Дослідження якісних показників поляризаційної селекції об’єктів на фоні пасивних завад в поляризаційно-доплерівській радіолокаційній системі

The optimal algorithm of polarization-Doppler selection of targets against the background of passive interference is considered. The polarimetric properties of scattered electromagnetic radiation of objects. The functionally-determined mathematical model of the useful signal, structure and correlation characteristics of the internal radiation of the receiver is determined. The algorithm of optimal processing, synthesized within the method of maximum likelihood, is considered for two limit cases. Algorithmic actions in the processing of passive interference and methods of their compensation are considered and investigated. Based on the obtained results, the expression for the algorithm of compensation of interferences reflected from the earth's surface is written. The obtained algorithm equalizes the variance of the input signals and compensates the residual variance with the help of weight coefficients. On the basis of the developed algorithm the scheme of the structurally simplified optimum compensator of passive disturbances is formed. Feature processing of useful signals in the compensation scheme is investigated. To ensure the adaptability of the generated algorithm, the coefficient of the variance ratio is based on the results coming from the variance meter. It is proposed to introduce quality indicators of polarization object selection on the background of the underlying surface, which combines indicators of efficiency of passive interference compensation and indicators of efficiency of useful signal-processing against the background of internal noise of receivers. The corresponding dependence of the indicators on the correlation coefficients of passive interference of different polarizations, as well as on the coefficients that separately characterize the level of difference in signal intensities and interference in the reception channels. The information value of each indicator of the efficiency of polarization signal selection from the ratio of the input variances, the correlation coefficient of passive interference and the ratio of the input signals is investigated.The obtained results are proposed to be used to improve the quality of polarization selection of objects in ground-based and aerospace-based radar systems.

Оптимізація поляризаційно-доплерівської селекції малорозмірних об’єктів на тлі підстильної поверхні

Using the method of maximum likelihood, the optimal algorithm of polarization-Doppler selection of objects on the background of the underlying surface, hydrometeors, urban buildings from aerospace carriers of radio electronic equipment has been synthesized. To solve the problem polarimetric properties of the scattered electromagnetic radiation of natural environments and anthropogenic objects were analyzed.The functional-deterministic mathematical model of the useful signalis determined. When solving the optimization problem, the method of maximum likelihood functionality and likelihood functionality for correlated processes were used, which contains the inverse matrix of inverse correlation functions of the observation equation. The obtained signal processing algorithm includes operations of spectral resection of passive interference. Polarization compensation of passive interference is performed by a combination of interchannel subtraction of the reflected signals of different polarizations. The quasi-optimal features of the synthesized algorithm, which has an obvious physical value and is optimal in the absence of internal noise, are considered. Based on the obtained results, a block diagram of the polarization-Doppler noise compensator and selection of useful signals against the background of noise reflections from the earth's surface has been developed. The study of the physical characteristics of the elements of the polarization covariance matrix of interferences at a high level of correlation of reflections of passive interferences of different polarizations is conducted.Based on the obtained results, it is proposed to introduce indicators of efficiency of passive interference compensation and selection of useful signals. The results of the analysis of the obtained indicators depending on the coefficient of the ratio of variances of passive interference indicate the need to use the polarization differences between signals and interference for selecting objects against the background of the underlying surface. The results obtained can be used to create ground-based and aerospace-based radar systems for detecting moving objects and objects with pronounced polarization features.

Casing Integrity Evaluation in Complex Subsurface Intervention Abandonment Wells Using Magnetic Ranging

This paper describes how active and passive magnetic ranging logging used while drilling subsurface intervention wells shows characteristics of the target well casing integrity and damage. Over the course of the development of a novel active magnetic ranging system and through several years of commercial application, data has been collected and analyzed to understand the characteristics of casing damage. This paper explains the methods used in field operations to collect this data. Using the gathered information, various stages of casing damage and poor integrity are shown. Results obtained from active and passive magnetic ranging are presented in the context of identifying casing damage. This is a departure from the standard methods of interpreting the data as it is not focused on locating a wellbore but determining the integrity of the casing. Casing integrity in idle wells is usually understood by conventional logging techniques until there is a restriction or damage on the well. Magnetic ranging logging performed during the intervention to abandon these wells can give an indication to operators of the casing integrity that otherwise would have been unknown without access to the damaged well. This can help optimize subsequent abandonment procedures as well as assist with field planning into the future to mitigate issues stemming from casing integrity and to identify the causes of previously unknown critical casing damage. The paper reports surface experimental data and compares it with two field examples. In the first field example, the passive magnetic interference from a hundred-year-old casing in the offset well caused more than 100000nT deviation from the reference field approximately 1ft away from the offset well, suggesting severe casing damage. The active magnetic signature measured simultaneously approaches zero, pointing to a lack of electrical continuity in the offset casing caused by a complete break. The second field example shows an offset well segment with passive interference of 7000nT in the presence of a stable active magnetic signal at approximately 2ft separation between wells due to possible casing damage without complete separation. The passive interference increases to 14000 nT at deeper depth while the active signal approaches zero due to a complete casing break. Novel application using the data collected by active and passive magnetic ranging techniques is being applied for the understanding of issues related to casing integrity.

Interference in Japanese Learning by First-Year Students of Hospitality Department in State Polytechnic Of Bali

The second-language learning process is often constrained by the influence of mother tongue or first language-Acquisition learners, which is called interference. Interference is principal language irrelevance in bilingual due to one or more language to be introduced or Speech Communication. Based on its phenomenon, students of State Polytechnic of Bali are considered passive interference learners, putting their mother tongue (Javanese and Balinese) elements and Indonesian Language in Japanese consciously or intuitively. This study aims to disclose the type of interference by the hospitality program students for those studying Japanese in State Polytechnic of Bali and explain its factors. The method used is Descriptive Qualitative, which is concerned with taking document field notes and literature Review to represent the real phenomenon of passive Interference types. The population in this study were all students in State Polytechnic of Bali in Japanese class. In contrast, the sample was taken from the results of purposive sampling based on their 100% attendance. There were about 65 first-year or second Semester students in Japanese Class and showed their Interferences. The study results showed that about 75 Passive Interference has commonly occurred in grammatical cases, such as phonetics, morphology, and syntax. Moreover, the occurrence factors of Passive Interference are distinctive Phonetic Features, The Language pattern differences between Mother Tongues (Local Languages) – Japanese, and lack of Japanese Language Proficiency skills and its dictions.

Interference in Japanese Learning by First-Year Students of Hospitality Department in State Polytechnic Of Bali

The second-language learning process is often constrained by the influence of mother tongue or first language-Acquisition learners, which is called interference. Interference is principal language irrelevance in bilingual due to one or more language to be introduced or Speech Communication. Based on its phenomenon, students of State Polytechnic of Bali are considered passive interference learners, putting their mother tongue (Javanese and Balinese) elements and Indonesian Language in Japanese consciously or intuitively. This study aims to disclose the type of interference by the hospitality program students for those studying Japanese in State Polytechnic of Bali and explain its factors. The method used is Descriptive Qualitative, which is concerned with taking document field notes and literature Review to represent the real phenomenon of passive Interference types. The population in this study were all students in State Polytechnic of Bali in Japanese class. In contrast, the sample was taken from the results of purposive sampling based on their 100% attendance. There were about 65 first-year or second Semester students in Japanese Class and showed their Interferences. The study results showed that about 75 Passive Interference has commonly occurred in grammatical cases, such as phonetics, morphology, and syntax. Moreover, the occurrence factors of Passive Interference are distinctive Phonetic Features, The Language pattern differences between Mother Tongues (Local Languages) – Japanese, and lack of Japanese Language Proficiency skills and its dictions.

Characteristics of detecting the coherent system of selection of moving targets during the matching of the parameters of the square channels.

ntroduction. Operation of adaptive system of moving targets selection is considered, which is represented by single intermittent subtractor with coherent accumulator, which is tuned in frequency. System of moving targets selection is made in the form of two quadrature channels, in which high-frequency passive interference and signal from moving object are converted to video frequency with subsequent rejection, accumulation and comparison with threshold level. Setting the task. Investigation of the effect of the inevitable in practice amplitude and phase misalignments of quadrature channel parameters on the detection characteristics of the adaptive selection system of moving targets. Method. Method of complex variable is used, in which passive interference and signal from moving object at input and output of adaptive selection system of moving targets are presented in the form of pair of real components shifted in phase by ninety degrees. Results. Models of passive interference and signal from moving object are presented taking into account possible in practice amplitude and phase mismatches of quadrature channels parameters. The structure of the processing device is shown, which includes a series-connected generator of quadrature components of passive interference and a signal from a moving object, an adaptive cutting filter in the form of a single intermittent subtraction circuit with a frequency-tuned rejection zone, an adaptive coherent accumulator and a threshold device. Expressions are obtained for complex correlation functions of passive interference and signal from moving object at output of coherent accumulator taking into account inevitable amplitude and phase mismatches of quadrature channels parameters. Dependencies of probability of correct detection of signal from moving object against the background of passive interference from value of deviation of transmission coefficients of quadrature channels and phase mismatch of reference voltages for different values of average frequency of spectral density of passive interference are calculated and constructed. Conclusion. Significant dependence of probability of correct detection of signal from moving object on average frequency of spectral density of passive interference, as well as amplitude and phase mismatches of quadrature channels parameters is shown.

SINGLE-CHANNEL PROCESSING OF COHERENT PULSE SIGNALS IN THE PRESENCE OF PASSIVE INTERFERENCE

The processing of coherent-pulse radar signals in the presence of passive interference is considered on the basis of simplified versions of the likelihood ratio. The aim of the work is to synthesize and analyze algorithms and systems for processing coherent pulse signals that are invariant to the Doppler phase shift of the signal over the period of repetition of probing pulses. The integration of the first variant of the simplified truth-similarity relation leads to a system with a single-channel coherent accumulation of pairwise products of the results of adaptive matrix or vector processing. The second variant of the simplified likelihood ratio directly corresponds to the incoherent accumulation of the matrix or vector filter output samples. The structural diagrams of single-channel joint detection-measurement systems based on adaptive matrix and notch filters are presented. The systems were compared by the threshold signal-to-noise ratio using the computer simulation method. It is established that in comparison with the optimal processing system, the losses of the corresponding system due to the single-channel accumulation are an acceptable value.