Measurements of the effect of horizontal variability of atmospheric backscatter on dial measurements

The horizontal variability of atmospheric backscatter may have a substantial effect on how Differential Absorption Lidar (DIAL) data must be taken and analyzed. To minimize errors, lidar pulse pairs are taken with time separations which are short compared to the time scales associated with variations in atmospheric backscatter. To assess the atmospheric variability for time scales which are long compared to the lidar pulse repetition rate, the variance of the lidar return signal in a given channel can be computed. The variances of the on-line, off-line, and ration of the on-line to off-line signals at given altitudes obtained with the dual solid-state Alexandrite laser system were calculated. These evaluations were made for both down-looking aircraft and up-looking ground-based lidar data. Data were taken with 200 microsecond separation between on-line and off-line laser pulses, 30 m altitude resolution, 5 Hz repetition rate, and the signal were normalized for outgoing laser energy

Real-time atmospheric absorption spectra for in-flight tuning of an airborne dial system

Real-time measurements of atmospheric absorption spectra are displayed and used to precisely calibrate and fix the frequency of an Alexandrite laser to specific oxygen absorption features for airborne Differential Absorption Lidar (DIAL) measurements of atmospheric pressure and temperature. The DIAL system used contains two narrowband tunable Alexandrite lasers: one is electronically scanned to tune to oxygen absorption features for on-line signals while the second is used to obtain off-line (nonabsorbed) atmospheric return signals. The lidar operator may select the number of shots to be averaged, the altitude, and altitude interval over which the signals are averaged using single key stroke commands. The operator also determines exactly which oxygen absorption lines are scanned by comparing the line spacings and relative strengths with known line parameters, thus calibrating the laser wavelength readout. The system was used successfully to measure the atmospheric pressure profile on the first flights of this lidar, November 20, and December 9, 1985, aboard the NASA Wallops Electra aircraft

Airborne Lidar measurements of the atmospheric pressure profile with tunable Alexandrite lasers

The first remote measurements of the atmospheric pressure profile made from an airborne platform are described. The measurements utilize a differential absorption lidar and tunable solid state Alexandrite lasers. The pressure measurement technique uses a high resolution oxygen A band where the absorption is highly pressure sensitive due to collision broadening. Absorption troughs and regions of minimum absorption were used between pairs of stongly absorption lines for these measurements. The trough technique allows the measurement to be greatly desensitized to the effects of laser frequency instabilities. The lidar system was set up to measure pressure with the on-line laser tuned to the absorption trough at 13147.3/cm and with the reference laser tuned to a nonabsorbing frequency near 13170.0/cm. The lidar signal returns were sampled with a 200 range gate (30 vertical resoltion) and averaged over 100 shots

Сравнительный анализ вертикального распределения ноктуоидных чешуекрылых (Lepidoptera: Noctuoidea) центральных частей хребтов Киргизского, Джумгалтоо и Ферганского: предварительные результаты

Приводятся предварительные результаты сравнительного анализа вертикального распределения чешуекрылых ноктуоидного комплекса центральных частей хребтов Киргизского, Джумгалтоо и Ферганского. Для фауны трех хребтов отмечено 346 видов Noctuoidea, из них по хребтам: 246 видов на Киргизском хр., 210 видов на хр. Джумгалтоо и 164 вида на Ферганском хр. Распределение по вертикальным поясам: низкогорья Киргизского хр. 134 вида, хр. Джумгалтоо 85 видов, Ферганского хр. 93 вида; среднегорья Киргизского хр. 114 видов, хр. Джумгалтоо 191 вид, Ферганского хр. 125 видов; высокогорья Киргизского хр. 52 вида, хр. Джумгалтоо 96 видов, Ферганского хр. 50 видов; сверхвысокогорья Киргизского хр. 9 видов, хр. Джумгалтоо 17 видов, Ферганского хр. 12  видов. Фауны обследованных хребтов ни в целом, ни по поясам несходны, за исключением низкогорного пояса хр. Ферганский и Джумгалтоо. Ареалогическая структура фауны состоит из 8 типов ареалов, объединенных в 2 комплекса. Чем выше расположен вертикальный пояс, тем меньше в нем доля видов с обширными ареалами; то же касается и ядра фауны пояса

Анализ биотопического распределения булавоусых чешуекрылых Нижегородской области (Lepidoptera, Rhopalocera)

Рассматривается биотопическое распределение булавоусых чешуекрылых Нижегородской области и его закономерности. Выделено 7 групп биотопов, описаны их фауны. Определены стенотопные виды и виды разной степени эвритопности, определено их соотношение. Определены виды с наибольшим адаптационным потенциалом как наиболее вероятные кандидаты на заселение нетипичных биотопов на данной территории

Butterfly fauna of Dzhumagal-Too mountain ridge in Kyrgyzstan (Lepidoptera: Papilionoidea and Hesperioidea)

A list of butterflies from Dzhumgal-Too mountain ridge in Kirghizia (Inner Tian-Shan) is presented. It contains 115 species

Bayesian Network Structure Learning with Permutation Tests

In literature there are several studies on the performance of Bayesian network structure learning algorithms. The focus of these studies is almost always the heuristics the learning algorithms are based on, i.e. the maximisation algorithms (in score-based algorithms) or the techniques for learning the dependencies of each variable (in constraint-based algorithms). In this paper we investigate how the use of permutation tests instead of parametric ones affects the performance of Bayesian network structure learning from discrete data. Shrinkage tests are also covered to provide a broad overview of the techniques developed in current literature.Comment: 13 pages, 4 figures. Presented at the Conference 'Statistics for Complex Problems', Padova, June 15, 201

Differential absorption lidars for remote sensing of atmospheric pressure and temperature profiles

A near infrared differential absorption lidar technique is developed using atmospheric oxygen as a tracer for high resolution vertical profiles of pressure and temperature with high accuracy. Solid-state tunable lasers and high-resolution spectrum analyzers are developed to carry out ground-based and airborne measurement demonstrations and results of the measurements presented. Numerical error analysis of high-altitude airborne and spaceborne experiments is carried out, and system concepts developed for their implementation