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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 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS1969

Particle shadowing by the moon.

Moon effect on intensity and angular distribution of energetic electron and proton shadowing as observed by Explorer satellites

Ness, N. F.↗
NASA NTRS1971

Computer program for thermal analysis of shadow shields in a vacuum

Computer program determines temperature profiles and heat transfer rates for shadow shielded cryogenic tank. Tank, shields, and thermal radiation heat source are all axisymmetric. Thermal analysis considers varying shield and tank temperatures, surface properties, and geometric arrangements. Similar heat source properties are also considered.

Boyle, R. J.↗
NASA NTRS1971

The shadow band phenomenon

Shadow band phenomenon observed during solar eclipses and visible only minutes preceeding and following totality

Daly, C. J.↗
NASA NTRS1971

The shadow band phenomenon

Shadow band observations during 7 March 1970 solar eclipse, determining spectral energy distribution from magnetic tape recordings of collimated photocells output

Daly, C. J.↗
NASA NTRS1973

Prevention of damage to the science instruments of Mariner-Mars '71 spacecraft due to accidental viewing of the sun during sun-acquisition following exit from earth shadow.

It is pointed out that severe damage could result to the shutters of several science instruments if the sun were to appear in or sweep across the field of view at any time during the mission to Mars in 1971. The problem of accidental viewing of the sun following exit from the earth's shadow is probabilistic and rather difficult to resolve. The studies conducted show that typical probabilities of TV-A viewing the sun are on the order of 0.1%.

Mukhopadhyay, A. K.↗
NASA NTRS1974

Multiple-slit shadow device for sensing the direction to a shining object

A multi-slit shadow direction sensor of jalousie type (JDS) was developed to provide a simple, highly reliable tracking system to guide a rotating mirror toward the sun so that the reflected light would illuminate the input slit of a photoelectric spectrometer. The operating principle and stability are considered as well as determination of initial signal level at the output of each photosensor. A procedure is recommended for calculation of a JDS. Both one- and two-coordinate sun direction sensors are described and considered for use in the tracking system of a photoelectric spectrometer.

Bruns, A. V.↗
NASA NTRS1974

Lunar particle shadows and boundary layer experiment: Plasma and energetic particles on the Apollo 15 and 16 subsatellites

The lunar particle shadows and boundary layer experiments aboard the Apollo 15 and 16 subsatellites and scientific reduction and analysis of the data to date are discussed with emphasis on four major topics: solar particles; interplanetry particle phenomena; lunar interactions; and topology and dynamics of the magnetosphere at lunar orbit. The studies of solar and interplanetary particles concentrated on the low energy region which was essentially unexplored, and the studies of lunar interaction pointed up the transition from single particle to plasma characteristics. The analysis concentrated on the electron angular distributions as highly sensitive indicators of localized magnetization of the lunar surface. Magnetosphere experiments provided the first electric field measurements in the distant magnetotail, as well as comprehensive low energy particle measurements at lunar distance.

Anderson, K. A.↗
NASA NTRS1975

A general non-parametric classifier applied to discriminating surface water from terrain shadows

A general non-parametric classifier is described in the context of discriminating surface water from terrain shadows. In addition to using non-parametric statistics, this classifier permits the use of a cost matrix to assign different penalties to various types of misclassifications. The approach also differs from conventional classifiers in that it applies the maximum-likelihood criterion to overall class probabilities as opposed to the standard practice of choosing the most likely individual subclass. The classifier performance is evaluated using two different effectiveness measures for a specific set of ERTS data.

Eppler, W. G.↗