Piotr Krysik

A concept of GSM-based passive radar for vehicle traffic monitoring

In this paper the passive radar used as a transmitter of opportunity GSM BTS stations has been proposed for vehicle traffic monitoring. The paper presents a feasibility study on using GSM signals for traffic control in different environments including urban areas, highways and small agglomeration roads. The initial analysis shows that such system can be successfully used to extract traffic parameters such as the average speed of vehicles and road capacity. Additionally, the presented GSM passive radar concept for vehicle traffic monitoring has been successfully verified using real-life signals recorded during a measurement campaign carried out at the Warsaw University of Technology.

Velocity measurement and traffic monitoring using a GSM passive radar demonstrator

The paper presented an idea for a new potential civilian application for passive radar utilizing a GSM transmitter as the illuminator of opportunity. The concept presented has been verified via the processing of the data recorded during a measurement campaign carried out in a real operational scenario. The results presented in the paper show that a GSM-based PCL system can be used successfully in the future as a new system dedicated to speed control and traffic monitoring, both in urban areas and on small roads and highways. The results presented in the paper show that the system is able to simultaneously distinguish different-sized objects, characterized by different RCSs, as in the example of the truck and cyclist. This result shows the high potential of the proposed system.

Passive bistatic SAR imaging — Challenges and limitations

In this article, a concept of passive bistatic SAR (PB-SAR) imaging using a spaceborne SAR radar transmitter of opportunity is presented. This was proposed for the first time in the beginning of this century by Krieger et al and Griffiths et al. Because passive imaging is completely covert and relatively cheap, as it does not require its own transmitter, and the rapid growth of the computational power of processors has made it possible, the topic has attracted the attention of many research institutes. Recently, several bistatic radar experiments have been carried out using ground stationary receivers and spaceborne illuminators, and the results have shown new capabilities of SAR imaging. In most of these trials, cooperative illuminators were used and placed on satellite platforms developed by the country conducting the experiment, means that the receiver has exact a priori information about the transmitters parameters (e.g., carrier frequency, signal parameters, chirp duration, pulse repetition frequency [PRF], etc.). To obtain a passive SAR image when the parameters are roughly known, additional techniques for signal analysis and parameter estimation have to be applied, which make the processing more sophisticated. In this article, the challenges and limitations of the PB-SAR imaging are discussed, and the differences in the signal processing chain in mono- and bistatic configurations are indicated. Finally, the recent results of real passive SAR images are presented. The results were obtained by the Warsaw University of Technology (WUT) in 2013, using their passive radar demonstrator mounted on the ground. As the transmitter of opportunity, the TerraSAR-X satellite was used.

FMCW SAR based on USRP hardware platform

The paper presents a concept of using universal software radio peripheral (USRP) as a hardware platform for frequency modulation continuous wave (FMCW) synthetic aperture radar (SAR). The concept presented has been successfully verified through several measurements in the laboratory, as well as in real scenarios where the USRP-based SAR radar was mounted on a ground moving platform and SAR images of the surrounding area were created. The results obtained show that USRP hardware can be used successfully in low cost SAR projects, as well as a system for testing FMCW analog front ends. Moreover, due to its small size the proposed system can be used as a direct digital synthesizer (DDS) and analog digital converter (ADC) for low cost systems dedicated for small ultralight aircrafts or medium size unmanned aerial vehicles (UAV).

Detection of fast maneuvering air targets using GSM based passive radar

This paper presents the results of the detection of fast maneuvering air targets (e.g. air fighters) using GSM based passive radar. The results were obtained during the measurement campaign carried out by the Warsaw University of Technology on the Polish coast of the Baltic Sea. The main goal of the trials was to verify the possibility of the utilization of a GSM passive radar as a short range air surveillance radar. The results show a broad range of the GSM-based passive coherent location technology capabilities in that area.

Ground-based mobile passive imagery based on a DVB-T signal of opportunity

A new approach to passive bistatic radar imaging using DVB-T signals as illuminators of opportunity is presented. The concept has been verified using ground based mobile platforms as a radar receiver carrier. The paper presents an algorithm description and its verification using both simulated and real data gathered during an outdoor measurement campaign.

Bistatic ground-based passive SAR imaging using TerraSAR-X as an illuminator of opportunity

The paper presents an experiment with bistatic passive SAR imaging in a scenario involving the TerraSAR-X satellite as an illuminator of opportunity and a static, ground-based receiver. The experiment was performed during a measurement campaign carried out by the Warsaw University of Technology in July 2012. In the paper the design of an X-Band receiver system and the bistatic SAR processing used for imaging are described. Also the resultant images produced for different polarizations of transmitted waves are included.

Identification of helicopter rotor parameters using multistatic passive radar

This paper presents results of the analysis of a helicopter echo in a passive radar based on a DVB-T signal. It contains a theoretical study of the main rotor blade echo in a multistatic configuration. The simultaneous use of more than one transmitter-receiver pairs enables estimation of additional parameters of the rotor. By processing real data, the authors have shown the possibility of estimating the radial velocity and the number of main rotor blades of a helicopter. Parameters extracted by the analysis of a helicopter echo can be further used for target classification.

Towards a mobile low-terahertz SAR imaging radar — Limitations and prospects

In this paper a system for radar measurements using a low terahertz frequency band is presented. The architecture of the system is briefly described and some preliminary results obtained with the developed system are attached. A concept to rebuild this system for outdoor radar experiments is presented and the design process described, with an emphasis on the design challenges. Design choices regarding signal generators and recorders, analog intermediary circuitry, and the navigation system are discussed in this paper.

Verifcation of a SAR processor by arbitrary generation of simulated beat signal

The paper describes the idea of verification of a Linear Frequency Modulation - Continuous Waveform (LFM-CW) Synthetic Aperture Radar (SAR) processing system operating in real-time by arbitrary generation of the beat signal. The system under the test collects the beat signal from the arbitrary waveform generator, instead from the radio frequency (RF) frontend, and produces the image. Beat waveforms are prepared previously in a SAR simulator and may correspond to a variety of mission scenarios - from single scatterers and linear platform movement to complex urban scenes and perturbed trajectories of the radar carrier. With such approach the digital and software part of the SAR processor can be examined very simply and efficiently at system level.