Determination of band oscillator strengths of atmospheric molecules from high resolution vacuum ultraviolet cross section measurements

An account is given of progress during the six month period 1/11/84 to 4/30/85 in work on: (1) rovibronic assignments of the Schumann-Runge bands of O2-18; and (2) optical depth measurements of the Schumann-Runge bands of O2-18. The work summarized above is part of a comprehensive spectroscopic investigation of the absorption wavelengths, rotational line assignments, cross sections, and band oscillator strengths of the Schumann-Runge bands of O2-18 and O-18 O-16 in the wavelength region 175-205 nm. The investigation is conducted at high resolution with a 6.65 m scanning spectrometer/spectrograph which is, by reason of its small instrumental width (FWHM = 0.0013 nm), uniquely suitable for cross section measurements of molecular bands with discrete rotational structure. Absolute cross sections, which are independent of the instrumental function and from which band oscillator strengths are directly determined, will be measured for the absorption bands that are most predissociated

Instrumentation and flight performance of HCO high resolution wavelength spectrometer - NASA Aerobee flight 4.185 US

Flight performance of high resolution spectrometer in Aerobee rocket vehicl

NAVSTAR: Global positioning system an evolutionary research and development program

A description is given of NAVSTAR and the conception validation program for the system. System compatibility and performance projections are discussed

The application of NAVSTAR Differential GPS to civil helicopter operations

Principles concerning the operation of the NAVSTAR Global Positioning Systems (GPS) are discussed. Selective availability issues concerning NAVSTAR GPS and differential GPS concepts are analyzed. Civil support and market potential for differential GPS are outlined. It is concluded that differential GPS provides a variation on the baseline GPS system, and gives an assured, uninterrupted level of accuracy for the civilian community

Computer assisted performance tests of the Lyman Alpha Coronagraph

Preflight calibration and performance tests of the Lyman Alpha Coronagraph rocket instrument in the laboratory, with the experiment in its flight configuration and illumination levels near those expected during flight were successfully carried out using a pulse code modulation telemetry system simulator interfaced in real time to a PDP 11/10 computer system. Post acquisition data reduction programs developed and implemented on the same computer system aided in the interpretation of test and calibration data

The calculated effect of trailing-edge flaps on the take-off of flying boats

The results of take-off calculations are given for an application of simple trailing-edge flaps to two hypothetical flying boats, one having medium wing and power loading and consequently considerable excess of thrust over total resistance during the take-off run, the other having high wing and power loading and a very low excess thrust. For these seaplanes the effect of downward flap settings was: (1) to increase the total resistance below the stalling speed, (2) to decrease the get-away speed, (3) to improve the take-off performance of the seaplane having considerable excess thrust, and (4) to hinder the take-off of the seaplane having low excess thrust. It is indicated that flaps would allow a decrease in the high angles of wing setting necessary with most seaplanes, provided that the excess thrust is not too low

Lyman alpha coronagraph research sounding rocket program

The ultraviolet light coronagraph was developed and successfully flown on three rocket flights on 13 April 1979, 16 February 1980 and 20 July 1982. During each of these flights, the Ultraviolet Light Coronagraph was flown jointly with the White Light Coronagraph provided by the High Altitude Observatory. Ultraviolet diagnostic techniques and instrumentation for determining the basic plasma parameters of solar wind acceleration regions in the extended corona were developed and verified and the understanding of the physics of the corona through the performance, analysis and interpretation of solar observations advanced. Valuable UV diagnostics can be performed in the absence of a natural solar eclipse

Investigation of a geodesy coexperiment to the Gravity Probe B relativity gyroscope program

Geodesy is the science of measuring the gravitational field of and positions on the Earth. Estimation of the gravitational field via gravitation gradiometry, the measurement of variations in the direction and magnitude of gravitation with respect to position, is this dissertation's focus. Gravity Probe B (GP-B) is a Stanford satellite experiment in gravitational physics. GP-B will measure the precession the rotating Earth causes on the space time around it by observing the precessions of four gyroscopes in a circular, polar, drag-free orbit at 650 km altitude. The gyroscopes are nearly perfect niobium-coated spheres of quartz, operating at 1.8 K to permit observations with extremely low thermal noise. The permissible gyroscope drift rate is miniscule, so the torques on the gyros must be tiny. A drag-free control system, by canceling accelerations caused by nongravitational forces, minimizes the support forces and hence torques. The GP-B system offers two main possibilities for geodesy. One is as a drag-free satellite to be used in trajectory-based estimates of the Earth's gravity field. We described calculations involving that approach in our previous reports, including comparison of laser only, GPS only, and combined tracking and a preliminary estimate of the possibility of estimating relativistic effects on the orbit. The second possibility is gradiometry. This technique has received a more cursory examination in previous reports, so we concentrate on it here. We explore the feasibility of using the residual suspension forces centering the GP-B gyros as gradiometer signals for geodesy. The objective of this work is a statistical prediction of the formal uncertainty in an estimate of the Earth's gravitation field using data from GP-B. We perform an instrument analysis and apply two mathematical techniques to predict uncertainty. One is an analytical approach using a flat-Earth approximation to predict geopotential information quality as a function of spatial wavelength. The second estimates the covariance matrix arising in a least-squares estimate of a spherical harmonic representation of the geopotential using GP-B gradiometer data. The results show that the GP-B data set can be used to create a consistent estimate of the geopotential up to spherical harmonic degree and order 60. The formal uncertainty of all coefficients between degrees 5 and 50 is reduced by factors of up to 30 over current satellite-only estimates and up to 7 over estimates which include surface data. The primary conclusion resulting from this study is that the gravitation gradiometer geodesy coexperiment to GP-B is both feasible and attractive

Shock Tube Determination of Autoionization Lifetime and Oscillator Strengths of the 352 3P 2Po-353P2 2S1/2 Doublet of Al I Scientific Report No. 2

Shock tube measurement of autoionization lifetime and oscillator strengths of states above first ionization potential for aluminu