector. Serves as adjustable optical ruler, providing high resolution in measurements of small and large changes in distance to target. Use is broad and includes most measurement situations requiring information on length, vibration, and their derivatives. Applications include building dynamics, remote sensing of vibrations in such systems as turbine-based machinery, monitoring of structural dynamics, noncontacting sensing of surface contours, measurement of large strains as in earthquake monitoring, measurement of atmospheric dynamics and turbulence, high-resolution sensing of humidity, detection of surface acoustic waves by optical microscopy, and related areas.

Heyman, Joseph S.↗
DOE OSTI2025

Best estimate of the planetary boundary layer height from multiple remote sensing measurements

Remote sensing measurements have been widely used to estimate the planetary boundary layer height (PBLHT). Each remote sensing approach offers unique strengths and faces different limitations. In this study, we use machine learning (ML) methods to produce a best-estimate PBLHT (PBLHT-BE-ML) by integrating four PBLHT estimates derived from remote sensing measurements at the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) observatory. Three ML models – random forest (RF) classifier, RF regressor, and light gradient-boosting machine (LightGBM) – were trained on a dataset from 2017 to 2023 that included radiosonde, various remote sensing PBLHT estimates, and atmospheric meteorological conditions. Evaluations indicated that PBLHT-BE-ML from all three models improved alignment with the PBLHT derived from radiosonde data (PBLHT-SONDE), with LightGBM demonstrating the highest accuracy under both stable and unstable boundary layer conditions. Feature analysis revealed that the most influential input features at the SGP site were the PBLHT estimates derived from (a) potential temperature profiles retrieved using Raman lidar (RL) and atmospheric emitted radiance interferometer (AERI) measurements (PBLHT-THERMO), (b) vertical velocity variance profiles from Doppler lidar (PBLHT-DL), and (c) aerosol backscatter profiles from micropulse lidar (PBLHT-MPL). The trained models were then used to predict PBLHT-BE-ML at a temporal resolution of 10 min, effectively capturing the diurnal evolution of PBLHT and its significant seasonal variations, with the largest diurnal variation observed over summer at the SGP site. We applied these trained models to data from the ARM Eastern Pacific Cloud Aerosol Precipitation Experiment (EPCAPE) field campaign (EPC), where the PBLHT-BE-ML, particularly with the LightGBM model, demonstrated improved accuracy against PBLHT-SONDE. Analyses of model performance at both the SGP and EPC sites suggest that expanding the training dataset to include various surface types, such as ocean and ice-covered areas, could further enhance ML model performance for PBLHT estimation across varied geographic regions.

Zhang, Damao [Pacific Northwest National Laborator↗
NASA NTRS1994

Observations in the solar spectrum interest for remote sensing purposes

The polarization of the sunlight scattered by atmospheric aerosols or cloud droplets and reflected from ground surfaces or plant canopies may convey much information when used for remote sensing purposes. The typical polarization features of aerosols, cloud droplets, and plant canopies, as observed by ground based and airborne sensors, are investigated, looking especially for those invariant properties amenable to description by simple models when possible. The question of polarization measurements from space is addressed. The interest of such measurements for remote sensing purposes is investigated, and their feasibility is tested by using results obtained during field campaigns of the airborne POLDER instrument, a radiometer designed to measure the directionality and polarization of the sunlight scattered by the ground atmosphere system.

Herman, M.↗
NASA NTRS2012

The Extreme Ultraviolet (EUV) Instrument for the MAVEN Mission

The Mars Atmosphere and Volatile Evolution Mission (MAVEN) will explore the variability in the planet's upper atmosphere and ionosphere that is dominated by interactions with the sun, specifically the high-energy photons in the soft X-ray and extreme ultraviolet wavelengths as well as interactions with the solar wind. Scientists will use MAVEN data to determine the current loss rate of volatile compounds from the Mars atmosphere, then extrapolate back in time in order to give historical estimations of state of the Mars atmosphere and climate, its ability to sustain liquid water, and the potential for the Martian habitability. The EUV instrument is critical in measuring the Space Weather driver of this atmospheric variability. It will directly observe a three EUV wavelength ranges and their variability due to solar flares (time scales of seconds to hours) as well as active region evolution (months), which will then act as proxies for a model to determine the entire 0.1-200 nm solar spectrum at all times during the MAVEN mission. These EUV measurements and models results will compliment the other instruments that will provide direct in-situ as well as remote sensing observations of the Martian atmospheric response to this solar driver. This presentation will be an introduction of this instrument and its science measurements and goals to the larger community, as well as a status report on its progress.

Chamberlin, Phillip C.↗
NASA NTRS2004

Neutral Mass Spectrometry for Venus Atmosphere and Surface

The nature of the divergent evolution of the terrestrial planets Venus, Earth, and Mars is a fundamental problem in planetary science that is most relevant to understanding the characteristics of small planets we are likely to discover in extrasolar systems and the number of such systems that may support habitable environments. For this reason, the National Research Council's Decadal Survey gives Venus exploration high priority. That report was the basis of the NASA selection of Venus as one of four prime mission targets for the recently initiated New Frontiers Program. If the Decadal Survey priorities are to be realized, in situ Venus exploration must remain a high priority. Remote sensing orbital and in situ atmospheric measurements from entry probe or balloon platforms might be realized under the low cost Discovery missions while both atmospheric and landed surface measurements are envisioned with the intermediate class missions of the New Frontiers Program.

Mahaffy, Paul↗