Aerosol speckle effects on atmospheric pulsed lidar backscattered signals

Lidar systems using atmospheric aerosols as targets exhibit return signal amplitude and power fluctuations which indicate speckle effects. The effects of refractive turbulence along the path on the aerosol speckle field propagation and on the decorrelation time are studied for coherent pulsed lidar systems

Concave grating spectrometer Patent

Concave grating spectrometer for use in near and vacuum ultraviolet region

Atmospheric effects on coherent laser systems

Effects of the truncation of the gaussian beam by the telescope on the signal to noise ratio were studied. Finite and infinite beams were also considered, along with the refractive index structure constant

On modeling pollution-generating technologies

We distinguish between intended production and residual generation and introduce the concept of by-production. We show that by-production provides the fundamental explanation for the positive correlation that is observed between intended production and residual generation. Most of the existing literature attributes the observed positive correlation to abatement options available to firms. We show that abatement options of firms add to the phenomenon of by-production in strengthening the observed positive correlation. The existing literature usually does not explicitly model abatement options of firms, but considers a reduced form of he technology, which satisfies standard disposability assumptions with respect to all inputs and intended outputs. We show that more than one implicit production relation is needed to capture all the technological trade-offs that are implied by by-production. From our model, we are able to derive a reduced form of the technology that is in the spirit of the one that is usually studied in the literature. However, we nd that our reduced form technology violates standard disposability with respect to inputs and intended outputs that cause pollution. We derive implications from the phenomenon of by-production for the econometric and Data Envelopment Analysis (DEA) speci cations of pollution-generating technologies. We derive a DEA specification of technologies that satisfy by-production. Such a specification can be used to study issues relating to measurement of efficiency, marginal abatement costs, productivity, etc., of firms with technologies that generate pollution. JEL Codes: D20 ; D24 ; D62 ; Q50pollution-generating technologies ; free disposability ; weak disposability ; data envelope analysis ; technical efficiency measurement

Atmospheric effects on CO2 laser propagation

An investigation was made of the losses encountered in the propagation of CO2 laser radiation through the atmosphere, particularly as it applies to the NASA/Marshall Space Flight Center Pulsed Laser Doppler System. As such it addresses three major areas associated with signal loss: molecular absorption, refractive index changes in a turbulent environment, and aerosol absorption and scattering. In particular, the molecular absorption coefficients of carbon dioxide, water vapor, and nitrous oxide are calculated for various laser lines in the region of 10.6 mu m as a function of various pressures and temperatures. The current status in the physics of low-energy laser propagation through a turbulent atmosphere is presented together with the analysis and evaluation of the associated heterodyne signal power loss. Finally, aerosol backscatter and extinction coefficients are calculated for various aerosol distributions and the results incorporated into the signal-to-noise ratio equation for the Marshall Space Flight Center system

On modeling pollution-generating technologies

Distinguishing between intended ("good") production and unintended or residual ("bad") generation, we introduce the concept of by-production. In by-production technologies, pollution is an output that satises a "costly disposability" assumption and violates standard free disposability with respect to pollution-causing inputs. Our approach therefore differs substantially from standard approaches to modeling pollution-generating technologies. We show how by-production can be modeled using data envelopment analysis (DEA) methods. With an electric power plant database, we illustrate shortcomings under by-production of two popular eciency indexes: the hyperbolic index and the directional distance function. We propose and implement an alternative eciency index with superior properties.pollution-generating technologies, free disposability, weak disposability, data envelopment analysis, environmental and technical eciency measurement

Dipole Moments of Some Substituted Benzenes and Pyridines. Part III. Chloro-and Bromo Ethyl Benzenes

The dipole moments of six ethyl substituted benzenes were determined in dilute solution in benzene. The effects of methyl and ethyl groups on other substituent in the benzene ring have been discussed in the light of the observed moments