Improved Imaging Model in the Presence of Multiplicative Spatially Extended Cloaking Interference

The paper proposes an improved imaging model in the presence of multiplicative spatially extended cloaking interference. The model take into account the effect of multiplicative masking interference. To simplify the calculations of the image brightness in the distorted region the diagram technique is used. Unlike the known ones, the model takes into account the concentration of the distorting medium in a narrow squat layer, the primary reflection of solar radiation from the upper boundary of the distorting layer and subsequent multiple re-reflections of the transmitted radiation of the visible wavelength range from the earth’s surface and the upper boundary of the distorting medium layer. A technique for finding and taking into account the reflection and re-reflection coefficients of radiation to restore distorted images is proposed. The results of experimental studies are presented. For the experiment, the image of the territory of Iraq during the 2003 "Freedom for Iraq" hostilities was selected. Keywords— image, model, multiplicative, extended cloaking interference, spacecraft, reflection, coefficient

Lipreading in Noise: Cross-Modal Analysis of the Target-Masker Linguistic Similarity Hypothesis

The linguistic similarity hypothesis states that it is more difficult to segregate target and masker speech when they are linguistically similar (Brouwer et al., 2012). This may be the result of energetic masking (interference at the auditory periphery) and/or informational masking (cognitive interference). To provide a rigorous test of the hypothesis and investigate how informational masking interferes with speech identification in the absence of energetic masking, we presented target speech visually and masking babble auditorily. Participants completed an English lipreading task in silence, speech-shaped noise, semantically anomalous English, semantically meaningful English, Dutch, and Mandarin two-talker babble. Results showed that speech maskers interfere with lipreading more than stationary noise, and that maskers that are the same language as the target speech provide more interference than different-language maskers. However, the study found no evidence that a masker that is similar to the English target speech (Dutch) provides more masking than one that is less similar (Mandarin). These results provide some cross-modal support for the linguistic similarity hypothesis, but suggest that the theory should be further specified to address the conditions under which languages that differ in their similarity to the target speech should provide different levels of masking.

DETECTION OF RADAR TARGETS ON THE BACKGROUND OF ACTIVE INTERFERENCE BY THE DETECTOR OF THE POLARIZATION MATTER OF THE SCATTERING

The article discusses the possibility of detecting radar targets moving under the cover of active noise masking interference, acting along the main lobe of the antenna system's radiation pattern, and also using self-covering noise. It is shown that in radar stations with full polarization sounding of the space and measurement of the polarization scattering matrix (PSM), it is possible to synthesize a decisive rule for target detection against active noise-free correlated interference. This synthesis is possible on the basis of the determinant of the polarization scattering matrix, the value of which has the properties of invariance to the form of the polarization scattering vector. The analysis of the determinant of the polarization scattering matrix in the conditions of measuring its elements against the background of active interference makes it possible to identify differences in the values of the determinant under conditions of presence and absence of a target in the volume of space allowed by the radar system. In this case, the value of the determinant becomes the main information feature. A distinctive feature of the detector is the invariance to the form of the polarization scattering vector. The detector synthesis is based on differences in the signals of the secondary and primary radiation, which appear at the output of the PSM meter, namely, on the properties of the determinant of the polarization matrix of the scattering of the object and the signal received from the source of active interference. The purpose of the article is to illustrate the differences in the properties of the polarization scattering matrix at the output of the PSM meter in the presence of active interference and / or a useful signal, as well as the possibilities of using the existing differences in the properties of PSM and their estimates in the presence of active interference for the synthesis of a radar detector.

COMPLEXING IMAGES IN A TWO-CHANNEL OPTICAL-ELECTRONIC SYSTEM AS A METHOD OF REDUCING THE PROBABILITY OF DISAPPOINTING AN AUTOMATIC SURVEILLANCE OF LOW CONTRAST OBJECTS

The paper discusses the work of the correlation algorithm for automatically tracking objects of interest in a two-channel optical-electronic system in a complex background-target environment and the presence of intentional interference. Conditions in which the contrast of the desired object in both channels is negligible but not equal to zero are considered difficult in the paper. Intentional interference refers to masking interference of natural and artificial origin, which helps to reduce the contrast of the object in both channels. By two-channel means an optical-electronic system, which includes channels of the visible and infrared ranges. It is believed that the multi-spectral images of both channels are reduced to a single time and scale, which allows them to be integrated using various methods. The purpose of this paper is to prove that the likelihood of disruption of automatic tracking is reduced when complexing the source images of the visible and infrared ranges, when the contrast of the desired object in both channels is negligible. For research the mathematical apparatus of the theory of random functions and simulation with subsequent statistical data processing are used. It is shown that the probability of disruption, characterized by the ratio of the correlation coefficients of two fragments of images, one of which contains the desired object, and the second not, depends on both the correlation coefficients and the values of their mean square deviations. The simulation shows that the breakdown of tracking occurs both when the mean square deviations of these correlation coefficients are equal, and at their different values, moreover, an increase in their difference increases the probability of a breakdown. The article shows that the likelihood of a breakdown in a two-channel optoelectronic system will decrease when using two channels, compared to working only in the visible or infrared channel. The obtained results substantiate the promise of using image complexing in multichannel systems of automatic tracking of objects in a complex background-target environment and the presence of deliberate interference.