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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 271 records · Page 15

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NASA NTRS1995

An airborne study of microwave surface sensing and boundary layer heat and moisture fluxes for FIFE

The objectives of this work were to perform imaging radar and scatterometer measurements over the Konza Prairie as a part of the First International land surface climatology project Field Experiments (EIFE) and to develop an mm-wave radiometer and the data acquisition system for this radiometer. We collected imaging radar data with the University of Kansas Side-Looking Airborne Radar (SLAR) operating at 9.375 GHz and scatterometer data with a helicopter-mounted scatterometer at 5.3 and 9.6 GHz. We also developed a 35-GHz null-balancing radiometer and data acquisition system. Although radar images showed good delineation of various features of the FIFE site, the data were not useful for quantitative analysis for extracting soil moisture information because of day-to-day changes in the system transfer characteristics. Our scatterometer results show that both C and X bands are sensitive to soil moisture variations over grass-covered soils. Scattering coefficients near vertical are about 4 dB lower for unburned areas because of the presence of a thatch layer, in comparison with those for burned areas. The results of the research have been documented in reports, oral presentations, and published papers.

Gogineni, S. P.↗

NASA NTRS1983

Fundamental research data base

A fundamental research data base containing ground truth, image, and Badhwar profile feature data for 17 North Dakota, South Dakota, and Minnesota agricultural sites is described. Image data was provided for a minimum of four acquisition dates for each site and all four images were registered to one another.

Source record↗

NASA NTRS1973

Design and evaluation of controls for drift, video gain, and color balance in spaceborne facsimile cameras

The facsimile camera is an optical-mechanical scanning device which has become an attractive candidate as an imaging system for planetary landers and rovers. This paper presents electronic techniques which permit the acquisition and reconstruction of high quality images with this device, even under varying lighting conditions. These techniques include a control for low frequency noise and drift, an automatic gain control, a pulse-duration light modulation scheme, and a relative spectral gain control. Taken together, these techniques allow the reconstruction of radiometrically accurate and properly balanced color images from facsimile camera video data. These techniques have been incorporated into a facsimile camera and reproduction system, and experimental results are presented for each technique and for the complete system.

Katzberg, S. J.↗

NASA NTRS1991

The Geologic Remote Sensing Field Experiment (GRSFE): The first geology multisensor airborne campaign

The primary objective of the Geologic Remote Sensing Field Experiment (GRSFE) is to acquire relevant data for geological sites that can be used to test models for extraction of surface property information from remote sensing data for earth, Mars and Venus in support of the Earth Observing System (EOS), Mars Observer, and Magellan, respectively. Over forty scientists from eight universities and three NASA centers are participating in GRSFE which is co-sponsored by the NASA Planetary Geology and Geophysics Program and the NASA Geology Program. Highlights of the airborne campaign included the first simultaneous acquisition of Airborne Visible and Infrared Imaging Spectrometer (AVRIS) and Thermal Infrared Multispectral Scanner (TIMS) data on September 29, 1989, and acquisition of Advanced Solid-State Array Spectroradiometer (ASAS), Polarimetric Synthetic Aperture Radar (AIRSAR), and Airborne Terrain Laser Altimeter System (ATLAS) data all within three months of each other. The sites covered were Lunar Crater Volcanic Field and Fish Lake Valley in Nevada; and Cima Volcanic Field, Death Valley, and Ubehebe Crater in California. Coincident field measurements included meteorological and atmospheric measurements, visible/near-infrared and thermal spectra, and characterization of geology and vegetation cover. The GRSFE airborne and field data will be reduced to a suite of standard products and submitted, along with appropriate documentation, to the Planetary Data System (PDS) and the Pilot Land Data System (PLDS). These data will be used for a variety of investigations including paleoclimatic studies in the arid southwestern United States, and analysis of Magellan data. GRSFE data will also be used to support Mars Observer Laser Altimeter (MOLA) and Mars Rover Sample Return (MRSR) simulation studies.

Evans, Diane L.↗

NASA NTRS1973

A study of morphology, provenance, and movement of desert sand seas in Africa, Asia, and Australia

The author has identified the following significant results. The assembling of photomosaics from color prints of ERTS images has made possible the recognition and description of san patterns, and these are to be the basis of a worldwide classification of sand bodies. Progress has been as rapid as the acquisition of the bulk composite images will permit and for some areas the mosaics are now nearly complete. A second step, which consists of the accumulation and analysis of regional wind data, to be plotted as overlays for the dune patterns, is now underway and should soon give tangible results. Other aspects of the project include the gathering of ground truth in the form of air photographs, needed to interpret geomorphic forms and the sampling of sand deposits for analyzing the texture and composition of sand bodies. A start has been made on these studies in several selected areas.

Mckee, E. D.↗

NASA NTRS2010

Noninvasive Techniques for Intracranial Pressure Assessment: A Review from Aerospace Medicine Perspective

Microgravity-induced changes in fluid distribution and other physiological factors due to space flight have been implicated as the cause of increased intracranial pressure (ICP) in a number of space crewmembers. The modest levels of ICP elevation and absence of severe symptoms in this group do not warrant invasive diagnostic interventions. However, the long-term trends and residual or consequential changes secondary to the observed ICP elevation in this group are not yet known. Therefore, close attention is needed to evaluate the potential techniques of noninvasively assessing ICP, including those feasible for in-flight use. Of particular interest is continuity between ground and in-flight testing, whereby data from the same or different techniques allow reasonably dependable estimation of ICP trends and responses. Methods: A thorough review of current literature, analysis of NASA data, and interviews with subject matter experts were conducted to construct a presentation that reflects the state of the art for noninvasive ICP measurement and monitoring. Results: Multiple imaging and non-imaging modalities are available to assess ICP in terrestrial clinical and experimental environments. Imaging alternatives include magnetic resonance imaging (MRI) and high-resolution sonography. Non-imaging techniques include transcranial Doppler, certain audiological methods, and venous ophthalmodynamometry, among others. Special functional techniques have been proposed recently that allow the use of advanced MRI methods to calculate ICP in addition to the acquisition of high-resolution images. Our data include many of these applications, with several cases of correlation with lumbar puncture, the invasive "gold standard" measurement of ICP.

Hamilton, Douglas R.↗

NASA NTRS2012

Projection of Stabilized Aerial Imagery Onto Digital Elevation Maps for Geo-Rectified and Jitter-Free Viewing

As imagery is collected from an airborne platform, an individual viewing the images wants to know from where on the Earth the images were collected. To do this, some information about the camera needs to be known, such as its position and orientation relative to the Earth. This can be provided by common inertial navigation systems (INS). Once the location of the camera is known, it is useful to project an image onto some representation of the Earth. Due to the non-smooth terrain of the Earth (mountains, valleys, etc.), this projection is highly non-linear. Thus, to ensure accurate projection, one needs to project onto a digital elevation map (DEM). This allows one to view the images overlaid onto a representation of the Earth. A code has been developed that takes an image, a model of the camera used to acquire that image, the pose of the camera during acquisition (as provided by an INS), and a DEM, and outputs an image that has been geo-rectified. The world coordinate of the bounds of the image are provided for viewing purposes. The code finds a mapping from points on the ground (DEM) to pixels in the image. By performing this process for all points on the ground, one can "paint" the ground with the image, effectively performing a projection of the image onto the ground. In order to make this process efficient, a method was developed for finding a region of interest (ROI) on the ground to where the image will project. This code is useful in any scenario involving an aerial imaging platform that moves and rotates over time. Many other applications are possible in processing aerial and satellite imagery.

Ansar, Adnan I.↗

NASA NTRS2003

THEMIS Visible Imaging of the South Polar Layered Deposits, Martian Southern Spring, 2003

The polar layered deposits (PLD) of Mars have attracted considerable attention since their identification in Mariner 9 images, largely due to the possibility that these finely layered, volatile-rich deposits hold a record of recent eras in Martian climate history. The PLD have been a target of imaging and other sensors in the last several decades, but only recently has it been possible to obtain a moderately high resolution image map, using the visible sensor on 2001 Mars Odyssey s Thermal Emission Imaging System (THEMIS). We report here on the acquisition of a 36 meter/pixel contiguous single-band visible image data set of the south polar layered deposits (SPLD), obtained during early southern spring in 2003. The data will undoubtedly be applied to many problems in Mars polar studies. We will discuss here, and in more detail at the Conference, the use of these images to further characterize the population of impact craters on the SPLD, and the implications of the observed population for the age and evolution of the SPLD.

Plaut, J. J.↗

NASA NTRS2003

Themis Visible Imaging of the South Polar Layered Deposits, Martian Southern Spring, 2003

The polar layered deposits (PLD) of Mars have attracted considerable attention since their identification in Mariner 9 images, largely due to the possibility that these finely layered, volatile-rich deposits hold a record of recent eras in Martian climate history. The PLD have been a target of imaging and other sensors in the last several decades, but only recently has it been possible to obtain a moderately high resolution image map, using the visible sensor on 2001 Mars Odyssey's Thermal Emission Imaging System (THEMIS). We report here on the acquisition of a 36 meter/pixel contiguous single-band visible image data set of the south polar layered deposits (SPLD), obtained during early southern spring in 2003. The data will undoubtedly be applied to many problems in Mars polar studies.

Mariner 9↗

NASA NTRS1981

Comparison of wheat classification accuracy using different classifiers of the image-100 system

Classification results using single-cell and multi-cell signature acquisition options, a point-by-point Gaussian maximum-likelihood classifier, and K-means clustering of the Image-100 system are presented. Conclusions reached are that: a better indication of correct classification can be provided by using a test area which contains various cover types of the study area; classification accuracy should be evaluated considering both the percentages of correct classification and error of commission; supervised classification approaches are better than K-means clustering; Gaussian distribution maximum likelihood classifier is better than Single-cell and Multi-cell Signature Acquisition Options of the Image-100 system; and in order to obtain a high classification accuracy in a large and heterogeneous crop area, using Gaussian maximum-likelihood classifier, homogeneous spectral subclasses of the study crop should be created to derive training statistics.

Dejesusparada, N.↗

NASA NTRS1991

Applied high-speed imaging for the icing research program at NASA Lewis Research Center

The Icing Research Tunnel at NASA Lewis Research Center provides scientists a scaled, controlled environment to simulate natural icing events. The closed-loop, low speed, refrigerated wind tunnel offers the experimental capability to test for icing certification requirements, analytical model validation and calibration techniques, cloud physics instrumentation refinement, advanced ice protection systems, and rotorcraft icing methodology development. The test procedures for these objectives all require a high degree of visual documentation, both in real-time data acquisition and post-test image processing. Information is provided to scientific, technical, and industrial imaging specialists as well as to research personnel about the high-speed and conventional imaging systems will be on the recent ice protection technology program. Various imaging examples for some of the tests are presented. Additional imaging examples are available from the NASA Lewis Research Center's Photographic and Printing Branch.

Slater, Howard↗

NASA NTRS1992

Applied high-speed imaging for the icing research program at NASA Lewis Research Center

Slater, Howard↗

NASA NTRS2010

Finding Interstellar Particle Impacts on Stardust Aluminium Foils: The Safe Handling, Imaging, and Analysis of Samples Containing Femtogram Residues

Impact ionisation detectors on a suite of spacecraft have shown the direction, velocity, flux and mass distribution of smaller ISP entering the Solar System. During the aphelion segments of the Stardust flight, a dedicated collector surface was oriented to intercept ISP of beta = 1, and returned to Earth in January 2006. In this paper we describe the probable appeareance and size of IS particle craters from initial results of experimental impacts and numerical simulation, explain how foils are being prepared and mounted for crater searching by automated acquisition of high magnification electron images (whilst avoiding contamination of the foils) and comment on appropriate analytical techniques for Preliminary Examination (PE).

Kearsley, A. T.↗

NASA NTRS2005

An Analysis of Spacecraft Localization from Descent Image Data for Pinpoint Landing on Mars and other Cratered Bodies Data Acquisition

A pinpoint landing capability will be a critical component for many planned NASA missions to Mars and beyond. Implicit in the requirement is the ability to accurately localize the spacecraft with respect to the terrain during descent. In this paper, we present evidence that a vision-based solution using craters as landmarks is both practical and will meet the requirements of next generation missions. Our emphasis in this paper is on the feasibility of such a system in terms of (a) localization accuracy and (b) applicability to Martian terrain. We show that accuracy of well under 100 meters can be expected under suitable conditions. We also present a sensitivity analysis that makes an explicit connection between input data and robustness of our pose estimate. In addition, we present an analysis of the susceptibility of our technique to inherently ambiguous configurations of craters. We show that probability of failure due to such ambiguity is becoming increasingly small.

landforms↗

NASA NTRS2005

Imaging Dot Patterns for Measuring Gossamer Space Structures

A paper describes a photogrammetric method for measuring the changing shape of a gossamer (membrane) structure deployed in outer space. Such a structure is typified by a solar sail comprising a transparent polymeric membrane aluminized on its Sun-facing side and coated black on the opposite side. Unlike some prior photogrammetric methods, this method does not require an artificial light source or the attachment of retroreflectors to the gossamer structure. In a basic version of the method, the membrane contains a fluorescent dye, and the front and back coats are removed in matching patterns of dots. The dye in the dots absorbs some sunlight and fluoresces at a longer wavelength in all directions, thereby enabling acquisition of high-contrast images from almost any viewing angle. The fluorescent dots are observed by one or more electronic camera(s) on the Sun side, the shade side, or both sides. Filters that pass the fluorescent light and suppress most of the solar spectrum are placed in front of the camera(s) to increase the contrast of the dots against the background. The dot image(s) in the camera(s) are digitized, then processed by use of commercially available photogrammetric software.

Dorrington, A. A.↗

NASA NTRS1991

Geometric rectification and geocoding of JPL's AIRSAR data over hilly terrain

A post-processing system was developed to georeference and geocode airborne synthetic aperture radar (SAR) data collected by the JPL-Airborne SAR (AIRSAR) System over hilly terrain during the 1990 MAESTRO1 campaign. Georectification relates image coordinates and object coordinates while the geocoding involves resampling. The georectification method uses a hybrid method based upon a number of navigational parameters and minimal two ground-control points which are referenced in both image and map space. The calculation of the intersection of the SAR signal wavefront and a digital elevation model allowed, within certain error bounds, acquisition of the object-to-image and image-to-object relationships.

Degroof, H.↗

NASA NTRS1985

Preliminary evaluation of the airborne imaging spectrometer for vegetation analysis in the Klamath National Forest of northeastern California

The experiences and results associated with a project entitled Preliminary Evaluation of the Airborne Imaging Spectrometer for Vegetation Analysis is documented. The primary goal of the project was to provide ground truth, manual interpretation, and computer processing of data from an experimental flight of the Airborne Infrared Spectrometer (AIS) to determine the extent to which high spectral resolution remote sensing could differentiate among plant species, and especially species of conifers, for a naturally vegetated test site. Through the course of the research, JPL acquired AIS imagery of the test areas in the Klamath National Forest, northeastern California, on two overflights of both the Dock Well and Grass Lake transects. Over the next year or so, three generations of data was also received: first overflight, second overflight, and reprocessed second overflight. Two field visits were made: one trip immediately following the first overflight to note snow conditions and temporally-related vegetation states at the time of the sensor overpass; and a second trip about six weeks later, following acquisition of prints of the images from the first AIS overpass.

Strahler, A. H.↗

NASA NTRS2001

Seismic Forecasting of Solar Activity

We have developed and improved helioseismic imaging techniques of the far-side of the Sun as part of a synoptic monitor of solar activity. In collaboration with the MIDI team at Stanford University we are routinely applying our analysis to images within 24 hours of their acquisition by SOHO. For the first time, real-time seismic maps of large active regions on the Sun's far surface are publicly available. The synoptic images show examples of active regions persisting for one or more solar rotations, as well as those initially detected forming on the solar far side. Until recently, imaging the far surface of the Sun has been essentially blind to active regions more than about 50 degrees from the antipode of disk center. In a paper recently accepted for publication, we have demonstrated how acoustic travel-time perturbations may be mapped over the entire hemisphere of the Sun facing away from the Earth, including the polar regions. In addition to offering significant improvements to ongoing space weather forecasting efforts, the procedure offers the possibility of local seismic monitoring of both the temporal and spatial variations in the acoustic properties of the Sun over the entire far surface.

Braun, Douglas↗