This paper presents an experimental system dedicated for the detection and tracking of small aerial targets such as Unmanned Aerial Vehicles (UAVs) in particular small drones (multirotors). The system was proposed in response to increasing drone popularity and the related threats. The hardware and software parts of the system are covered, including the analogue front-end, FPGA based pre-processing and PC based processing, detection and tracking. Real life trials are described with promising results provided. Further research on the subject is proposed.
23 January 2024 in IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
This paper uses the ISAR imaging method to present real-world tests on 3D radar imaging of non-cooperative air targets. Initially, the fundamentals of 3D ISAR are introduced. This is followed by a discussing of the challenges of obtaining high-quality 3D radar images. An essential feature of the applied method is its basis on the back-projection family of techniques, eliminating the need for iterative image reconstruction. These theoretical concepts are validated using both simulations and real-life signals. The paper also provides insights into the measurement campaign and the signal processing techniques applied to achieve the presented results.
This study presents recent research results obtained by the Warsaw University of Technology, Poland in airborne passive synthetic aperture radar (SAR) imaging using digital video broadcasting‐terrestrial illumination. The main goal of the research was to prove the possibility of passive SAR imaging and its usage for airborne applications. In the study, different signal processing techniques used for passive SAR image creation are discussed in detail, together with an analysis of their computational requirements and implementation possibilities on the computing platforms available on the market. Also, a real measurement campaign is presented showing passive SAR images obtained. Finally, challenges in airborne passive SAR image creation are discussed, showing potential directions of the future development in this field.
We present in the paper results of a generalised micro-Doppler analysis that is suited to high range resolution radar. The target echo energy is here represented in the three dimensional space of time, Doppler, and additionally range, what can provide more information on target micro-motion than the standard micro-Doppler analysis which is performed in the time-Doppler plane. The analyzed signals were recorded with a Ka-band FMCW radar of a high 1GHz bandwidth, which could provide good resolution in range, time and velocity. Here, we present a new method to visualize jointly micro-range and micro-doppler effects of a running man observed on the background of ground interferences.
This paper presents a trajectory determination and optimization method of multirotors equipped with a single-channel radar to obtain 3D Synthetic Aperture Radar imaging. The result is a realistic trajectory that allows to obtain an imaging of the assumed quality in less time than using a multi-pass trajectory. The optimization criteria, in addition to the cross-range resolution, are the Peak Sidelobe Ratio (PSLR), Integrated Sidelobe Ratio (ISLR), and time of flight. The algorithm is based on a realistic motion model of the radar platform. This paper presents all the steps of the algorithm and provides simulation results that show its practical applicability. The advantage of the presented approach over the existing ones is indicated and further research directions are proposed.
Synthetic Aperture Radar (SAR) simulation is widely used for system design, processing techniques development, and mission planning. However, there is no readily available and free framework for SAR raw signal simulation, and many teams and organizations struggle with developing their own simulator from scratch, repeating work that others have done earlier. This work’s purpose is to create a simple, open-source SAR simulation framework that can be used for many purposes and is available for free to everyone. It is a ready tool for SAR processing techniques verification, and thanks to its open-source nature, it fosters collaboration between scientists, both on the simulation and the tool development. Moreover, as the simulation’s underlying mathematics is described in detail in this article, it may serve as a handbook for the radar’s simulation. The simulator was prepared as a stand-alone, multiplatform software working in the Matlab/Octave environment. It is available in an online software repository that allows others to contribute to the original code or to create forks of it. The simulator supports monostatic, bistatic, and multistatic configurations with shadowing. The surface model includes roughness using the modified Phong model, transparency, and complex reflectivity. The antenna pattern is defined with a general two-dimensional model. The article is concluded with the simulator’s demonstrations, including antenna pattern, Doppler shift, and various surface parameters. It is expected that this simulator will be widely adopted and improved by many collaborators.