The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper presents a task priority assignment model based on Gaussian Process (GP) multitask classification which resolve the problem of phased array radar resource scheduling in complex electromagnetic environment. According to the work mode and task of the phased array radar, a task model on GP multitask classifier was established and used to preprocess the factors of amount, position of geometry...
High-frequency (HF) ocean radar systems have demonstrated their capability to capture the signal from tsunami currents after the 2011 Tohoku earthquake and tsunami. However, these systems were configured for mapping surface currents in the coastal zones and not for detecting specific patterns of tsunami waves in real-time. The WERA® ocean radar system was optimized for tsunami alerting and installed...
Main purpose of this paper is to outline options of atmospheric pressure determination with help of TDOA method location. The TDOA system uses the ASTERIX data format. There is the exploration of profitable data extraction from ASTERIX data format. Also the principle of atmospheric pressure determination is explained. As a results there are shown derived atmospheric pressure data and its accuracies.
Amplitude and phase imbalance (IQ imbalance) seriously degrades the performance of FMCW radar systems with quadrature demodulator. The non-ideality of the radar signals has two main effects: The single-channel IQ imbalance leads to an image peak in the FMCW spectrum, resulting in wrong detections. The IQ imbalance between channels affects the direction-of-arrival (DOA) estimation, as the array manifold...
Wind turbines WT are planned to be constructed often relatively close to radar systems, e.g. air traffic control, air defense, weather radar. The WT are lossless scatterers on the ground and may affect the radar operation in-acceptably. The dislocation in wind-farms is often tried to optimize by a placement on radials of the radar. This scheme is analyzed theoretically and numerically in this paper...
Millimetre-wave radars at 70GHz are already in mass production for automotive systems but current system aspirations for higher frequencies and for ever-more-cost-effective systems mean that continued advances are required, both in production techniques, and in the development work needed to support them. Particular challenges arise in domains where monolithic integrated circuits cannot (yet) provide...
The potential of the Low THz spectrum for high resolution imaging applications such as automotive radar is described. Outdoor experiments require compact and portable equipment which may be achieved by extending the operation of current battery powered vector network analyzers. The development of a hybrid 670 GHz VNA based radar is described including instrument performance data.
The shoreline is an important part of many cartographic materials. Given the geometric complexity and its length, it is important to use the methods of the automatic extraction. This can be done by using satellite radar imageries. The paper presents an analysis of the automatic shoreline extraction by using selected image processing methods. Extracted shoreline was also assessed in the aspect of the...
This paper presents a system setup based on MIMO OFDM radar that can be used for drone detection and detection of unpiloted aerial vehicles (UAVs) in general. In recent years UAVs have become more and more popular not only for commercial use but also as a private gadget. However, these drones can also be misused as a weapon by criminals, spies and terrorists. Therefore many research is done to be...
Unmanned Aerial Systems (UAS), commonly referred to as drones, are rapidly proliferating bringing about new challenges for security and safety. The reason being their small size and ability to fly low in a highly irregular manner makes them particularly difficult to detect with conventional wide-area surveillance sensors such as a scanning radar. Here, we use staring radar that employs a 2-D antenna...
In this paper, the connection between polarization properties of radar receiveing antennas and deformation/vibration of scattering rain-drops is studied. The mathematical modeling and computer simulation are made to prove that it is possible to influence onto the contribution of a vibration component into the receiving signal by selection of polarization angle of receiving antenna. The results of...
The paper undertakes a problem of tracking radar and AIS fusion in maritime navigation. The focus is laid on target association process, which is the basis for track-to-track fusion. The analysis provides neural approach to association process in which neural network classifies if the association should be stated or not. The paper includes theoretical basics of the proposed approach, as well as numerical...
Pulse sequence analysis is a crucial part in the research on multi-function radar (MFR) behaviours. It is the base for MFR behaviour recognition and prediction to extract radar words accurately from the intercepted radar pulse sequence. The common radar word extraction methods are only based on the time-of-arrival (TOA) of pulses, which perform not well when dealing with the complex signals with multiple...
Carbon Nanotubes (CNTs) and graphene flakes have been of interest since the very beginning due to their extraordinary properties in many aspects. These properties include: high electron mobility in room temperatures, relatively high thermal conductivity and possibly the highest resistance to mechanical stress. Therefore, it is imperative to simulate various scenarios of CNT coated structures. This...
We present a novel method for passive radar that simultaneously reconstructs the scene reflectivity and polarimetric states of stationary targets. Our method uses a spatially sparse distribution of polarimetrically diverse receivers to measure the backscattered signal of a scene illuminated by a source of opportunity. Our data model explicitly accounts for polarization and anisotropy of the target...
In this paper, a 3-D electromagnetic inverse scattering algorithm based on analytical singular value decomposition (SVD) of the scattering integral operator is proposed. The spectral expansion of the dyadic Green's function is employed to derive continuous SVD of scattering integral operator. The analytical formulation of singular values and vectors is straightforward without considerable computation...
This article discusses the possibilities of the location of aircraft via active and passive radiolocation systems. The next part is dedicated to location recording of the aircraft, which uses the general type of Radiolocation Warning Receiver by triangulation method and PG method. Then we examine the analysis of the measured data with the purpose of determination of the location of source radiotechnical...
Mismatched processing of codes with multi-range resolution is revisited. The inverse of a binary code's spectrum is used as the transfer function of the mismatched filter. We calculate the mismatch losses for all combinations of binary codes in the range of code length L≤25 and find codes with very small mismatch loss compared with those of the conventional codes. The Doppler characteristics for various...
Target-Adaptive Matched Illumination (MI) Radars work on targets which can be resolved into multiple discrete scattering centers. Plurality of scattering centers depend on the physical extent and orientation of the target, the range resolution capabilities of the radar and its operating frequency. Increasing the radar range resolution reduces the amount of backscattered energy per discrete range cell,...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.