Microcomputer based data acquisition for audio signals

The problem of interfacing a low cost microcomputer—the Commodore 3032—to external devices is reviewed. The essential features of a general purpose interface unit are described and an explanation is given, in general terms, of how this unit can be used to transfer digitised samples of audio signals to 3032 user memory for software processing. A specific system is described which allows sampling and storage at rates of up to 71 kbytes per second for a single channel and up to $\text{43 kbytes × 2}$ per second for two channels. More than two channels can be sampled at correspondingly lower rates. Some possible applications are indicated.     

Characteristics of the wind field in clouds based on incoherent radar data

Main Geophysical Observatory. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 33, No. 2, pp. 164–169, February, 1990.     

Librations of mercury in longitude based on the data of ground-based radar observations

The amplitude, phase, and period of free liberation and the amplitudes of five fundamental harmonics of forced (annual, semi-annual, …) librations of Mercury in longitude are determined based on the analytical theory of Mercury’s liberation (on an elliptical orbit) in longitude using a high-accuracy complex method for ground-based radar tracking.     

Coal exploration technology based on visible-infrared spectra and remote sensing data

In the modern society, coal is used as the main source of energy. In this paper, based on the theory of the remote sensing, the distributions of the coal mine area through the satellite imagery are measured. First, the satellite pictures of coal mining regions in Quangninh of Vietnam and Huolinhe of China were gathered as the experimental data. Second, spectrometer was used to measure the spectral data of the coal samples of these two regions. The measured data provide comprehensive and accurate spectral characteristics of the coal. Then the classification model can be built by the improved extreme learning machines algorithm based on the measured data and the remote sensing data. Finally, the distribution image of the coal mine area is obtained accurately based on the classification model.     

Assessment and robust reconstruction of laser radar signals

In direct-detection imaging, laser radar speckle noise, drop-outs, and outliers have to be considered in order to ensure high accuracy and reliability of measurement data. The most common approach for the stabilization of laser radar data is temporal averaging over several shots. This, however, is not in all cases the best method for the reconstruction of noisy image data. It is shown that principal component reconstruction can yield a remarkable improvement of accuracy and robustness of range data.     

The application of lightning forecasting based on surface electrostatic field observations and radar data

This paper presents an analysis of lightning forecasting based on atmospheric electrostatic field (EF), radar and lightning location data in Nanjing of China. The warning behavior with EF data in summer of 2009 was analyzed and the suitable EF warning indexes were determined. To improve EF warnings effect, a method of cloud-ground (CG) lightning nowcasting based on EF observations, radar data, etc. was proposed and the best radar forecasting index was selected in the paper. The experimental (2009) and independent test (2010) results show that POD is 82.7%, FAR is 14.6%, CSI is 72.4% and average lead time is 20.8 min.     

Method for estimating coherent properties of radar signals

We propose a method for estimating coherent properties of signals within the framework of the correlation theory. A quantitative measure of coherence is obtained in the form of entropy of the signal energy distribution over the eigensubspaces of the correlation matrix of the signal. Examples are given to illustrate the effectiveness of the obtained measure. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 49, No. 1, pp. 82–87, January 2006.     

Detection of small signals in mass spectra

The results of the chromatographic–mass spectrometric analysis of a mixture containing a compound with low protonation efficiency have been given. A software package for preliminary processing of mass spectra is used for determining the peak parameters of the compound ions. The reliability of the processing results has been confirmed by comparison with the tabular data for the isotope masses and the isotopic composition of the component. The mass spectrum has been interpreted by calculating the peak areas and centroids together by evaluating the standard deviation of the center of the peak. The results of processing the mass spectrum using the mMass program have been given.

     

On the measurement of polarization parameters of optical radar signals

The polarization parameters of optical radar signals, which are characterized by parameters resulting from entropy of partially polarized light waves, are discussed. It is shown that the properties of the signal can be represented by a factor which is a ratio of entropies, and by two parameters of the polarization ellipse. The proposed method using quasilinearly polarized signals of He-Ne laser at 632.8 nm was applied to the investigations of a number of typical materials.On leave from the Technical University of Warsaw, Warsaw Poland under Exchange Agreement between Poland and Austria. The address of the author: ul. Wieluska, 18 m.24 01 240, Warszawa. Poland.     

A MAP estimator based on geometric Brownian motion for sample distances of laser triangulation data

The proposed algorithm is designed to enhance the line-detection stability in laser-stripe sensors. Despite their many features and capabilities, these sensors become unstable when measuring in dark or strongly-reflective environments. Ambiguous points within a camera image can appear on dark surfaces and be confused with noise when the laser-reflection intensity approaches noise level. Similar problems arise when strong reflections within the sensor image have intensities comparable to that of the laser. In these circumstances, it is difficult to determine the most probable point for the laser line. Hence, the proposed algorithm introduces a maximum a posteriori estimator, based on geometric Brownian motion, to provide a range estimate for the expected location of the reflected laser line.     

样本空间排序法评价瞬时辐照无失效数据研究

为降低瞬时辐照抽样检验中现行经典非参数法的评价结果的保守性,引入样本空间排序法,从理论和实例两方面计算无失效数据的生存概率置信下限,并与经典非参数法进行对比。结果是,样本空间排序法不仅提高生存概率的置信下限,还增大这些置信限所对应的剂量率范围。该研究结果表明样本空间排序法提高了数据利用率,降低了保守性,可减少试验成本。     

Model calculations of the radiation dose and LET spectra on LDEF and comparisons with flight data

Ionizing radiation environment models, a 3-D spacecraft mass model, and radiation transport codes have been used to predict the radiation dose and linear energy transfer (LET) spectra measured at various locations on the LDEF satellite. The predictions are compared with thermoluminescent dosimeter measurements of the trapped proton and electron doses and with LET spectra measured by plastic nuclear track detectors. The predicted vs observed comparisons indicate some of the uncertainties of present ionizing radiation environment models for low Earth-orbit missions.     

The vibrational spectrum of the OCS molecule based on the data on spectra of liquid and cryosolutions

The IR absorption spectra of liquid OCS (T = 135(1) K) and of the following solutions—OCS + Ar (T = 90 K), OCS + N₂ (T = 90 K), OCS + Kr (T = 130 K), and OCS + Xe (T = 163 K)—are measured in the range 800–7000 cm^?1. From 16 to 40 bands corresponding to transitions to vibrational states up to the third order inclusive are interpreted for basic isotope modification and for the isotopically substituted molecules ¹⁸O¹²C³²S, ¹⁶O¹³C³²S, and ¹⁶O¹²C³⁴S. In the spectra of the liquids, the spectral moments M(1) and M(2) of all the observed bands are determined. The harmonic frequencies ω _i and the anharmonicity constants x _ik are calculated for all the systems, including the liquid. The anharmonicity is found to be constant within the experimental error. A large shift Δω₃ is primarily determined by the dipole-induced dipole interaction.     

Sensory coding and the second spectra of natural signals

Natural auditory and visual stimuli are shown to demonstrate consistent non-Gaussian signatures: their phase-only second spectra behave approximately as the inverse square root of frequency, a property which is due to a predominance of difference beats between Fourier components at slightly offset frequencies. These second spectra also demonstrate statistical scale invariance, a hypothesis which is tested explicitly by computing phase-only second spectra from bandpass-filtered data. The bandpass frequency selectivity observed experimentally in sensory cells is shown to be qualitatively consistent with a strategy of exploiting the non-Gaussian structure of natural signals.     

Acceleration target detection based on LFM radar

In radar systems, the echo signal caused by an accelerated target can be similarly considered as linear frequency modulation (LFM) signal. In high signal-to-noise ratio (SNR), discrete polynomial-phase transform (DPT) algorithm can be used to detect the echo signal, as it has low computation complexity and high real-time performance. However, in low SNR, the DPT algorithm has a large mean square error of the rate of frequency modulation and a low detection probability. In order to detect LFM signal in low SNR, this paper proposes a detection method, segment discrete polynomial-phase transform (SDPT), which means, at first, dividing the whole echo pulses into several segments with same duration in time domain, and then, using coherent accumulation method of DFT to segments, at last, processing this signal with DPT in intra-segment. In the case of a large number of segments, the SDPT can improve the output SNR. In addition, in a certain SNR, to the target signal with big sampling interval, large acceleration and less segments, this paper proposes an algorithm to detect the LFM signal generated from the combination of an improved DPT (IDPT) and fractional Fourier transform (FRFT). The output SNR of this algorithm is connected with the length of time delay. In the simulation, when the length of the time delay is 0.2 N, the output SNR is 2.5 dB more than that which results from directly using DPT. Finally, the detection performance and algorithm complexity of the proposed algorithm were analyzed, and the simulated and measured data verify the effectiveness of the algorithm.