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Results for “data reduction”

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 1,549 records · Page 86
All sourcesNASA NTRSDOE OSTI
NASA NTRS1967

Radiosonde data system.

Automatic radiosonde data processing system providing azimuth and elevation angles, temperature, humidity, etc

AUTOMATIC DATA PROCESSING SYSTEM↗
NASA NTRS1971

Reduction and analysis of magnetometer data from Mariners 4 and 5

In studies of data from the Mariner 4 and Mariner 5 magnetometers evidence has been found that during the flights, negative (toward the sun) polarity dominated at latitudes above the solar equatorial plane and positive polarity dominated at latitudes below this plane. A subsequent check of data taken with other spacecraft during 1964 through 1967 provided additional evidence of this effect. It is suggested that the dominant polarity of the interplanetary magnetic field follows the hemisphere-dependent dipolar field of the sun. Thus, the photospheric dipolar field may be an important source of the interplanetary magnetic field, especially at quiet times. It has also been found that, for an interplanetary magnetic field of a given polarity, the north-south component has a nonzero mean value in regions above and below the solar equatorial plane.

Source record↗
NASA NTRS1972

Preliminary results of OAO ultraviolet photoelectric photometry of galaxies

General results are presented based on nearly completed reductions of data for approximately 35 galaxies of all Hubble types. In general the visual and ultraviolet energy distributions are well correlated. The energy distribution in late-type galaxies appears to turn up sharply in the region around 2000 A, and this is tentatively interpreted as due to the presence of early-type stars whose energy distribution is modified by interstellar dust within these objects. Similar turnups may be present in several elliptical galaxies but the evidence at this time is not definitive.

Code, A. D.↗
NASA NTRS1971

Ultraviolet solar spectrum recorded by echelle spectrograph /1970 to 1800 A/.

Six spectrograms of the solar spectrum were obtained in the region from 1970 to 1800 A at a resolution of approximately 200,000 with a rocket-borne spectrograph using an echelle as the principal dispersing element. Reduction of data obtained has been completed in the region from 1946.5 to 1963.5 A, in which 79 absorption features are measured and 33 identified. Most of the identified stronger lines are due to Fe I. A significant feature of the solar spectrum in this region coincides with the raie ultime of Se I.

Mcallister, H. C.↗
NASA NTRS1975

Multi-mode optical sensor (B) evaluation test report

An evaluation test series was performed on the unit to develop realistic specifications for a similar device for use on the orbiter vehicle. Tests included sensitivity, target dynamic range, tracking angular rate, external magnetic field effects, and photocathode uniformity. Several demonstrations of operation under automatic control were also prepared, using a desk calculator for numerical control and for subsequent reduction of data derived from the test.

Smith, R. A.↗
NASA NTRS1977

Cost reduction potential of the DSN data base

The cost of the DSN data base can be reduced by computerizing and unifying the current multiplicity of separate manual, computer, and hybrid data bases. Savings would accrue from eliminating all manual system costs, increasing efficiency in data base implementation and maintenance-and-operation, and increasing data accuracy. By applying a simple mathematical savings model to current data base costs, this study estimates the probable range of net ten-year savings. The minimum net savings, under the assumptions of the study, are calculated as $7.5 million.

Mckenzie, M.↗
NASA NTRS1978

Short arc reduction of radar altimetry computer program

The Air Force Geophysics Laboratory computer program SARRA (Short Arc Reduction of Radar Altimetry) has been used for geoid determination with altimetric observations from the GEOS-3 satellite. An important feature of SARRA is the simultaneous recovery of the orbit parameters and the surface coefficients as defined by covariance function weights. Orbits good to approximately 20 meters are adequate for precise geoid determinations by virtue of the orbital adjustment in the reductions. Altimetric data over a portion of the North Atlantic Ocean have been processed to derive the regional geoid and gravity field. Analyses of altimeter residuals resulting from the short arc adjustment show that the residuals can be used to define the neglected higher order geoidal undulations with high fidelity and continuity.

Hadgigeorge, G.↗
NASA NTRS1977

Data handling for the geometric correction of large images

Several geometric distortions are present in remotely sensed images depending on the type of sensors and the object being observed. It is often desirable to compensate for these distortions and store the images in reference to a standard coordinate system. Digital techniques for correction are versatile and introduce a minimum of radiometric errors. The main problems to be considered in this area are the determination of the corrective transformation, resampling, and the management of the large quantities of data. It is shown that, by a judicious rearrangement of the input data, considerable reductions in the required memory capacity can be achieved. The rearrangement can be accomplished in several stages. The method presented here is amenable to pipeline implementation for processing a continuous stream of images.

Ramapriyan, H. K.↗