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Hudson, R. D.

Publications and source records attributed to Hudson, R. D..

44 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1976

The O(3P) and N(4S) density measurement at 225 km by ultraviolet absorption and fluorescence in the Apollo-Soyuz test project

The densities of O(3P) and N(4S) at 225 km were determined during the Apollo Soyuz Test Project by a resonance absorption/fluorescence technique in which OI and NI line radiation produced and collimated on board the Apollo was reflected from the Soyuz back to the Apollo for spectral analysis. The two spacecraft maneuvered so that a range of observation angles of plus or minus 15 deg with respect to the normal to the orbital velocity vector was scanned. The measurements were made at night on two consecutive orbits at spacecraft separations of 150 and 500 m. The resulting relative counting rates as function of observation angle were compared to calculated values to determine the oxygen value. This value agrees with mass spectrometric measurements made under similar conditions. The nitrogen value is in good agreement with other measurements and suggests a smaller diurnal variation than is predicted by present models.

Kaufman, F.↗
NASA NTRS1974

Absorption cross sections of stratospheric molecules

Two classes of molecular species must be considered in a calculation of photochemical rates in the stratosphere. The first class consists of molecular oxygen and ozone, while the second class contains the remainder of the minor constituents. If accurate values of the transmitted fluxes are required at large optical depths, the cross sections for molecular oxygen and ozone must be known to within a few per cent at least. On the other hand, the photochemical rates for the minor species are given simply by the relevant cross sections. A review of published cross sections is presented, giving attention to molecular oxygen, ozone, nitric oxide, nitrogen dioxide, nitrous oxide, nitric acid, ammonia, water vapor, hydrogen peroxide, carbon monoxide, carbon dioxide, and sulfur dioxide.

Hudson, R. D.↗
NASA NTRS1973

Atmospheric studies payloads

Several proposed Shuttle payloads for studying atmospheric phenomena and structure are discussed, with particular reference to a concept being developed for an optical facility. The payloads are put together of instruments both for in-situ measurements and for remote sensing of atmospheric emission, scattering, and absorption, using active and passive optical elements. Studies may include the artificial perturbation of the upper atmosphere with vapor releases or high powered UV lasers. The major areas of research in atmospheric physics are outlined, along with the parameters and phenomena of interest and the measurement techniques most frequently employed.

Hudson, R. D.↗
NASA NTRS1972

Photodissociation rates of molecular oxygen in the mesosphere and lower thermosphere.

Use of recently obtained band oscillator strengths and predissociation line widths, for the Schumann-Runge band system to calculate the photodissociation rate of molecular oxygen as a function of column density and temperature by solar radiation between 1025 and 2500 A. Data are presented from which the mean transmission and photodissociation rates for given wavelength intervals between 1750 and 2025 A can be calculated for column densities between 10 to the 17th and 10 to the 23rd molecules/sq cm and for temperatures between 150 and 300 K. Also, the production of vibrationally excited oxygen molecules as a result of fluorescence in the Schumann-Runge bands is discussed.

Hudson, R. D.↗
NASA NTRS1972

Interpolation constants for calculation of transmittance and rate of dissociation of molecular oxygen in the mesosphere and lower thermosphere

Values of band oscillator strengths and rotational line widths for the Schumann-Runge band system have been used to derive interpolation constants from which the transmittance and rate of dissociation of molecular oxygen can be calculated. These constants, valid for temperatures between 150 and 300 K and for column densities between 1 x 10 to the 17th power/cm sq and 7 x 10 to the 24th power/cm sq, cover the wavelength range 1750 and 2050A.

Hudson, R. D.↗
NASA NTRS1970

Bibliography of photoabsorption cross-section data

This bibliography contains only references which report a measured or calculated photoabsorption cross section (relative or normalized) in regions of continuous absorption. The bibliography is current as of January 1, 1970.

Hudson, R. D.↗