Search NASA⌕ Search

SEARCH · Search NASA

Results for “VISUAL OBSERVATION”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9

Ditching Investigation of a 1/14-Scale Model of the XC-123 Airplane

An investigation of a 1/14 scale dynamically similar model of the XC-123 airplane was made in calm water to observe the ditching behavior and to determine the safest procedure for making an emergency water landing, The behavior of the model was determined from motion-picture records, time-history deceleration records, and visual observations, Various scale-strength simulations were made to determine if the fuselage would be damaged and, if so, to determine the extent and location, It was concluded that the airplane should be ditched at a nose-high attitude of about 140 with the landing flaps down 45 deg., The airplane will probably make a porpoising run of about 415 feet (full scale) and the maximum longitudinal decelerations will be about 1 g, The fuselage bottom probably will be damaged and the fuselage will fill with water and sink to the wing level.

Fisher, Lloyd J.↗

Low-frequency passive-microwave observations of sea ice in the Weddell Sea

The microwave emission properties of first-year sea ice were investigated from the R/V Polarstern during the Antarctic Winter Weddell Gyre Project in 1989. Radiometer measurements were made at 611 MHz and 10 GHz and were accompanied by video and visual observations. Using the theory of radiometric emission from a layered medium, a method for deriving sea ice thickness from radiometer data is developed and tested. The model is based on an incoherent reflection process and predicts that the emissivity of saline ice increases monotonically with increasing ice thickness until saturation occurs.

Menashi, James D.↗

Uranus - The rings are black

An investigation is conducted concerning the possibility that the rings about Uranus discovered during the occultation of star SAO 158687 might have been observed in earlier studies of the planet. It is concluded that in view of a very low estimate for the contrast of the rings seen against the disk, a detection of the rings by earlier visual observers is unlikely. It appears, however, that the Stratoscope II photographs recorded the projection of the rings on the disk of Uranus.

Sinton, W. M.↗

Earth observations and photography experiment: Summary of significant results

Observation and photographic data from the Apollo Soyuz Test Project are analyzed. The discussion is structured according to the fields of investigation including: geology, desert studies, oceanography, hydrology, and meteorology. The data were obtained by: (1) visual observations of selected Earth features, (2) hand-held camera photography to document observations, and (3) stereo mapping photography of areas of significant scientific interest.

El-Baz, F.↗

Seeing Halley's Comet: A guide for observers in the Northern Hemisphere

A guide for the observation of Halley's comet is presented. The path of the comet is described for the fly by dates and charts are provided for location of the comet in the morning or evening skies. Suggestions for visual observation and photography of Halley's comet are included.

Source record↗

LDEF materials data analysis: Representative examples

Part of the philosophy which guided the examination of hardware from the Long Duration Exposure Facility (LDEF) was that materials present at multiple locations should have fairly high priority for investigation. Properties of such materials were characterized as a function of exposure conditions to obtain as much data as possible for predicting performance lifetimes. Results from examination of several materials from interior locations of LDEF, selected measurements on silverized teflon blanket specimens, and detailed measurements on the copper grounding strap from tray D11 are summarized. Visual observations of interior locations of LDEF made during deintegration at KSC showed apparent changes in particular specimens. This inspection lead to testing of selected nylon clamps, fiberglass shims, and heat shrink tubing from wire harness clamps, and visually discolored silver coated hex nuts.

Pippin, Gary↗

Successful Hybrid Approach to Visual and Video Observations of the 1999 Leonid Storm

A new hybrid technique of visual and video meteor observations is described. The method proved particularly effective for airborne observations of meteor shower activity. Results from the 1999 Leonid Multi-Instrument Aircraft Campaign are presented, and the profile shape of the 1999 Leonid storm is discussed in relation to meteor shower models. We find that the storm is best described with a Lorentz profile. Application to past meteor outbursts shows that the cui,rent multi-trailet model of a dust trail is slightly shifted and we crossed deeper into the 1899 epoch trallet than expected.

Jenniskens, Peter↗

Atmospheric environment for space shuttle (STS-33) launch

A summary is presented of selected atmospheric conditions observed near space shuttle STS-33 at launch time. STS-33 carried a DOD payload and the flight azimuth is denoted by a reference flight azimuth, since the actual flight azimuth is not known. Values of ambient pressure, temperature, moisture, ground winds, visual observations (clouds), and winds aloft are included. The sequence of pre-launch Jimsphere measured vertical wind profiles is given. The final atmospheric tape, which consists of wind and thermodynamic parameters versus altitude, for STS-33 vehicle ascent, was constructed. The STS-33 ascent atmospheric data tape was constructed by NASA-Marshall to provide an internally consistent data set for use in postflight performance assessments and represents the best estimates of the launch environment to the 400,000 ft altitude that was traversed by the STS-33 vehicle.

Jasper, G. L.↗

Atmospheric environment for space shuttle (STS-36) launch

A summary of selected atmospheric conditions observed near space shuttle STS-36 launch time on February 28, 1990, at Kennedy Space Center, Florida was presented. STS-36 carried a Department of Defense payload and the flight azimuth is not known. Values of ambient pressure, temperature, moisture, ground winds, visual observations (cloud), and winds aloft are included. The sequence of pre-launch Jimsphere-measured vertical wind profiles is given. The final atmospheric tape, which consists of wind and thermodynamic parameters versus altitude, for STS-36 vehicle ascent was constructed. The STS-36 ascent atmospheric data tape was constructed to provide an internally consistent data set for use in postflight performance assessments and represent the best estimate of the launch environment to the 400,000 feet altitude that was traversed by the STS-36 vehicle.

Jasper, G. L.↗

The application of an optical Fourier spectrum analyzer on detecting defects in mass-produced satellite photographs

Various defects in mass-produced pictures transmitted to earth from a satellite are investigated. It is found that the following defects are readily detectable via Fourier spectrum analysis: (1) bit slip, (2) breakup causing loss of image, and (3) disabled track at the top of the imagery. The scratches made on the film during mass production, which are difficult to detect by visual observation, also show themselves readily in Fourier spectrum analysis. A relation is established between the number of scratches, their width and depth and the intensity of their Fourier spectra. Other defects that are found to be equally suitable for Fourier spectrum analysis or visual (image analysis) detection are synchronous loss without blurring of image, and density variation in gray scale. However, the Fourier spectrum analysis is found to be unsuitable for detection of such defects as pin holes, annotation error, synchronous loss with blurring of images, and missing image in the beginning of the work order. The design of an automated, real time system, which will reject defective films, is treated.

Athale, R.↗

Reynolds-Averaged Navier-Stokes Simulations of Two Partial-Span Flap Wing Experiments

Structured Reynolds Averaged Navier-Stokes simulations of two partial-span flap wing experiments were performed. The high-lift aerodynamic and aeroacoustic wind-tunnel experiments were conducted at both the NASA Ames 7-by 10-Foot Wind Tunnel and at the NASA Langley Quiet Flow Facility. The purpose of these tests was to accurately document the acoustic and aerodynamic characteristics associated with the principle airframe noise sources, including flap side-edge noise. Specific measurements were taken that can be used to validate analytic and computational models of the noise sources and associated aerodynamic for configurations and conditions approximating flight for transport aircraft. The numerical results are used to both calibrate a widely used CFD code, CFL3D, and to obtain details of flap side-edge flow features not discernible from experimental observations. Both experimental set-ups were numerically modeled by using multiple block structured grids. Various turbulence models, grid block-interface interaction methods and grid topologies were implemented. Numerical results of both simulations are in excellent agreement with experimental measurements and flow visualization observations. The flow field in the flap-edge region was adequately resolved to discern some crucial information about the flow physics and to substantiate the merger of the two vortical structures. As a result of these investigations, airframe noise modelers have proposed various simplified models which use the results obtained from the steady-state computations as input.

Takalluk, M. A.↗

Summary of atmospheric data observations for 155 flight of MSFC/ABMA related aerospace vehicles

A summary of selected atmospheric conditions observed near launch time for 155 NASA-Marshall Space Flight Center and Army Ballistic Missile Agency related vehicles, launched primarilv from Cape Kennedy, Florida, between August 20, 1953, and November 16, 1963, is presented. Values of ambient pressure, temperature, relative humidity, ground winds, visual observations, density aloft, and wind/wind shear aloft are included. The extremes of these parameters are listed for each type of launch vehicle.

Johnson, D. L.↗

The infrared variability of the eruptive variable HM Sagittae

Recent near infrared observations have been obtained of the peculiar eruptive variable HM Sagittae which show a general decrease in the flux levels between 1 and 5 microns during 1977-1978. The existing data are yet too sparse to ascertain the nature of the variability; however, both the IR and visual observations confirm the close resemblance of HM Sge to V1016 Cyg. A model of a binary symbiotic system containing a late type variable may be consistent with the current data.

Slovak, M. H.↗

Atmospheric Environment for Space Shuttle (STS-28) Launch

A summary is presented of selected atmospheric conditions observed near Space Shuttle STS-28 launch time on August 8, 1989. STS-28 carried a Department of Defense payload and the flight azimuth is denoted by a reference flight azimuth, since the actual flight azimuth is not known. Values of ambient pressure, temperature, moisture, ground winds, visual observations (cloud), and winds aloft are included. The sequence of prelaunch Jimsphere-measured vertical wind profiles is given. The final atmospheric tape, which consists of wind and thermodynamic parameters versus altitude, for STS-28 vehicle ascent was constructed and represents the best estimate of the launch environment to 400,000 ft altitude that was traversed by the STS-28 vehicle. The STS-28 ascent atmospheric data tape was constructed by Marshall Space Flight Center's Earth Science and Applications Division to provide an internally consistent data set for use in post-flight performance assessments.

Jasper, G. L.↗

Temporal and vertical distribution of acidity and ionic composition in clouds - Comparison between modeling results and observations

Cyclic temporal variations of pH and ionic concentration in sampled clouds which traversed the Mt. Mitchell State Park (North Carolina) site during the summers of 1986, 1987, and 1988 are reported. These clouds typically had a measured pH minimum during their initial and final stages. The cause of this basic cylic pattern is attributed to sampling at different vertical levels of the cloud. This is substantiated by visual observations made while sampling. The results also suggest that the measured pH patterns do not always exhibit minima during the formative and dissipative stages of the cloud, apparently in response to the underlying dynamical processes. The relationship between temporal pH measurements made at a stationary site to vertical cloud levels provides insights into the physical processes (e.g., nucleation scavenging near cloud base, dry air entrainment near cloud top) influencing the observed cloud-water chemistry on a real-time basis and would improve cloud chemistry models.

Defelice, T. P.↗

Earth observations during Space Shuttle mission STS-34 - 18-23 October 1989

An overview is presented of the 31st Space Shuttle mission, whose major objective was to deploy the Galileo spacecraft. Color images are presented of photos taken by the four videocameras in the payload bay, one 16-mm Arriflex in the cabin, a videocamcorder, three 35 mm cameras, two 70 mm cameras, and an IMAX camera. In addition, descriptions of visual observations by the mission astronauts are given. The most significant STS-34 earth photography for the major geographical regions is discussed. Individual highlights of this mission include observation of the apparent recovery of the water level of Lake Nasser to conditions similar to those during the second Space Shuttle mission of 1981; the documentation of the impact of the Yucatan forest blowdown and fires after the passage of Hurricane Gilbert; and the confirmation of the high value of space photography under low and very low sun angle conditions for geomorphological and geological analyses.

Helfert, Michael R.↗

3D Orbit Visualization for Earth-Observing Missions

This software visualizes orbit paths for the Orbiting Carbon Observatory (OCO), but was designed to be general and applicable to any Earth-observing mission. The software uses the Google Earth user interface to provide a visual mechanism to explore spacecraft orbit paths, ground footprint locations, and local cloud cover conditions. In addition, a drill-down capability allows for users to point and click on a particular observation frame to pop up ancillary information such as data product filenames and directory paths, latitude, longitude, time stamp, column-average dry air mole fraction of carbon dioxide, and solar zenith angle. This software can be integrated with the ground data system for any Earth-observing mission to automatically generate daily orbit path data products in Google Earth KML format. These KML data products can be directly loaded into the Google Earth application for interactive 3D visualization of the orbit paths for each mission day. Each time the application runs, the daily orbit paths are encapsulated in a KML file for each mission day since the last time the application ran. Alternatively, the daily KML for a specified mission day may be generated. The application automatically extracts the spacecraft position and ground footprint geometry as a function of time from a daily Level 1B data product created and archived by the mission s ground data system software. In addition, ancillary data, such as the column-averaged dry air mole fraction of carbon dioxide and solar zenith angle, are automatically extracted from a Level 2 mission data product. Zoom, pan, and rotate capability are provided through the standard Google Earth interface. Cloud cover is indicated with an image layer from the MODIS (Moderate Resolution Imaging Spectroradiometer) aboard the Aqua satellite, which is automatically retrieved from JPL s OnEarth Web service.

Jacob, Joseph C.↗

Infrared observations of RS CVn stars

The paper presents infrared photometry of the RS CVn binary stars AR Lac (1.2-10 microns) and MM Her (1.2-3.5 microns) as they egressed from their primary and secondary eclipses; of the eclipsing systems RS CVn and Z Her at maximum light (1.2-10 microns) and of the non-eclipsing systems UX Ari and HR 1099 (1.2-10 microns). An analysis of these and published V data based on flux ratio diagrams (linear analogues of color-color diagrams) shows that G and K stars supply the infrared light of these systems. In AR Lac, the combined light of a G5-K0 subgiant and either a late F dwarf or an early F subgiant can account for the observed visual and infrared light curves. None of these systems shows infrared emission from circumstellar matter. This result is simply understood: dust grains would not be expected to form in the physical conditions surrounding the subgiant, and the corona and chromosphere (whose properties have been deduced from spectroscopic X-ray observations) should not produce appreciable infrared emission.

Berriman, G.↗