Stanislav Hristov

FSR velocity estimation using spectrogram

This paper focuses on the estimation of target motion parameters in forward scatter radar. A new method based on the use of the Doppler signature spectrogram has been investigated. This allows a rough estimation of target motion parameters even in the presence of significant clutter, when the Doppler signature cannot be used to extract accurate kinematic information. The spectrogram characteristics change depending on targets speed, crossing angle and crossing point, this will be shown in order to explain how it is possible to estimate kinematic information analyzing the spectrogram trend. The performance of this new method is analyzed at the initial stage of the research.

Passive Multifrequency Forward-Scatter Radar Measurements of Airborne Targets Using Broadcasting Signals

This paper demonstrates the feasibility and effectiveness of forward-scatter radar (FSR) target detection based on the signals of opportunity made available by standard radio and TV broadcast transmission stations. This passive FSR (P-FSR) operation is obtained by means of a simple and robust correlation process based on self-mixing. This is shown to be very effective in extracting the characteristic FSR modulation produced by airborne targets, from the signals received from frequency modulated, digital audio broadcasting, and digital video broadcasting transmitters of opportunity. Target detectability is discussed as a function of the carrier frequency, the target size, and its height at the baseline crossing. Experimental results are shown using a wide variety of sources of opportunity, target types, baselines, and receiver configurations. The target signatures obtained from the different illuminators are compared and ways of extracting the kinematic parameters of the aircraft are discussed. This validates the claimed effectiveness and robustness of the P-FSR with the presented processing scheme.

Target Shadow Profile Reconstruction in ground-based forward scatter radar

This paper concerns with the practical aspects of the target profile reconstruction in a single-node ground-based forward scatter radar (FSR) system. Modelling approach for simulation of the target signal return and procedure of the target profile reconstruction are discussed. Experimental set-up and measurements are described. For the first time the reconstructed profiles of three different cars measured in real outdoor environment are demonstrated. The performance of the reconstruction is analysed at this initial stage of the research, operational regimes and conditions to deliver robust and interpretable profile outline are discussed.

Passive Maritime Surveillance Using Satellite Communication Signals

In this paper, the feasibility of a bistatic passive system for maritime surveillance and marine navigation is considered based on the communication satellite constellation Inmarsat as a source of illuminating signals. A power budget analysis is detailed for Inmarsat signals, considering both the reference and the radar channels. The effect of sea clutter is also examined. It is shown that relatively poor range resolution can be improved if the available communication channels are combined to improve the bandwidth, a process that also improves the sensitivity. For the first time, detection and preliminary bistatic range-Doppler tracking are presented for a representative maritime target.

Design and Validation of a Passive Radar Concept for Ship Detection Using Communication Satellite Signals

In this paper, the feasibility of a bistatic passive maritime surveillance system based on the use of communication satellites as illuminators of opportunity is considered and confirmed experimentally. A theoretical comparison of the characteristics of a radar using Inmarsat and Iridium signals as donors has been performed. The procedure of enhancing the range resolution by coherently combining available scarce active communication channels in the frequency domain is presented with the example of the Inmarsat I-4 satellite broadband global area network signals. Parameters affecting the performance of range-Doppler mapping of a target are investigated based on the analysis of the ambiguity function of the combined signals. An experimental set-up with a stationary passive receiver designed for acquisition and processing of Inmarsat signals is presented and the results are shown. The detection and estimation of radial velocities by reflected Inmarsat signals are presented for the first time. The detected maritime targets ranged in size from a large passenger ferry to a small boat. The potential limitations of the concept are outlined, together with ways to overcome them.