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Results for “radiation waves”

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 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1994

Possibility to sound the atmospheric ozone by a radiosonde equipped with two temperature sensors, sensitive and non-sensitive to the long wave radiation

The sensitiveness of white coated thermistor sensors and non-sensitiveness of the gold coated over white thermistor sensors (which have been manufactured by a vacuum evaporation process) to long wave radiation were ascertained by some simple experiments in-room and also by analyses of some results of experimental soundings. From results of analyses on the temperature discrepancies caused by long wave radiation, the possibility to sound the atmospheric ozone partial pressure by a radiosonde equipped with two kinds of sensors, sensitive and non-sensitive to the long wave radiation was suggested, and the test results of the newly developed software for the deduction of ozone partial pressure in upper layers was also shown. However, it was found that the following is the necessary condition to realize the purpose. The sounding should be made by a radiosonde equipped with three sensors, instead of two, one being non-sensitive to the long wave radiation perfectly, and the other two also non-sensitive partially to the downward one, with two different angles of exposure upward. It is essential for the realization of the purpose to get two different values of temperature discrepancies simultaneously observed by the three sensors mentioned above and to avoid the troublesome effects of the upward long wave radiation.

Kitaoka, T.↗
NASA NTRS1989

The space microwave interferometer and the search for cosmic background gravitational wave radiation

Present and planned investigations which use interplanetary spacecraft for gravitational wave searches are severely limited in their detection capability. This limitation has to do both with the Earth-based tracking procedures used and with the configuration of the experiments themselves. It is suggested that a much improved experiment can now be made using a multiarm interferometer designed with current operating elements. An important source of gravitational wave radiation, the cosmic background, may well be within reach of detection with these procedures. It is proposed to make a number of experimental steps that can now be carried out using TDRSS spacecraft and would conclude in the establishment of an operating multiarm microwave interferometer. This interferometer is projected to have a sensitivity to cosmic background gravitational wave radiation with an energy of less than 10(exp -4) cosmic closure density and to periodic waves generating spatial strain approaching 10(exp -19) in the range 0.1 to 0.001 Hz.

Anderson, Allen Joel↗
NASA NTRS1991

Global precipitation estimates from satellite - Using difference fields of outgoing long-wave radiation

Global precipitation estimates using satellite data are derived using difference fields of outgoing long-wave radiation (OLR). The difference fields consist of clear OLR minus cloudy OLR, which is a measure of long-wave cloud radiative forcing at the top of the earth-atmosphere system; and clear daytime OLR minus clear night-time OLR, which is a measure of the diurnal variation of surface heating. All geophysical parameters used to compute OLR are derived from an analysis of the HIRS2/MSU sounding data. The derived global precipitation estimates show good agreement with collocated raingage data over land.

Wu, Man-Li↗
NASA NTRS1990

Outgoing long-wave radiation computed from HIRS2/MSU soundings

Fields of outgoing long-wave radiation (OLR) have been computed using geophysical parameters retrieved from analysis of HIRS2/MSU sounding data as input to a modified version of the Wu-Kaplan radiation code used in the Goddard Laboratory for Atmospheres fourth-order general circulation model. Monthly mean results for 1979 agree with monthly mean OLR fields measured by the Nimbus 7 earth radiation budget (ERB) broadband narrow field of view instrument within standard deviations of 6.3 W/sq m but with a global mean bias of 8.0 W/sq m. Results are shown for July 1979. The areas of disagreement between high-resolution infrared radiation sounder OLR and ERB OLR are small but spatially coherent with patterns which may be related to sampling differences. The difference patterns are much less extensive than those between OLR derived from advanced very high resolution radiometer 11-micron observations and ERB OLR.

Wu, Man-Li C.↗
NASA NTRS1985

Preionization-dependent families of radiative shock waves

Radiation shock waves are shown to be organizable into families within which the spectra are very similar. A high-velocity shock into neutral material is spectrally similar to a somewhat slower shock in fully ionized material. The similarities should allow the identification of the family to which an observed spectrum belongs, while spectral details permit subsequent identification of the separate values of shock velocity and preionization. By calculating shock spectra for the various families at constant recombination zone density, rather than constant preshock density, it is possible to separate the effects of 'velocity' (by which is meant postionization enthalpy per atom) from those of 'density' (by which is meant the degree of collisional deexcitation in the optical lines).

Cox, D. P.↗
NASA NTRS1984

Auroral kilometric radiation: Wave modes, harmonic and source region electron density structures

A change from extraordinary (X) mode to ordinary (0) mode dominance is observed in the auroral kilometric radiation (AKR) detected on ISIS 1 topside sounder ionograms as the source region plasma to gyrofrequency ratio fN/fH varies from 0.1 to 1.3. The X and 0 mode AKR, Z (the slow branch of the X mode) and whistler (W) mode are also observed. The Z mode is typically slightly less intense than the 0-mode. Thw W-mode is confined to frequencies less than fH/2, suggesting that it is the result of field aligned ducted signals reaching the satellite from a source at lower altitudes. Harmonic AKR bands are commonly observed and the 2nd harmonic appears to be due to propagating signals. The deduced (fN/fH) at the bottom of the AKR source region is always less than 0.4 and is typically less than 0.2 during the generation of X-mode AKR, but approaches 0.9 for 0-mode AKR. No large density enhancements were observed within AKR source region density cavities. It is suggested that the observed INTENSE AKR IS cyclotron X-mode radiation rather than plasma frequency 0-mode radiation.

Benson, R. F.↗
NASA NTRS1985

Auroral kilometric radiation - Wave modes, harmonics, and source region electron density structures

A change from extraordinary (X) mode to ordinary (O) mode dominance is observed in the auroral kilometric radiation (AKR) detected on ISIS 1 topside sounder ionograms as the source region plasma to gyrofrequency ratio fN/fH varies from 0.1 to 1.3. The X and O mode AKR, Z (the slow branch of the X mode) and whistler (W) mode are also observed. The Z mode is typically slightly less intense than the O-mode. The W-mode is confined to frequencies less than fH/2, suggesting that it is the result of field aligned ducted signals reaching the satellite from a source at lower altitudes. Harmonic AKR bands are commonly observed and the 2nd harmonic appears to be due to propagating signals. The deduced (fN/fH) at the bottom of the AKR source region is always less than 0.4 and is typically less than 0.2 during the generation of X-mode AKR, but approaches 0.9 for O-mode AKR. No large density enhancements were observed within AKR source region density cavities. It is suggested that the observed intense AKR is cyclotron X-mode radiation rather than plasma frequency O-mode radiation.

Benson, R. F.↗
NASA NTRS1982

Laboratory simulation of pelagic asteroidal impact Atmospheric injection, benthic topography, and the surface wave radiation field

The hypervelocity impact (1.25-6 km/s) of projectiles into water overlying unconsolidated strata is reported for a variety of water depths. Variation of the background atmospheric pressure is found to be an important additional parameter. The relation of these exploratory experiments to pelagic impact of asteroidal-sized objects is discussed from the standpoint of atmospheric injection of sea water, the modification of bottom (benthic) topography, and the generation of a field of mega-amplitude sea waves and their propagation away from the source.

Gault, D. E.↗