Introduction. Synthetic aperture radars (SAR) are important components of aviation-based systems for remote sensing of the Earth. The current level of such systems allows simultaneous radar surveys in several frequency ranges. Such surveys require complexing of the images formed in each of the frequency channels, which task is yet to be resolved.
Aim. To review the formation principles and methods for joint processing of images using space and aviation-based multi-band synthetic aperture radar systems.
Materials and methods. The methodology of systems analysis, involving the integral stages of decomposition, analysis and synthesis, was used. Decomposition of integrating multi-band radar images was performed considering the effect of various factors on the characteristics of radar images in different frequency ranges. Such factors include the principles of radar imaging, issues of radar images of multi-band synthetic aperture radars with real characteristics, and complexing levels.
Results. According to the classical systems approach, the results of review and analysis are corresponded by appropriate conclusions on the shortcomings of each decomposition element and the synthesis of a proposal for achieving the goal. It was shown that joint processing of multi-band radar images can be carried out at the levels of signals, pixels, features and solutions, as well as their aggregates. Each approach is characterised by its shortcomings, which impede implementation of full integration of multi-band radar images without loss of information, which is due to the absence of information redundancy of radar images, compared to, e.g., optical images.
Conclusion. Recommendations on the application of a particular method and the synthesis of a system for radar complexing images based on the texture-fractal approach were formulated. Directions for further work meeting all the requirements for completeness, reliability and information content of remote sensing of the Earth were outlined.

Introduction. Automotive radars are the main tools for providing traffic safety. The development of such radars involve a number of technical difficulties due to the manufacture of high-precision extremely high-frequency (EHF) printed circuit boards. To facilitate the process of creating such devices, the existing algorithms for radar information processing should be debugged using prototypes from manufacturers of mm-band transceivers. However, the parameters of such boards are not known in advance, and the actual operating conditions of the as-produced automotive radars raise new challenges to target tracking algorithms. Therefore, checking the performance of such boards is a relevant research problem.
Aim. To evaluate the performance of a millimeter-wave automotive radar prototype and to test target tracking algorithms using this prototype.
Materials and methods. An original target tracking method was used, which considers the constraints on the use of additional data sources about the radar carrier movement.
Results. An experimental performance evaluation of a 77 GHz automotive radar prototype was carried out. The effectiveness of primary processing for the target class “vehicle” in the millimetre range was checked. Original algorithms for target tracking were proposed and tested.
Conclusion. The obtained results show that the prototype board of a transceiver chip is capable of testing tracking algorithms without creating an own automotive radar prototype. Thus, the developmental process can be significantly shortened. Moreover, after creating a hardware solution, the developer obtains a reference device to test and configure an own product without using extremely expensive and rare EHF equipment.

Introduction. Modern vehicles are equipped with radars, which serve as the main sensors of driver assistance systems detecting objects in all weather conditions. Antenna arrays (AA) are the most common type of radar antennas. The coefficient of mutual coupling between adjacent antenna channels has a significant effect on the formed radiation pattern (RP) of an AA. This aspect is important for achieving the required values of gain and side-lobe level (SLL). This article analyses the effect of the proposed design solutions on the main parameters of an automotive radar AA, in particular, on the mutual coupling coefficient between the channels and the SLL of the DP.
Aim. To develop an optimal approach to constructing an AA topology in terms of reducing the level of mutual influence of adjacent array channels and obtaining a DP with specified characteristics.
Materials and methods. To achieve the required parameters of the designed AA topology, the coplanar and microstrip lines were calculated using the finite element method and shield models.
Results. An electrodynamic modeling of a millimetre-wave AA was carried out. The effect of coplanar transmission lines on the RP was shown. The features of applying shielding elements in the AA structure were investigated. Antenna patterns were obtained for both an AA designed based on coplanar transmission lines and that based on the use of shields. The conducted comparative analysis determined the parameters of the substrate optimal for achieving a better level of decoupling between adjacent antenna channels. The values of AA RP obtained during modeling were presented.
Conclusion. The use of coplanar transmission lines can significantly reduce the SLL of the DP in the elevation plane. When implementing the module structure of an array (using of sub-arrays), the power dividers are realized. In this case, instead of coplanar lines, it is advisable to use specific microstrip constructions covered with shielding surfaces. In this case, the formation of a given amplitude-phase distribution over aperture is possible. A comparative analysis of the AA topologies with different substrates was carried out with the purpose of achieving improved decoupling. The obtained values of the coefficient of mutual influence of adjacent array channels correspond to those of modern AA of automotive radars. The methods of reducing the parasitic radiation of transmission lines were considered. The AA RP obtained via electrodynamic modeling were presented. The use of a thin substrate with a higher dielectric constant makes it possible to improve the AA characteristics.

Introduction. An important part of an automotive unmanned vehicle (UV) control system is the environment analysis module. This module is based on various types of sensors, e.g. video cameras, lidars and radars. The development of computer and video technologies makes it possible to implement an environment analysis module using a single video camera as a sensor. This approach is expected to reduce the cost of the entire module. The main task in video image processing is to analyse the environment as a 3D scene. The 3D trajectory of an object, which takes into account its dimensions, angle of view and movement vector, as well as the vehicle pose in a video image, provides sufficient information for assessing the real interaction of objects. A basis for constructing a 3D trajectory is vehicle pose estimation.
Aim. To develop an automatic method for estimating vehicle pose based on video data analysis from a single video camera.
Materials and methods. An automatic method for vehicle pose estimation from a video image was proposed based on a cascade approach. The method includes vehicle detection, key points determination, segmentation and vehicle pose estimation. Vehicle detection and determination of its key points were resolved via a neural network. The segmentation of a vehicle video image and its mask preparation were implemented by transforming it into a polar coordinate system and searching for the outer contour using graph theory.
Results. The estimation of vehicle pose was implemented by matching the Fourier image of vehicle mask signatures and the templates obtained based on 3D models. The correctness of the obtained vehicle pose and angle of view estimation was confirmed by experiments based on the proposed method. The vehicle pose estimation had an accuracy of 89 % on an open Carvana image dataset.
Conclusion. A new approach for vehicle pose estimation was proposed, involving the transition from end-to-end learning of neural networks to resolve several problems at once, e.g., localization, classification, segmentation, and angle of view, towards cascade analysis of information. The accuracy level of end-to-end learning requires large sets of representative data, which complicates the scalability of solutions for road environments in Russia. The proposed method makes it possible to estimate the vehicle pose with a high accuracy level, at the same time as involving no large costs for manual data annotation and training.

Introduction. In the case of a nonuniform (NU) design of the antenna elements (AEs) of the receiving antenna array (AA), the antenna pattern (AP) features sidelobes (SL) with a significantly higher noise level than acceptable values. Under low signal-to-noise ratios (SNR), this noise leads to angular coordinate measuring errors thus worsening the statistical accuracy characteristics (ACs) of the signal. It is of relevance to construct the ACs of angular coordinates when a modified parametric Burg method (BM) is applied to spatial reflected signal processing in a transportable decametre range radar (DRR) with a nonuniform array (NUA) and linear accuracy characteristics.
Aim. To analyse the statistical ACs of angular coordinate objects when using a modified BM for spatial reflected signal processing in a DRR with a linear NUA, in which AEs are located with a random step in the range from λ/2 to several λ, where λ is the operating carrier wavelength.
Materials and methods. Statistical ACs were constructed by computer modelling in the MatLab software, the reliability of which was confirmed by conventional discrete Fourier transform methods, as well as by comparing the obtained ACs with asymptotic bounds, including Cramer-Rao bounds.
Results. The possibility and conditions of using a modified parametric BM for estimating the azimuthal coordinates of reflected radar signals were determined for the case of a nonuniform design of the over-the-horizon DRR receiving AA AEs. Statistical ACs were obtained and compared with the asymptotically optimal ACs of the maximum likelihood estimations corresponding to the uniform AE design.
Conclusion. The obtained results confirm the suboptimality of the BM modified for signal processing in the NUA at a random AE spacing step in the range from λ/2 to 2λ, making it applicable for use in transportable DRRs.

Introduction. The analysis of the current state and prospects of space-based radar surveillance tools is important for determining their functions in global aerospace information systems, which aim to monitor air and space, as well as the Earth's surface. Radar surveillance information is used for the purposes of economic analysis, environmental monitoring, mineral search, emergency monitoring, detection and recognition of specified object s at sea and on land, as well as for ensuring national security. In this regard, it is of relevance to develop methods for preliminary assessment of the resolution capacity of novel high-precision onboard radar systems installed on a spacecraft, considering their main technical characteristics, the parameters of the spacecraft movement and the influence of the atmosphere. A priori estimation of spatial resolution values requires a method for calculating the corresponding indicators meeting the required quality of the synthesized radio holograms.
Aim. To derive mathematical dependencies and logical rules allowing a priori estimation of the spatial resolution of radar images obtained by the onboard equipment of a radar complex.
Materials and methods. Analytical methods were used to determine the resolution error of onboard radar systems with a synthesized aperture in the lateral (azimuthal) direction and range, as well as the theory of radar signal processing.
Results. A comparison of the experimental and analytical data on the resolution capacity of an actual radar system confirmed the validity on the proposed method. The developed methodology was used to determine the procedure of calculating the error when estimating the resolution capacity in terms of azimuth and range.
Conclusion. The proposed method can be used for both designing novel radar systems and comparing existing radar complexes, depending on the resolution requirements.

Introduction. Porous silicon (PS) and materials on its basis are of interest for application in nanoelectronics, targeted drug delivery and advanced gas sensors. In addition, PS-based nanostructures are promising as filters in fibre-optic communication systems, since conventional thin-film deposition filters possess sidebands in their operating range thus requiring high vacuum for nanometer-thick coatings.
Aim. To develop optical band-stop filter prototypes based on composite magnetic nanoparticles and the effect of localized surface plasmon resonance (LSPR) in an array of silver nanoparticles located on the PS surface.
Materials and methods. The development and synthesis of nanostructures for the creation of filter prototypes. The double differentiation method in conjunction with Mie absorption theory was used for processing and analyzing the prototypes attenuation characteristics.
Results. Two prototypes were developed. An analysis of the attenuation characteristics of a prototype based on SiO₂ matrix functionalized by Fe_mO_n indicated that the parameters of the detected absorption bands depend on the size of Fe_mO_n nanoparticles. The attenuation characteristics of the LSPR-based prototype contain two absorption bands. The center wavelength value in the band caused by LSPR in the array of silver nanoparticles, close to spherical, is 367.5 nm. Excitation of LSPR in silver quantum clusters, manifested by the appearance of the corresponding band, occurs at a wavelength of 265.5 nm. The suppression in each of the bands can be controlled by changing the parameters of the PS matrix synthesis.
Conclusion. Despite the disadvantages, e.g. a relatively low accuracy in setting the center wavelength, as well as certain difficulties concerned with reducing the unevenness in the absorption band, the obtained prototypes surpass existing analogues and are prospective for the development of compact analysis and diagnostics systems in a wide energy range.

Introduction. In this article, the basic principles of ecological monitoring were considered, and the possibilities of constructing sensor systems were analysed. It was proposed to use the NB-IoT low-energy telecommunication standard as a basic wireless protocol for ecological system development, which ensures effective communication of network devices. A prototype of the system was constructed, and algorithms for receiving and transmitting signals were simulated.
Aim. To construct a prototype of a transceiver based on the NB-IoT standard and perform its simulation. To utilize digital twin in MatLab to create the proposed system.
Materials and methods. The prototype was constructed using the Xilinx Zedboard evaluation board and transceiver on AD9361 chip, and the simulation was performed using the MatLab 2010 software package.
Results. The results of the simulation in the channel with the additive white Gaussian noise (AWGN) were obtained, and the level of the detected synchronization signals of the NB-IoT standard was determined. The receiver and transmitter of the NB-IoT standard were implemented on the Xilinx Zedboard evaluation board. The timing simulation results show that the designed system can be tested in a real environment. The power consumption and resource utilization of the constructed wireless sensor network prototype unit were determined.
Conclusion. The results obtained via the simulation process show that the designed prototype of the communication system works correctly, and the produced signal meets all the requirements of the NB-IoT standard. The results can be used for creating a domestic manufactured, specialized integrated chip for data units of ecological monitoring systems.