Engineering topics

Rosenberg, A.

Publications and source records attributed to Rosenberg, A..

8 records

NASA NTRS1989

Carbon dioxide Doppler lidar wind sensor on a Space Station polar platform

A study has been performed of the feasibility of accommodating a carbon dioxide Doppler lidar on a Space Station polar platform. Results show that such an instrument could be accommodated on a single 1.5 x 2.25-m optical bench, mounted centrally on the earth facing side of the satellite. The power, weight, and thermal issues appear resolvable. However, the question of servicing the instrument remains open, until more data are available on the lifetime of an isotopic CO2 laser.

Petheram, John C.↗

NASA NTRS1986

Nd:Glass-Raman laser for water vapor dial

A tunable solid-state Raman shifted laser which was used in a water vapor Differential Absorption Lidar (DIAL) system at 9400 A is described. The DIAL transmitter is based on a tunable glass laser operating at 1.06 microns, a hydrogen Raman cell to shift the radiation to 1.88 microns, and a frequency doubling crystal. The results of measurements which characterize the output of the laser with respect to optimization of optical configuration and of Raman parameters were reported. The DIAL system was also described and preliminary atmospheric returns shown.

Kagann, R. H.↗

NASA NTRS1986

Calibration and analysis for a 0.53 micron incoherent Doppler lidar

A ground based, prototype Doppler lidar is being developed to demonstrate the feasibility of an incoherent detection technique to remotely measure winds in the atmosphere. This prototype system consists of a narrow band, single frequency laser transmitter, a high resolution, Fabry-Perot Interferometer utilizing a multichannel image plane detector and a data acquisition system. A description of the prototype Doppler lidar hardware is given in Rosenberg and Sroga, 1985. The calibration and analysis procedures for this system is described. Preliminary results from data obtained with the system pointed vertically is presented.

Sroga, J.↗

NASA NTRS1985

Development of a 0.5 micrometer incoherent Doppler lidar for space application

This paper describes the current status of a prototype 0.53 micrometer Doppler lidar system under development at RCA. This system consists of a frequency doubled Nd:YAG laser constrained to yield a narrow bandwidth, single frequency pulse, a Fabry-Perot Inteferometer (FPI) using an Image Plane Detector (IPD) to measure the backscatter spectrum for each pulse and a Data Acquisition System (DAS) to sample, store, and analyze the backscattered signal. These individual subsystem components have been assembled and preliminary atmospheric testing has recently begun. Atmospheric backscatter spectra are presented which demonstrate the capabilities of this system to distinguish between return signals from aerosols, molecules, and clouds.

Rosenberg, A.↗

NASA NTRS1980

Temperature retrievals from TIROS-N

A nonstatistical, nonlinear iterative scheme, has been developed, based on the methods of Chahine (1970), to retrieve surface temperature, vertical temperature profile and cloud distribution from TIROS-N HIRS 2/MSU observations. Fundamental to the technique is the ability to accurately calculate clear column radiances given atmospheric and surface characteristics. The cloud filtering algorithm, making simultaneous use of IR 15 micron channels and microwave channels, allows accurate infrared retrievals in the presence of up to 80 percent cloud cover. Details for the iterative scheme are presented together with preliminary results from analysis of TIROS-N data.

Susskind, J.↗

NASA NTRS1979

On nuclear spin statistics in rotational transition intensities in tetrahedral AB4 molecules

A general expression is derived for the integrated intensity of rotational transitions in the vibronic ground state of tetrahedral molecules, taking into account the nuclear spin statistics. It is shown that the ratio of this expression to previously published spin-free integrated intensities depends only on the tensor character N of the operator driving the transition, the appropriate rotational quantum numbers J and J', and the nuclear spin of the identical nuclei. Tables are given for N = 3, 4 and J no more than 50, which enable the calculation of integrated intensities for octopole and hexadecapole collision-induced dipole-moment transitions, centrifugal-distortion-induced dipole-moment transitions, and centrifugal-distortion-induced anisotropic-polarizability-tensor Raman transitions.

Rosenberg, A.↗

NASA NTRS1979

Theory of pure rotational transitions in doubly degenerate torsional states of ethane

It is shown that pure rotational transitions in doubly degenerate torsional states of C2H6 (with selection rules Delta K = 0, plus or minus 1) are made allowed by Coriolis interaction between torsion and dipole-allowed vibrations. Expressions are presented for integrated intensities from which strengths of lines in the millimeter region can be calculated.

Rosenberg, A.↗

NASA NTRS1979

Advanced Meteorological Temperature Sounder (AMTS) simulations

Simulation studies are reported on temperature retrievals from AMTS and their effect on atmospheric analysis. Observations are simulated from radiosonde reports and observed cloud cover. Temperature retrievals are performed and RMS temperature and thickness errors are calculated relative to the radiosonde profiles and compared to similarly generated HIRS statistics. Significant improvement over HIRS is found throughout the atmosphere but especially in the stratosphere and lower troposphere.

Susskin, J.↗