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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 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
NASA NTRS1990

Docking alignment system

Improved techniques are provided for alignment of two objects. The present invention is particularly suited for three-dimensional translation and three-dimensional rotational alignment of objects in outer space. A camera 18 is fixedly mounted to one object, such as a remote manipulator arm 10 of the spacecraft, while the planar reflective surface 30 is fixed to the other object, such as a grapple fixture 20. A monitor 50 displays in real-time images from the camera, such that the monitor displays both the reflected image of the camera and visible markings on the planar reflective surface when the objects are in proper alignment. The monitor may thus be viewed by the operator and the arm 10 manipulated so that the reflective surface is perpendicular to the optical axis of the camera, the roll of the reflective surface is at a selected angle with respect to the camera, and the camera is spaced a pre-selected distance from the reflective surface.

Monford, Leo G.↗
DOE OSTI2026

Adaptive optical correction for in vivo two-photon fluorescence microscopy with neural fields

Adaptive optics restore ideal imaging performance in complex samples by measuring and correcting optical aberrations but often require custom-built microscopes with carefully aligned wavefront sensing/shaping devices and can be susceptible to sample motion. Here we describe NeAT, a computational framework using neural fields for adaptive optics two-photon fluorescence microscopy. NeAT estimates wavefront aberration and recovers sample structure from a 3D image stack without requiring external datasets for training. Incorporating motion correction in learning and correcting conjugation errors commonly found in commercial microscopes, NeAT is designed for deployment in biological laboratories for in vivo imaging. We validate NeAT’s performance using a custom-built microscope with a wavefront sensor under varying signal-to-noise ratios, aberration and motion conditions. With a commercial microscope, we demonstrate real-time aberration correction for in vivo morphological and functional imaging in the living mouse brain, with NeAT improving the signal and accuracy of glutamate and calcium imaging of synapses and neurons.

Kang, Iksung↗
NASA NTRS1980

Application of optimum smoothing for image distortion correction

Optimum linear smoothing is utilized to estimate certain distortions in LANDSAT-D images. Measurements that are processed by the smoother consist of designated control of point locations within the images. Image distortions that are estimated by the smoother are those induced by LANDSAT-D satellite navigation errors and slowly varying attitude and sensor alignment uncertainties. Preliminary results indicate that optimum smoothing produces substantially more accurate distortion estimates than optimum filtering and that optimum smoothing may reduce the number of control points needed to yield desired image correction accuracy.

Werner, R. A.↗
NASA NTRS1994

Interpretation of microlensing events in Q2237 + 0305

We point out the uncertainties in the potential models of the foreground galaxy in the gravitational lens Q2237 + 0305. The surface densities and external shears are uncertain by a factor of appproximately less than 2. Very long light curves are calculated for different models using the method developed by Witt (1993) and Lewis et al. (1993). We find that the probability of images being in a quiescent state depends strongly on the potential models and the direction of the source motion relative to the alignment of the (gravitational lens) shear term of the macroimages. For example, the probabilities of finding variations smaller than 0.1 mag and for a period of longer than 0.5 Einstein radii (approximately equals 3-5 yr) in image C and D are approximately 30%. This offers an explanation of why image C and D showed relatively small variations. The quiescent images are more likely to be demagnified, consistent with the observations. Further, the higher the magnification of the macroimages, the weaker are the microlensing events. In addition, we conclude that a simple Gaussian profile has some difficulties in explaining the asymmetric shape and the small amplitude of the observed high-magnification events if they are typical. Source models in which the emission is produced by a brightt compact core and a more extended halo can occur better explain the observed double peak events. More data are needed to clearly distinguish different galaxy potential models.

Witt, Hans J.↗
NASA NTRS1974

Hydrologic applications of Nimbus 5 ESMR data

A region of low brightness temperature lying along the Mississippi River from Cairo, Illinois, to Morganza, Louisiana was observed in early Nimbus 5 Electrically Scanning Microwave Radiometer images. This region, which generally corresponds to an outwash aquifer in the Mississippi Valley, had brightness temperatures, at times as much as 40 K below the surrounding (drier) older uplands. Fluctuations of as much as 30 K were observed during the time interval 15 December 1972 to 28 February 1973. Comparison images taken from the Earth Resources Technology Satellite indicate that the study area is aligned with the Mississippi River floodplain, a region of potentially high soil moisture content. The brightness temperature fluctuations were compared with variations in precipitation and other hydrologic parameters in order to delineate the causative factors.

Schmugge, T. J.↗
NASA NTRS1977

Gregorian all-reflective optical system

An optical heterodyne receiver comprises a system of reflectors forming a folded Gregorian configuration for collecting a signal beam, and an optical detector located at the focus of the system. A paraboloidal primary reflector and an elipsoidal secondary reflector face each other on an optical axis with the focus of the secondary reflector coinciding with the focus of the primary reflector. An auxiliary laser generates a local oscillator beam that is combined with the signal beam after the signal beam emerges from the exit pupil (which is also the aperture stop) of the system, and the resultant is impinged on the detector. A pair of image motion compensators is located as close to the exit pupil as possible for aligning off-axis inputs to the detector.

King, W. L.↗
NASA NTRS1990

IAL SPACE: A test laboratory for the ISO cryogenic payload

The ESA Infrared Space Observatory (ISO) satellite is a 3 axes pointed platform designed to make accurate pointed observations of astronomical objects and sources in the wavelength range between 2.5 and 200 microns. ISO is composed of a service module and a payload module which is a large cylindrical vacuum vessel. The vessel is in fact a cryostat (capacity of 2250 l of liquid He II) which contains the telescope and the four focal scientific instruments. The latter being cooled up to a temperature less than 4 K. The qualification of the payload requires the measurement respectively of: the image quality of the telescope through wave front error (WFE) measurements; and the optical alignment of the scientific instruments with respect to the telescope axis and the telescope focus, and this under cryogenic conditions. Consequently, since 1988, the FOCAL 5 IAL Space facility has been upgraded in order to perform the cryogenic optical tests of the ISO optical subsystems.

Cucchiaro, A.↗
NASA NTRS2000

Discrete and Diffuse Aurora During Varying Activity Levels: Simultaneous Fast and Polar UVI Observations

We examine simultaneous measurements of auroral electron precipitation obtained in-situ by the FAST spacecraft and remotely by Polar Ultraviolet Imagery (UVI) images for activity levels ranging from quiet to storm-time intervals. The incident energy flux measured by FAST and inferred from the UVI images agree well during quiescent periods, particularly in regions of discrete aurora in which the electron precipitation spectra are dominated by the component accelerated by a field-aligned potential. During magnetospheric substorms and active storm periods, such as those following Coronal Mass Ejection (CME) disturbances of the magnetosphere, the energy flux inferred from the UVI images generally exceeds that measured locally by FAST at the same location by as much as an order of magnitude. The auroral electrons during these active periods are dominated by diffuse precipitation which is observed up the to the highest energy channel of FAST (30 keV). These storm-time observations imply that a high energy component above 30 keV not observed by FAST may be contributing significantly to the total energy flux carried by the precipitating electrons. Observations suggest that as magnetospheric activity increases acceleration processes in the magnetosphere and pitch-angle diffusion by wave-particle interactions become more important than the ionospheric acceleration in producing the measured auroral energy fluxes.

Chua, D.↗
NASA NTRS2004

On-orbit performance testing of the Pointing Calibration & Reference Sensor for the Spitzer Space Telescope

We present the on-orbit performance results of the Pointing Calibration and Reference Sensor (PCRS) for the Spitzer Space Telescope. A cryogenic optical (center wavelength 0.55 mu) imager, the PCRS serves as the Observatory's fine guidance sensor by providing an alignment reference between the telescope boresight and the external spacecraft attitude determination system. The PCRS makes precision measurements of the positions of known guide stars; these are used to calibrate measurements from Spitzer's star tracker and gyroscopes to obtain the actual pointing of the Spitzer telescope. The PCRS calibrates out thermomoechanical drifts between the 300 K spacecraft bus and the 5.5 K telescope. By using only 16 pixels, the PCRS provides high precision centroiding with extremely low (`64 mu W) power dissipation, resulting in minimal impact to Spritzer's helium lifetime. We have demonstrated that the PCRS meets its centroiding accuracy requirement of 0.14 arcsec 1-sigma radial, which represents about1/100 pixel centroiding. The Spitzer Space Telescope was launched in 25 August, 2003 and completed its In-Orbit Checkout phase two months later; the PCRS has been operating failure free ever since.

Spitzer↗
NASA NTRS2012

The Astro-H Soft X-Ray Mirror

The Astro-H is led by the Japanese Space Agency (JAXA) in collaboration with many other institutions including the NASA Goddard Space Flight Center. Goddard's contributions include two soft X-ray telescopes (SXTs). The telescopes have an effective area of 562 square cm at 1 keV and 425 square cm at 6 keV with an image quality requirement of 1.7 arc-minutes half power diameter (HPD). The engineering model has demonstrated 1.1 arc-minutes HPD error. The design of the SXT is based on the successful Suzaku mission mirrors with some enhancements to improve the image quality. Two major enhancements are bonding the X-ray mirror foils to alignment bars instead of allowing the mirrors to float, and fabricating alignment bars with grooves within 5 microns of accuracy. An engineering model SXT was recently built and subjected to several tests including vibration, thermal, and X-ray performance in a beamline. Several lessons were learned during this testing that will be incorporated in the flight design. Test results and optical performance are discussed, along with a description of the design of the SXT.

Robinson, David↗
NASA NTRS2012

Cryogenic Photogrammetry and Radiometry for the James Webb Space Telescope Microshutters

The James Webb Space Telescope (JWST) relies on several innovations to complete its five year mission. One vital technology is microshutters, the programmable field selectors that enable the Near Infrared Spectrometer (NIRSpec) to perform multi-object spectroscopy. Mission success depends on acquiring spectra from large numbers of galaxies by positioning shutter slits over faint targets. Precise selection of faint targets requires field selectors that are both high in contrast and stable in position. We have developed test facilities to evaluate microshutter contrast and alignment stability at their 35K operating temperature. These facilities used a novel application of image registration algorithms to obtain non-contact, sub-micron measurements in cryogenic conditions. The cryogenic motion of the shutters was successfully characterized. Optical results also demonstrated that shutter contrast far exceeds the NIRSpec requirements. Our test program has concluded with the delivery of a flight-qualified field selection subsystem to the NIRSpec bench.

Chambers, Victor J.↗
NASA NTRS2018

LUVOIR Primary Mirror Segment Alignment Control With Joint Laser Metrology and Segment Edge Sensing

An approach is developed for the alignment and stability maintenance of the LUVOIR segmented primary mirror using a segment state estimation and wavefront control method based on a hybrid segment motion sensing architecture of laser truss metrology and segment edge sensors. Our current computer model was generated for LUVOIR Architecture Option A with a 15-meter aperture, 120segment primary mirror. The methodology and simulation results will be presented and analyzed. JPL has a long history of technology development in laser metrology and edge sensors, including work in SIM [7], Keck and TMT [8], CCAT [3] and LUVOIR [1]. We will discuss our current efforts of LUVOIR laser metrology and edge-sensor models development, showing sensitivities of sensor measurements to various mirror eigenmodes, removing global modes and strengthening weak modes by performing joint (hybrid) laser-metrology and edge sensing. We will define and derive an important performance metric called wavefront error multiplier (WEM), and show that WEM provides a simple link between sensor errors and the closed-loop (controlled) system wavefront error. We will show WEM values for several hybrid sensor configuration options studied. We will discuss an algorithm for mirror shape control and maintenance through segment state and wavefront estimations using joint edge-metrology sensing. We will compare simulated performance of mirror state estimation, wavefront estimation and wavefront control based on joint edge-metrology sensing among several sensor configurations, and show the impact of sensor error distributions on the segmented mirror alignment performance. Mirror shape control performance will be also be evaluated in terms of imaging contrast between inner working angles (IWA) and outer working angles (OWA) of a LUVOIR coronagraph. The research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. LUVOIR is a mission concept under study for the next astronomy Decadal Survey—the information presented in this paper is pre-decisional and is provided for planning and discussion purposes only.

Shelton, Chris↗
NASA NTRS2019

Technologies to Enable the Next Great Observatory

The Large Ultraviolet/Optical/Infrared Surveyor (LUVOIR) is one of four mission concepts being studied by NASA for the 2020 Decadal Survey in Astronomy and Astrophysics. LUVOIR will be capable of a broad range of science, including: direct imaging and characterization of a wide range of exoplanets and the search for biosignatures on Earth-like planets around sun-like stars; studying galaxy formation and evolution; investigating star and planet formation; and remote sensing of bodies within the Solar System. Enabling a mission as ambitious as LUVOIR requires an array of technologies, such as ultra-stable structures and optics, precision metrology and wavefront sensing, high-contrast imaging techniques, large-format detectors with very low noise, and high-throughput ultraviolet instrumentation. Critically, a systems-level approach must be taken to developing these technologies, guided by architecture studies to place each technology in the appropriate system context.In this poster, we describe LUVOIR's technology needs, as well as current efforts that are actively developing these technologies. We will discuss recent advancements in: measuring picometer-level displacements of optical and structural elements; sub-milli-kelvin thermal sensing and control; non-contact vibration isolation for pointing and dynamic stability; coronagraph design for achieving 10-10 contrast on a segmented system; high-speed metrology for optical system alignment; low-order and out-of-band wavefront sensing for maintaining high-contrast images; low-noise detectors across the ultraviolet, optical, and near infrared bands; broadband coatings with high-reflectivity below Ly. We will also describe a systems approach to coordinating the development of these technologies to achieve the necessary maturity for a LUVOIR mission start in the next decade.

space telescopes↗
DOE OSTI2026

CHESS 2025: Orthorectified airborne RGB imagery from NEON AOP surveys

This dataset provides Level 1 (L1) and Level 3 (L3) orthorectified Red-Green-Blue (RGB) imagery collected for the 2025 Colorado Headwaters Ecological Spectroscopy Study (CHESS). This high-resolution imagery is a photographic record of red, green, and blue visible light from sunlight reflected off of the Earth’s surface. The data comprise full-color images of the ground surface and are primarily intended to provide context to imaging spectroscopy and light detection and ranging (LiDAR) data. The data were acquired over three study domains in the Upper Gunnison river basin: the upper East River watershed (CRBU); Almont Triangle and Taylor Canyon (ALMO); and Upper Taylor River watershed (UPTA) between 2025-06-13 and 2025-07-15. RGB images were acquired using the PhaseOne IXM-RS150F high-resolution digital camera onboard the National Ecological Observatory Network (NEON) Airborne Observation Platform (AOP). The package data include both an L1 product comprising one camera frame per file and an L3 mosaic aligned to the Universal Transverse Mercator (UTM) Zone 13N grid and the World Geodetic System (WGS) 84 projection. Both products are provided in geotif (.tif) format at 0.1 m ground resolution. The bulk of the imagery was collected during the main CHESS field campaign from June 13 to July 15, 2025. Additional images of a portion of the Upper Taylor (UPTA) domain were collected on September 18, 2025, to fill gaps in imagery identified after the main campaign was complete. RGB camera imagery is not radiometrically calibrated, and therefore pixel values should not be exploited for scientific analysis. Pixel values have undergone a manual adjustment to enhance feature identification. The imagery is rigorously geolocated which does allow for reliable geometric information to be retrieved. To generate the orthorectified imagery, the NEON AOP camera captured visible spectrum in red, green, and blue bands. The raw images were then processed using NEON’s camera orthorectification workflow. A boresight calibration flight was made to build a complete camera, distortion, and alignment model. Color balance/white balance and exposure correction were applied to the raw RGB images. The corrected images were orthorectified by ray-tracing image pixels to a lidar-derived digital surface model (DSM) mesh using the refined camera model, outputting orthorectified raster pixels on a regular grid. Flightline-level data were mosaicked by selecting per-pixel contributions from overlapping orthorectified images using line-of-sight (LOS) zenith angle minimization to reduce edge distortions. CHESS Project Description: The Colorado Headwaters Ecological Spectroscopy Study (CHESS) comprised a multi-week airborne remote sensing and field observation campaign in the Upper Gunnison Basin, Colorado, conducted in June and July of 2025. Airborne remote sensing was conducted by the National Ecological Observatory Network Airborne Observation Platform (NEON AOP), concurrent with a field campaign run by the Rocky Mountain Biological Laboratory (RMBL), the Lawrence Berkeley National Laboratory (LBNL) and SLAC National Accelerator Laboratory Watershed Function Science Focus Area (SFA), and NASA-JPL (Jet Propulsion Laboratory) Earth Surface Mineral Dust Source Investigation (EMIT) program. Between June 10 and July 18, 2025, the NEON AOP flight team collected high-resolution aerial imaging spectroscopy and Light Detection and Ranging (LiDAR) data over three domains: the Upper East River (CRBU), Almont Triangle (ALMO), and the Upper Taylor Basin (UPTA). In coordination with the flights, a field campaign acquired ground-truth observations, including observations of vegetation composition, foliar traits, forest demography, and subsurface properties in 18 core sampling areas within the domains. Additional surface water observations were taken at over 380 point locations. All CHESS campaign datasets can be found within the CHESS ESS-DIVE data portal: https://data.ess-dive.lbl.gov/portals/chess. Funding Acknowledgement: Field and remote-sensing data acquisition was performed under a grant from the National Aeronautics and Space Administration (80NSSC24K1005). This work was also supported by the Watershed Function Science Focus Area at Lawrence Berkeley National Laboratory funded by the US Department of Energy, Office of Science, Biological and Environmental Research under Contract No. DE-AC02-05CH11231.

2018 NEON and 2025 CHESS Campaigns↗
NASA NTRS1988

On the relation between photospheric flow fields and the magnetic field distribution on the solar surface

Using the technique of local correlation tracking on a 28 minute time sequence of white-light images of solar granulation, the horizontal flow field on the solar surface is measured. The time series was obtained by the Solar Optical Universal Polarimeter (SOUP) on Spacelab 2 (Space Shuttle flight 51-F) and is free from atmospheric blurring and distortion. The SOUP flow fields have been compared with carefully aligned magnetograms taken over a nine hour period at the Big Bear Solar Observatory before, during, and after the SOUP images. The flow field and the magnetic field agree in considerable detail: vectors which define the flow of the white-light intensity pattern (granulation) point toward magnetic field regions, magnetic fields surround flow cells, and magnetic features move along the flow arrows. The projected locations of free particles ('corks') in the measured flow field congregate at the same locations where the magnetic field is observed.

Simon, George W.↗
NASA NTRS1979

Influence of alignment and surface defects on the performance of X-ray telescopes

The effects of misalignment and surface deformations on the image quality of a grazing incidence telescope with six nested subsystems are investigated. The axial rms-spot size serves as a measure for the image quality. The surface deformations are simulated by ellipsoidal and sinusoidal deviations from the ideal surface. Misalignments are tilts, decenters, and despaces of the individual elements. The effects of each type of defect are analyzed in a single two-element system. The full nested system is then analyzed in the presence of all possible defects on all 12 elements, whereby the magnitude of the defects is randomized within a given upper limit.

Korsch, D.↗
NASA NTRS1992

Optics Alignment Panel

The Optics Alignment Panel (OAP) was commissioned by the HST Science Working Group to determine the optimum alignment of the OTA optics. The goal was to find the position of the secondary mirror (SM) for which there is no coma or astigmatism in the camera images due to misaligned optics, either tilt or decenter. The despace position was reviewed of the SM and the optimum focus was sought. The results of these efforts are as follows: (1) the best estimate of the aligned position of the SM in the notation of HDOS is (DZ,DY,TZ,TY) = (+248 microns, +8 microns, +53 arcsec, -79 arcsec), and (2) the best focus, defined to be that despace which maximizes the fractional energy at 486 nm in a 0.1 arcsec radius of a stellar image, is 12.2 mm beyond paraxial focus. The data leading to these conclusions, and the estimated uncertainties in the final results, are presented.

Schroeder, Daniel J.↗
NASA NTRS2006

Phase Sensor for Aligning a Segmented Telescope Mirror

A phase sensor has been developed for use in aligning a segmented telescope mirror to within a fraction of a wavelength in piston. (As used here, piston signifies displacement of a mirror segment along the optical axis of the telescope.) Such precise alignment is necessary in order to realize the full benefit of the large aperture achievable through segmentation. This phase sensor is achromatic. It is based on two-wavelength shearing interferometry, and can be modified to utilize an extended or broad-band (e.g., white) light source. The sensor optics include a ruled diffraction grating and an imaging lens. The sensor can measure the piston shift between segments as well as aberrations of the segments. It can measure the surface error of an individual segment, making it possible to compensate for the error with optimal amount(s) of piston and/or tilt. The precise capture range of the sensor depends partly on the telescope design; the largest relative piston shifts measurable by use of this sensor are of the order of 100 m. The accuracy of the sensor also depends partly on the telescope design; in general, the accuracy is sufficient to enable alignment to within approximately half a wavelength. The interferometric image is digitized and processed by a simple algorithm in real time, and the output of the algorithm can be used to maintain alignment in real time, even in the presence of atmospheric turbulence. The sensor is robust. Through calibration, it can be made insensitive to (and, hence, tolerant of) misalignments and aberrations of its own optics, most aberrations of the telescope as a whole (in contradistinction to aberrations of individual segments), and most aberrations introduced by atmospheric turbulence

Stahl, Philip↗