Maxometers (peak wind speed anemometers)

An instrument for measuring peak wind speeds under severe environmental conditions is described, comprising an elongated cylinder housed in an outer casing. The cylinder contains a piston attached to a longitudinally movable guided rod having a pressure disk mounted on one projecting end. Wind pressure against the pressure disk depresses the movable rod. When the wind reaches its maximum speed, the rod is locked by a ball clutch mechanism in the position of maximum inward movement. Thereafter maximum wind speed or pressure readings may be taken from calibrated indexing means

Industry views on water resources planning methods – prospects for change in England and Wales

This paper describes a qualitative study of practitioner perspectives on regulated water resources planning practice in England and Wales. The study focuses on strengths and weaknesses of existing practice and the case for change towards a risk-based approach informed by stochastic modelling assessments. In-depth, structured interviews were conducted to capture the views of planners, regulators and consultants closely involved in the planning process. We found broad agreement that the existing water availability assessment methods are fallible; they lack transparency, are often highly subjective and may fail to adequately expose problems of resilience. While most practitioners believe these issues warrant a more detailed examination of risk in the planning process, few believe there is a strong case for a fundamental shift towards risk-based planning informed by stochastic modelling assessments. The study identifies perceived business risks associated with change and exposes widespread scepticism of stochastic methods

NASA/MSFC FY-83 Atmospheric Research Review

Atmospheric research conducted at the Marshall Space Flight Center in FY 1983 is discussed. Clear air turbulence, gusts, and fog dispersal near airports is discussed. The use of Doppler Lidar signals in discussed, as are low level flow conditions that are hazardous to aircraft

On the Form of the Spitzer Leavitt Law and its Dependence on Metallicity

The form and metallicity-dependence of Spitzer mid-infrared Cepheid relations are a source of debate. Consequently, Spitzer 3.6 and 4.5 um period-magnitude and period-color diagrams were re-examined via robust routines, thus providing the reader an alternative interpretation to consider. The relations (nearly mean-magnitude) appear non-linear over an extensive baseline (0.45< logPo <2.0), particularly the period-color trend, which to first-order follows constant (3.6-4.5) color for shorter-period Cepheids and may transition into a bluer convex trough at longer-periods. The period-magnitude functions can be described by polynomials (e.g., [3.6 um]=Ko-(3.071+-0.059) logPo-(0.120+-0.032)logPo^2), and Cepheid distances computed using 3.6 and 4.5 um relations agree and the latter provides a first-order consistency check (CO sampled at 4.5 um does not seriously compromise those distances). The period-magnitude relations appear relatively insensitive to metallicity variations ([Fe/H]~0 to -0.75), a conclusion inferred partly from comparing galaxy distances established from those relations and NED-D (n>700), yet a solid conclusion awaits comprehensive mid-infrared observations for metal-poor Cepheids in IC 1613 ([Fe/H] -1). The Cepheid-based distances were corrected for dust obscuration using a new ratio (i.e., A(3.6)/E(B-V)=0.18+-0.06) deduced from GLIMPSE (Spitzer) data.Comment: To appear in Ap

Documenting Antarctic Alteration of Eucrites

When meteorites were discovered in Antarctica, it was anticipated that terrestrial alteration would be at a minimum because of their deepfreeze storage where chemical reaction rates would be low. However, early compositional and petrologic studies established the presence of terrestrial alteration phases (e.g., [1, 2]). These were especially prevalent in chondrites because metal and troilite are most susceptible to terrestrial alteration [3]. Howardites, eucrites and diogenites (HEDs) are less prone to alteration because they have low abundances of metal and troilite. Nevertheless, investigations of HED meteorites document a wide array of mineralogical, compositional and isotopic effects of terrestrial alteration (e.g., [4-8]). Studies of the mineralogical effects of alteration [4] were done with old scanning electron microscope (SEM) technology which could only image small regions at a time. The micro-context of alteration phases was revealed, but larger-scale context was difficult to establish. Here we demonstrate the utility of wholethin-section X-ray mapping of eucrites by modern SEMs to document large-scale distributions of alteration materials which serve to evaluate sample freshness, highlight regions for detail study, and facilitate testing a hypothesis for alteration of eucrites [8

Atmospheric radiation model for water surfaces

An atmospheric correction model was extended to account for various atmospheric radiation components in remotely sensed data. Components such as the atmospheric path radiance which results from singly scattered sky radiation specularly reflected by the water surface are considered. A component which is referred to as the virtual Sun path radiance, i.e. the singly scattered path radiance which results from the solar radiation which is specularly reflected by the water surface is also considered. These atmospheric radiation components are coded into a computer program for the analysis of multispectral remote sensor data over the Great Lakes of the United States. The user must know certain parameters, such as the visibility or spectral optical thickness of the atmosphere and the geometry of the sensor with respect to the Sun and the target elements under investigation

The maxometer-dynamic and static tests

The ability to withstand extreme environmental conditions, such as the high flow velocities and extreme temperatures associated with the launch of aerospace vehicles, was considered in the developement of two maxometer models which are capable of measuring extremely high wind speeds (130 m/sec) and retaining a record of the peak speed over any given time period. The dynamic and static tests of these models are reported, along with pertinent results

Analog tree-organized multiplexer

An analog tree-organized multiplexer (ATOM) which is intended for use in the telemetry system of an interplanetary spacecraft is designed. The ATOM will be fabricated by a monolithic, dielectric isolation process, and will contain silicon junction field effect transistors (JFET) as the active elements. The effect of the radiation environment on the performance of the ATOM is analyzed. The result indicates that the expected radiation environment will cause only minor changes in the preradiation characteristics of ATOM. The JFET in the ATOM is designed to meet the electrical requirements when fabricated by either the double poly-dielectric isolation process or the raised dielectric isolation process. The effect of the heat treatment required for the dielectric isolation process on the diffusion profile of the JFET is described. The layout of the ATOM circuit for fabrication by either the double poly or raised dielectric isolation process is also given

Signal-to-noise ratio estimation in digital computer simulation of lowpass and bandpass systems with applications to analog and digital communications, volume 3

Techniques are developed to estimate power gain, delay, signal-to-noise ratio, and mean square error in digital computer simulations of lowpass and bandpass systems. The techniques are applied to analog and digital communications. The signal-to-noise ratio estimates are shown to be maximum likelihood estimates in additive white Gaussian noise. The methods are seen to be especially useful for digital communication systems where the mapping from the signal-to-noise ratio to the error probability can be obtained. Simulation results show the techniques developed to be accurate and quite versatile in evaluating the performance of many systems through digital computer simulation