Data analysis techniques: Spectral processing

The individual steps in the data processing scheme applied to most radars used for wind sounding are analyzed. This processing method uses spectral analysis and assumes a pulse Doppler radar. Improvement in the signal to noise ratio of some radars is discussed

Capabilities and limitations of existing MST radars: Colorado wind profilers

The Wave Propagation Laboratory is developing a ground-based remote sensing system called PROFILER to measure troposphere parameters currently measured in operational meteorology by radiosondes. The prototype PROFILER uses two radars for wind sounding: a 6-m radar located at Platteville, Colorado, and a 33-cm radar located at Denver's Stapleton International Airport. In addition, a network of three 6-m wind-profiling radars is being installed in Colorado, and a fourth site is planned. The location of the five radars, their characteristics, and their limitations are described

Elimination of range-aliased echoes in the VHF radars

Very high frequency radars designed to measure tropospheric wind profiles usually detect scattering to a maximum height of about 20 km. If the antenna elevation angle is 45 degrees or more above the horizon, the maximum range of interest is less than 30 km. A VHF pulsed Doppler radar wind Profiler can, therefore, be operated at high pulse repetition rates. The maximum bandwidth allowed is about 0.5 MHz so a radar with uncoded pulses can operate with a duty cycle of 1 to 10%, depending on the desired height resolution. It is possible to operate a tropospheric wind profiler that utilizes all the average power available from the transmitter without the complexity of coded pulses. However, the VHF radar can detect echoes from the mesosphere on occasion and, with high pulse repetition rates, these echoes occur at the same apparent range as the tropospheric echoes. These mesospheric echoes may be stronger than the tropospheric signals. The range-aliased mesospheric echoes can be greatly attenuated or effectively eliminated

Progress and plans for the Colorado Wind Profiler Network

Since January 1983, the Wave Propagation Laboratory (WPL) has placed four wind profiling radars in operation. These radars and the Platteville radar (originally developed by the Aeronomy Laboratory (AL0 and jointly operated by AL and WPL for several years) form the Colorado Wind Profiler Network. Plans and improvements for the Colorado Wind Profilers are summarized

Performance characteristics of wind profiling radars

Doppler radars used to measure winds in the troposphere and lower stratosphere for weather analysis and forecasting are lower-sensitivity versions of mesosphere-stratosphere-troposphere radars widely used for research. The term wind profiler is used to denote these radars because measurements of vertical profiles of horizontal and vertical wind are their primary function. It is clear that wind profilers will be in widespread use within five years: procurement of a network of 30 wind profilers is underway. The Wave Propagation Laboratory (WPL) has operated a small research network of radar wind profilers in Colorado for about two and one-half years. The transmitted power and antenna aperture for these radars is given. Data archiving procedures have been in place for about one year, and this data base is used to evaluate the performance of the radars. One of the prime concerns of potential wind profilers users is how often and how long wind measurements are lacking at a given height. Since these outages constitute an important part of the performance of the wind profilers, they are calculated at three radar frequencies, 50-, 405-, and 915-MHz, (wavelengths of 6-, 0.74-, and 0.33-m) at monthly intervals to determine both the number of outages at each frequency and annual variations in outages

Thermally-activated charge reversibility of gallium vacancies in GaAs

The dominant charge state for the Ga vacancy in GaAs has been the subject of a long debate, with experiments proposing $-$1, $-$2 or $-$3 as the best answer. We revisit this problem using {\it ab initio} calculations to compute the effects of temperature on the Gibbs free energy of formation, and we find that the thermal dependence of the Fermi level and of the ionization levels lead to a reversal of the preferred charge state as the temperature increases. Calculating the concentrations of gallium vacancies based on these results, we reproduce two conflicting experimental measurements, showing that these can be understood from a single set of coherent LDA results when thermal effects are included.Comment: 4 pages, 4 figure

The phylogeny of the Charadriiformes (Aves): a new estimate using the method of character compatibility analysis

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72525/1/j.1096-3642.1978.tb00375.x.pd

Rule 10b-5-Application of the In Pari Delicto Defense in Suits Brought Against Securities Brokers by Customers Who Have Traded on Inside Information

This Note advocates that courts should permit tipper defendants to assert the in pari delicto defense in private 10b-5 cases against tippee plaintiffs unless one of the first three exceptions to the analytical framework applies. Part II of this Note discusses the purpose and application of the in pari delicto defense and the four situations in which courts have rejected it. Part II also illustrate show courts analyze the in pari delicto defense in contract, anti-trust, and non-10b-5 securities cases. Part III provides a general background on the purpose of the Securities and Exchange Act of 1934 and rule 10b-5, and analyzes the current split among federal circuit courts on the application of the in pari delicto defense in rule 10b-5 actions. Part IV concludes that courts should leave the parties to the illegal agreements undisturbed and should not apply the residual exception to disallow the defense in 10b-5 actions.When one of the first three exceptions to the defense does apply, however, courts should continue to allow plaintiff tippees to recover against tipper defendants who have given the tippees false inside information

A procedure model for evaluating IT-security investments

The security of information systems is a vital factor for companies nowadays. In order to achieve an adequate level of security, a variety of distinct measures is available, ranging from technical meas-ures to organizational measures. In near past suitable methods for decision support especially for the assessment of the profitability of IT-security investments have been developed. But integrated procedure models for a complete it-security controlling can neither be found in literature nor in practice. With this article, we propose a method framework that enables the analysis of the results of alternative security investments from a process-oriented perspective. As a basis, we have conducted an in-deep analysis of the state-of-the-art in the fields of IT-Business-Alignment and IT-security management in order to identify suitable concepts for the framework. A special focus lies on the requirements of IT-security controlling of critical business processes.Безпека інформаційних систем у теперішній час є життєво важливим фактором для компаній. Багато різних вимірів, від технічних до організаційних, є доступними для досягнення прийнятного рівня безпеки. У недалекому минулому було розроблено методи підтримки прийняття рішень при оцінюванні прибутковості інвестицій у IT-безпеку. Проте інтегральні процедурні моделі для повного управління IT-безпекою до цього часу не знайдені – ані у літературі, ані на практиці. У цієї статті ми пропонуємо середовище, яке дає можливість аналізувати результати альтернативних інвестицій у безпеку з точки зору, орієнтованої на процеси. Ми здійснили поглиблений аналіз сучасного стану справ у галузях синхронізації IT та бізнесу та управління IT-безпекою з метою ідентифікувати прийнятні концепції для цього середовища. Спеціальну увагу приділено вимогам до IT-безпеки критичних бізнес-процесів

Performance of the Colorado wind-profiling network, part 1.5A

The Wave Propagation Laboratory (WPL) has operated a network of radar wind Profilers in Colorado for about 1 year. The network consists of four VHF (50-MHz) radars and a UHF (915-MHz) radar. The Platteville VHF radar was developed by the Aeronomy Laboratory (AL) and has been operated jointly by WPL and AL for several years. The other radars were installed between February and May 1983. Experiences with these radars and some general aspects of tropospheric wind measurements with Doppler radar are discussed