Adam Kawalec

Adaptive Forming of the Beam Pattern of Microstrip Antenna with the Use of an Artificial Neural Network

Microstrip antenna has been recently one of the most innovative fields of antenna techniques. The main advantage of such an antenna is the simplicity of its production, little weight, a narrow profile, and easiness of integration of the radiating elements with the net of generators power systems. As a result of using arrays consisting of microstrip antennas; it is possible to decrease the size and weight and also to reduce the costs of components production as well as whole application systems. This paper presents possibilities of using artificial neural networks (ANNs) in the process of forming a beam from radiating complex microstrip antenna. Algorithms which base on artificial neural networks use high parallelism of actions which results in considerable acceleration of the process of forming the antenna pattern. The appropriate selection of learning constants makes it possible to get theoretically a solution which will be close to the real time. This paper presents the training neural network algorithm with the selection of optimal network structure. The analysis above was made in case of following the emission source, setting to zero the pattern of direction of expecting interference, and following emission source compared with two constant interferences. Computer simulation was made in MATLAB environment on the basis of Flex Tool, a programme which creates artificial neural networks.

Applying the distance and similarity functions to radar signals identification

One of the principal functions of the ESM/ELINT system is gathering basic information from entire electromagnetic spectrum and its analysis. In most cases, based only on primary features of incoming radar signals, the modern electronic intelligence system cannot recognize the different devices of the same type or class. A very important role is played by Measurement and Signature Intelligence (MASINT). The process of Specific Emitter Identification (SEI) based on extraction of distinctive radiated emission features and final emitter identification based on ldquothe knowledge-based approachrdquo [1, 2], generally is not enough to identify detectable radar emission.

Target Detection Using HF Radar Data

High frequency (HF) radar systems have a potential to detect targets which are located beyond the optical horizon on the sea surface. Unfortunately sea clutter may be strong enough to prevent such detection. In this work we present results of applying space-time adaptive processing (STAP) to this problem. Real, registered signals were used for numerical experiments.

Space-Time Adaptive Processing analysis for the moving target on the sea surface indication purpose

Space-time adaptive processing (STAP) can improve target detectability in a presence of a ground clutter for airborne radar. Ground clutter echo has a wide spectrum as a result of the radar platform (airplane or satellite) motion. To reject clutter echo and preserve target echo, STAP employs antenna array. Simultaneous filtering in both spatial (angle) and frequency domain can improve performance. In this paper we propose a new application of STAP. Assuming an antenna array standing on a sea shore, the objective is to detect targets on the sea surface. Unfortunately sea clutter has different statistical properties compared to airborne clutter. As a consequence, basic STAP algorithm is not optimal in any sense. Future research will face the problem of evaluating performance of STAP applied to sea clutter. We hope to develop a new algorithm that can perform better in the presence of sea clutter.

Wide-band SAW dispersive filter with a flat amplitude response

Abstract It is shown, that a dispersive delay line of a flat amplitude-frequency characteristic in the passband can be synthesized by using the method proposed in reference 1. Such a delay line can be applied in a chirp pulse compression system that exhibits lower side-lobe sensitivity to the Doppler frequency shift of the radar signal.

Application of CUDA computing technology in radar digital signal processing

This article describes CUDA computing architecture, as an effective tool for digital signal processing in radar systems. The goal of this article was to present results of programs that implemented different types of signal processing. In this article authors also presented different methods of increasing the efficiency of the implemented algorithms.

The instability measurements for the unmanned aerial platform as a radar carrier

The paper presents the testbed for the UAS instability measurements. The testbed consists of the aerial vehicle of the miniUAV class. The airplane is equipped with the sensor suite built upon several sensing devices: gyroscopes, accelerometers, magnetometers, GPS receiver and pressure sensors. The data from the sensors is combined in the on-board sensor fusion processor and then transmitted to the ground control station. The aerial vehicle that was acting as a carrier platform is a regular UAV being an equipment of one of the European armies. The testing results show the flying platform instabilities that can be expected during the synthetic aperture radar mission onboard the miniUAV airplane. Several measurements have been taken and the instability characteristics are presented and discussed. The aim of such measurements is to find out the starting point for design of the stabilized platform to be built onboard the UAV. The platform requirements drawn from the presented measurements are taken into account in the review of the possible stabilization solutions. The stabilized platforms were discussed with the respect of the SAR requirements.

Effect of integration time on detection performance of MTI and STAP algorithms in HF radar

Surface wave over the horizon radar systems have a potential to detect targets falling far beyond optical horizon. Unfortunately, first and second order clutter scattered from the ocean surface, in combination with interferences, can prevent successful deployment of such systems. In this paper we compare different adaptive MTI and space-time adaptive processing algorithms applied to the surface wave high frequency radar system data. The aim of the experiments was to detect small targets (20-30 m long) at distances about 50 km. Radar system used in the experiments is an oceanographic, surface-wave, high-frequency system WERA, designed to perform continuous monitoring of sea currents and waves. System used in this research is located at the east coast of France, in Brittany. Main task of the system is to provide continuous, real-time information about currents and waves in the English (La Manche) Channel entry area, where heavy ship traffic is present.

Evaluation of a low-cost microUAV platform for sensor suite

The paper presents the idea of a low-cost micro sized unmanned aerial vehicle. Its main purpose is being an aerial platform for a sensor suite. The sensor suite may consist of TV camera, FLIR, ESM, SAR and a set of position telemetric sensors as a GPS/INS or artificial horizon. The paper discusses the specific demands of each kind of sensor type and presents the technology demonstrator which is particularly useful for preliminary tests.

Integration of passive coherent radar system into the passive TDOA system

One of the ways of passive coherent radar system integration into the passive TDOA system is considered. Generalized algorithm of the objects location estimation on their radiation of the onboard radio technical systems and in the field of highlighting by the different purposes ground based transmitters with a priory known and unknown coordinates is shown.