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Studies are carried out to increase the performance of the systems that can perform remote object detection and tracking, to extend the coverage area and to reduce the cost. Many passive radar systems are a good candidate for cost-effective coverage. Passive radar systems are capable of target detection and tracking using commercially available commercial donors without their own transmitter. However, the target detection performance of the systems varies according to the signal characteristics of the commercial transmitter used. While the Doppler resolution of the systems can be changed depending on the integration time, the range resolution varies depending on the bandwidth of the signal. In this article, the effects of multiple consecutive OFDM channel usage on range resolution were investigated in passive radar systems using OFDM signals. First of all, using a software-based radio, an OFDM-based signal was simulated and the range resolution characteristics of this signal were analyzed by self-uncertainty function analysis. Then, sequential channels were added to analyze the self-uncertainty function and changes in range resolution were observed. Since five consecutive channels were used, it was observed that the range resolution could be improved by 42% without losing the correlative properties. [ABSTRACT FROM AUTHOR]

Passive radars are radar systems that do not have a transmitter of their own but can identify and follow targets by using the transmitters located in the environment. The interest in passive radar systems, whose history dates back to 1934, has shown a rapid increase in recent years, as the unit processing cost has decreased and the spread of analog-to-digital converters has widened. The greatest advantages of such systems are that they are cost effective because they do not have any transmitters and undetectable as they work in commercial frequency bands. In this study, the PIRE passive radar system is developed by using software based radio technologies especially for detecting aerial targets. The frequency and time synchronization of the system is provided by the global positioning system (GPS). Additionally, the software based radio (SDR) technology increases flexibility and enables the system to be used with FM radio, GSM, Wi-Fi and TV transmitters. In this study, the hardware and the software components of the developed PIRE passive radar system are introduced, then the potential VHF FM radio transmitter sources are examined, the compliance analysis of these sources is made, and the semi-real time aerial target detection is performed with the developed automatic data acquisition and processing software. Also, the developed software of the PIRE system is shared as open source code. [ABSTRACT FROM AUTHOR]