The measurement of ionospheric absorption using extraterrestrial radio waves

Introduction: The discovery by Jansky in 1932 of the presence of radio waves incident upon the earth from outer space has led to several new methods of studying the earth's upper atmosphere. This report describes the manner in which these extraterrestrial radio waves may be used to measure the radio absorption characteristics of the ionosphere. It opens with a brief discussion of the theory of ionospheric absorption; this is followed by a description of the basic principles involved in this new technique. Two different types of equipment which may be used for this type of absorption measurement are then discussed. The report concludes with a brief summary of three types of ionospheric absorption phenomena which have been studied at various latitudes with such equipments.Introduction – Section I Summary of Theory of Ionospheric Absorption – Section II Extraterrestrial Radio Waves and Ionospheric Absorption – Section III The Measurement of Ionospheric Absorption Using Extraterrestrial Radio Waves : With a simple receiver ; The continually self-calibrating system ; Some additional points – Section IV Some Experimental Observations of Ionospheric Absorption Using Extraterrestrial Radio Waves – BibliographyYe

Experiment Luxembourg

The earlier orbits and ephemerides for the Soviet satellites were not sufficiently accurate to be very useful in making observations in Alaska. Extrapolations from our own observations gave better predictions. This merely pointed out the fact that rough observations of meridian transits at high latitudes will give better values of the inclination of the orbit than precision observations at low latitudes. Hence, it was decided to observe visually the meridian transits estimating the altitude by noting the position with respect to the stars or using crude alidade measurements. The times of the earlier observations were observed on a watch or clock and the clock correction obtained from WWV. Later the times were determined with the aid of stop watches, taking time intervals from WWV signals. This rather meager program of optical observations of the Soviet satellites was undertaken to give supplementary data for use of the radio observations, and particularly to assist in the prediction of position of the satellite so that the 61-foot radar of Stanford Research Institute could be set accurately enough to observe it (the beam width at the half-power points is about 3°). This report contains primarily the visual observations made at the Geophysical Institute by various members of the staff, and a series of observations by Olaf Halverson at Nome, Alaska. In addition there is a short discussion of the geometry of the trajectory, the illumination of a circumpolar satellite, and a note on the evaluation of Brouwer's moment factors.The research reported In this document has been sponsored by the Geophysics Research Directorate of the Air Force Cambridge Research Center* Air Research and Development Command, under Contract AF 19(604)-3880.List of Figures -- Introduction -- Present knowledge of the electron densities and collision frequencies in the D region of the ionosphere. -- The theory of radio wave interaction. -- The outline of the planned experiment. -- Some comments about the planned experiment. Some comments about gyrointeraction. -- Conclusion -- Acknowledgements -- ReferencesYe

Bayesian Inference under Cluster Sampling with Probability Proportional to Size

Cluster sampling is common in survey practice, and the corresponding inference has been predominantly design-based. We develop a Bayesian framework for cluster sampling and account for the design effect in the outcome modeling. We consider a two-stage cluster sampling design where the clusters are first selected with probability proportional to cluster size, and then units are randomly sampled inside selected clusters. Challenges arise when the sizes of nonsampled cluster are unknown. We propose nonparametric and parametric Bayesian approaches for predicting the unknown cluster sizes, with this inference performed simultaneously with the model for survey outcome. Simulation studies show that the integrated Bayesian approach outperforms classical methods with efficiency gains. We use Stan for computing and apply the proposal to the Fragile Families and Child Wellbeing study as an illustration of complex survey inference in health surveys

A map on the space of rational functions

We describe dynamical properties of a map $\mathfrak{F}$ defined on the space of rational functions. The fixed points of $\mathfrak{F}$ are classified and the long time behavior of a subclass is described in terms of Eulerian polynomials

Preliminary design-lift/cruise fan research and technology airplane flight control system

This report presents the preliminary design of a stability augmentation system for a NASA V/STOL research and technology airplane. This stability augmentation system is postulated as the simplest system that meets handling qualities levels for research and technology missions flown by NASA test pilots. The airplane studied in this report is a T-39 fitted with tilting lift/cruise fan nacelles and a nose fan. The propulsion system features a shaft interconnecting the three variable pitch fans and three power plants. The mathematical modeling is based on pre-wind tunnel test estimated data. The selected stability augmentation system uses variable gains scheduled with airspeed. Failure analysis of the system illustrates the benign effect of engine failure. Airplane rate sensor failure must be solved with redundancy

Technical management techniques for identification and control of industrial safety and pollution hazards

Constructive recommendations are suggested for pollution problems from offshore energy resources industries on outer continental shelf. Technical management techniques for pollution identification and control offer possible applications to space engineering and management

Heart failure is common in diabetic cats : findings from a retrospective case-controlled study in first-opinionpractice

Diabetes mellitus is common in the cat and the prevalence of this condition appears to be increasing (Peterson 1998,Rand and Marshall 2004, Rand and others 2004). The prognosis for cats with diabetes mellitus in first opinion practice has received little attention in the literature; few data indicate why diabetic cats die. Death in people with diabetes is overwhelmingly because of cardiovascular disease (Grundy and others 1999, Almdal and others 2004, Bell 2004, Bertoni and others 2004, Nichols and others 2004). Experimental induction of diabetes mellitus in various laboratory mammals also causes cardiovascular disease and heart failure so that the prevalence of cardiac disease and failure in diabetic cats seemed worthy of examination. The purpose of this study was to examine the prognosis and cause of death for a cohort of consecutive cases of feline diabetes mellitus diagnosed in a first opinion veterinary practice, and to compare these with control cats matched for age, breed and sex

Response of a small-turboshaft-engine compression system to inlet temperature distortion

An experimental investigation was conducted into the response of a small-turboshaft-engine compression system to steady-state and transient inlet temperature distortions. Transient temperature ramps range from less than 100 K/sec to above 610 K/sec and generated instantaneous temperatures to 420 K above ambient. Steady-state temperature distortion levels were limited by the engine hardware temperature list. Simple analysis of the steady-state distortion data indicated that a particle separator at the engine inlet permitted higher levels of temperature distortion before onset of compressor surge than would be expected without the separator

Lattice-dynamical calculation of phonon scattering at a disordered interface

For an fcc crystal with central force interactions and separately for a scalar model on a square lattice, we compute exactly the phonon transmission coefficient $T(\omega)$ through a disordered planar interface between two identical semi - infinite leads. At high frequencies $T(\omega)$ exhibits a strong frequency dependence which is determined by the correlation length of the disorder.Comment: to appear in Physica B, proceedings of the 9th international conference on phonon scatterin