Window aberration correction in laser velocimetry using multifaceted holographic optical elements
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Schock, H. J.↗
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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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Bioengineering and Rehabilitation: Windows of Opportunity Past, Present and Future
The applications of NASA research in the areas of bioengineering and rehabilitation are discussed. Wheelchairs, gait analysis, blood analyzers, programmable pacemakers and cardiology mannequins are among the topics covered.
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Experimental evidence for spring and autumn windows for the detection of geobotanical anomalies through the remote sensing of overlying vegetation
It is pointed out that in many regions of the world, vegetation is the predominant factor influencing variation in reflected energy in the 0.4-2.5 micron region of the spectrum. Studies have, therefore, been conducted regarding the utility of remote sensing for detecting changes in vegetation which could be related to the presence of mineralization. The present paper provides primarily a report on the results of the second year of a multiyear study of geobotanical-remote-sensing relationships as developed over areas of sulfide mineralization. The field study has a strong experimental design basis. It is proceeded by first delineating the boundaries of a large geographic region which satisfied a set of previously enumerated field-site criteria. Within this region, carefully selected pairs of mineralized and nonmineralized test sites were examined over the growing season. The experiment is to provide information about the spectral and temporal resolutions required for remote-sensing-geobotanical exploration. The obtained results are evaluated.
Labovitz, M. L.↗
Office automation: The administrative window into the integrated DBMS
In parallel to the evolution of Management Information Systems from simple data files to complex data bases, the stand-alone computer systems have been migrating toward fully integrated systems serving the work force. The next major productivity gain may very well be to make these highly sophisticated working level Data Base Management Systems (DMBS) serve all levels of management with reports of varying levels of detail. Most attempts by the DBMS development organization to provide useful information to management seem to bog down in the quagmire of competing working level requirements. Most large DBMS development organizations possess three to five year backlogs. Perhaps Office Automation is the vehicle that brings to pass the Management Information System that really serves management. A good office automation system manned by a team of facilitators seeking opportunities to serve end-users could go a long way toward defining a DBMS that serves management. This paper will briefly discuss the problems of the DBMS organization, alternative approaches to solving some of the major problems, a debate about problems that may have no solution, and finally how office automation fits into the development of the Manager's Management Information System.
Brock, G. H.↗
Cognitive and perceptual principles of window-based computer dialogues
The information-space flyer concept is similar to a flight simulator where one traverses over information topology (such as a sematic network) rather than a geographical terrain. Research and software engineering are discussed. Also included is a user manual.
Pavel, M.↗
A spring window for geobotanical anomaly detection
The observation of senescence of deciduous vegetation to detect soil heavy metal mineralization is discussed. A gridded sampling of two sites of Quercus alba L. in south-central Virginia in 1982 is studied. The data reveal that smaller leaf blade lengths are observed in the soil site with copper, lead, and zinc concentrations. A random study in 1983 of red and white Q. rubra L., Q. prinus L., and Acer rubrum L., to confirm previous results is described. The observations of blade length and bud breaks show a 7-10 day lag in growth in the mineral site for the oak trees; however, the maple trees are not influenced by the minerals.
Bell, R.↗
Field Repair Of Thermoplastic Windows And Canopies
Toroid bonding techniques further developed to meet typical field-repair requirements. Induction-heating power supply engineered into "ruggedized" solid-state unit, in a 1-ft to the third power package weighing 20 lb. Hand-held bonding gun weighing 3 lb plugs into this power supply on long cord. Maximum power required is 300 W. Lightly loaded repair bonds made in several minutes at average power input of 150 W on metallic, polymeric, or polymermatrix materials.
Fox, Robert L.↗
Efficient Ada multitasking on a RISC register window architecture
This work addresses the problem of reducing context switch overhead on a processor which supports a large register file - a register file much like that which is part of the Berkeley RISC processors and several other emerging architectures (which are not necessarily reduced instruction set machines in the purest sense). Such a reduction in overhead is particularly desirable in a real-time embedded application, in which task-to-task context switch overhead may result in failure to meet crucial deadlines. A storage management technique by which a context switch may be implemented as cheaply as a procedure call is presented. The essence of this technique is the avoidance of the save/restore of registers on the context switch. This is achieved through analysis of the static source text of an Ada tasking program. Information gained during that analysis directs the optimized storage management strategy for that program at run time. A formal verification of the technique in terms of an operational control model and an evaluation of the technique's performance via simulations driven by synthetic Ada program traces are presented.
Kearns, J. P.↗
The atmosphere as a research window - Signal or noise
The interpretation of measurements by instruments with FOV that are large enough to contain pronounced radiometric variations is discussed, focusing on the retrieval of cloud properties from satellite radiance measurements. Examples are presented for three retrieval approaches. The use of a physical principle to establish a relationship between the measurement and the desired parameter is shown for cirrus-cloud optical depth and precipitation from passive microwave measurements. Examples of the use of inherent variability of the atmosphere and the statistical character of this variability are the spatial covariance method and the threshold method. Also, two examples using a hybrid of these two methods are presented. It is shown that the natural variability (noise) within the instrument FOV biases the relationship between the measurement and the parameter of interest which would be predicted by simple one-dimensional radiative-transfer theory. It is suggested that the noise of the measurement also contains signal, forming the basis for hybrid methods.
Stephens, Graeme L.↗
Determination of low-level precipitable water variability from split window channel radiance data
A technique has been developed for the quantitative definition of low-level precipitable water vapor from radiance measurements. High resolution data from the airborne Multispectral Atmospheric Mapping Sensor (MAMS) have been used in conjunction with this technique to define variability down to the lower end of the mesoscale. MAMS measures reflected radiation from the earth's surface and clouds in eight visible bands, and thermal emission from the earth's surface, clouds, and atmospheric water vapor in three IR bands. The present technique is found to be applicable to existing satellite sensors, but will not yield the mesoscale resolution furnished by the aircraft data.
Jedlovec, Gary J.↗
Acoustic transmissibility of advanced turboprop aircraft windows
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Grosveld, Ferdinand W.↗
Validation of AVHRR split window skin temperature retrievals for estimating tropospheric infrared cooling over the Tibetan Plateau
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Smith, Eric A.↗
Apollo 15 regolith breccias - Window to a KREEP regolith
The characteristics of 28 regolith breccias returned from the Apollo 15 site have been compared with those of Apollo 15 soils, Apollo 15 rock types, and Apollo 16 regolith breccias. The results suggest that KREEP basalts are not exotic to the site, and that the site is underlain by KREEP basalts which were converted to a KREEP-rich regolith full of small KREEP basalt fragments and KREEP composition glass. A possible implication of the present model is that agglutinate production was not significant in the time interval from 3.9-3.3 Gy.
Mckay, D. S.↗
Late emission from supernovae - A window on stellar nucleosynthesis
Monte Carlo techniques are used to study the energy deposition of gamma rays from the radioactive decay of Co-56 in Type Ib and Type II SN. It is found that above an electron fraction of about 0.1, direct excitations are negligible, and the line emission arises from thermal processes. The results indicate that the emission is dominated by neutral and singly ionized lines, including forbiden O I, forbidden Ca II, forbidden C I, and forbidden Si I. The late spectrum is shown to be useful as a diagnostic of the nucleosynthetic structure of the ejecta. The present model has been applied to observations of the Type Ib SN 1985F, and it is suggested that Type Ib SN come from stars of greater than 25 solar masses.
Fransson, Claes↗
Launch window expansion and trajectory correction strategies prior to the first lunar swingby
Double lunar swing-by (DLSB) orbits will be employed by 'Geotail' and other spacecraft in the International Solar Terrestrial Physics program in order to conduct observations in the geomagnetic tail and front field regions of the earth begining in 1992. For these missions, first swing-by dates are virtually fixed due to the dependency of the inertial frame apsis direction on them; in addition, the relative velocity magnitude to the moon is defined so that the DLSB condition will hold rigorously. These two conditions entail that the spacecraft intercept the moon on the prescribed dates. Several revolutions in intermediate transfer orbits are required prior to the first swing-by, in order to adjust flight time while maintaining the requisite lunar swing-by date.
Engel, Cheryl↗
Constant propellant use rendezvous scenario across a launch window for refueling missions
Active rendezvous of an unmanned spacecraft with the Space Transportation System (STS) Shuttle for refueling missions is investigated. The operational constraints facing both the maneuvering spacecraft and the Shuttle during a rendezvous sequence are presented. For example, the user spacecraft must arrive in the generic Shuttle control box at a specified time after Shuttle launch. In addition, the spacecraft must be able to initiate the transfer sequence from any point in its orbit. The standard four-burn rendezvous sequence, consisting of two Hohmann transfers and an intermediate phasing orbit, is presented as a low-energy solution for rendezvous and retrieval missions. However, for refueling missions, the Shuttle must completely refuel the spacecraft and return to Earth with no excess fuel. This additional constraint is not satisfied by the standard four-burn sequence. Therefore, a variation of the four-burn rendezvous, the constant delta-V scenario, was developed to satisfy the added requirement.
Hametz, M. E.↗
Precipitable water estimation from high-resolution split window radiance measurements
A technique that uses the spatial variance of image brightness temperature to derive total column precipitable water is applied to high-resolution multispectral aircraft scanner data for the June 19, 1986 COHMEX day. The technique has several advantages over other approaches in that it requires only relative calibration accuracy, is less susceptible to instrument error, and does not directly use a priori information. Results indicate significant horizontal variability of precipitable water at the mesoscale. Precipitable water gradients of 6 mm per 10 km are not uncommon. The results verify well against special rawinsonde measurements and the ensuing cloud field development. While only applied to this specialized aircraft data, the applicability of the technique to operational AVHRR and VAS data is discussed.
Jedlovec, Gary J.↗
The 27-28 October 1986 FIRE IFO cirrus case study - Spectral properties of cirrus clouds in the 8-12 micron window
Lidar and radiometric observations are employed for detecting the presence of cirrus and describing their radiative properties. The study focuses on observations of the radiative properties of cirrus clouds within the 8-12 micron spectral region. The instrumentation that achieved the spectral radiance observations used in this study is described. Results are presented for October 28, 1986 FIRE case study day in terms of brightness temperature differences, cirrus effective emissivities, and the gross microphysical characteristics of the observed clouds. The HIS and lidar observations were combined to derive the spectral effective beam emissivity of the cirrus clouds. Fifty percent of clouds on this day displayed a spectral variation of effective beam emissivity from 2-10 percent. These differences, in conjunction with large differences in the HIS observed brightness temperatures, indicate that cirrus clouds cannot be considered gray in the 8-12 micron region. Also, the derived spectral transmittance of the cloud is used to infer the effective radii of the particle size distribution.
Ackerman, Steven A.↗