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Summary form only given.Fundamental tools for radar signal analysis - the matched filter response and the ambiguity function - are briefly discussed and demonstrated on basic signals: LFM pulse, coherent pulse train and a coherent train of LFM pulses. Advanced pulse compression signals and sidelobe reduction techniques are then studied, including: frequency modulation (Costas, NLFM, multi-carrier),...
This paper describes three different continuous wave (CW) radar waveforms which are applied in automotive radar sensors. The radar sensor should be able to detect all objects inside the observation area and to estimate range, radial velocity and azimuth angle simultaneously even in multi target situations. A classical Linear Frequency Modulation (LFM) waveform provides a very high range and velocity...
This paper addresses the effect of wind on target detection performance using a space based radar platform. Forests and lakes are constantly being modulated by wind, which then affects the radar pulse returns by suitably amplitude modulating the temporal returns, thus affecting the Doppler. Billingsley has modeled the windblown autocorrelations using a real symmetric function that is the sum of a...
Bistatic passive radar based on opportunity illuminators such as FM radio, is a hotspot in the domain of radar. The direct/multi-path signals cancellation techniques(DSC) have been discussed by many scholars. These considered algorithms adopt a single-stage adaptive filter processor frame, have sufficient performance in the cancellation of the direct/multi-path interference signals from the selected...
Glaciers in several parts of the world are reported to be retreating and thinning rapidly over the last decade. Radar instruments can be used to provide information on the internal and basal conditions of large and small ice masses. Radars operating in the lower part of the HF spectrum are required for sounding temperate glaciers. Also, low-frequency sounders are useful for measuring thickness of...
Orthogonal frequency division multiplexing (OFDM) radar signals, because of their prominent properties have been recently of interest of many researchers. But the large amplitude fluctuations of the OFDM signals makes it susceptible to system nonlinearities. This paper proposes a new concept of radar coding using OFDM signals which combines orthogonal frequency division multiplexing and phase modulation...
It is efficient to enlarge the radar bandwidth based on multi-band fusion. However, the former research on multi-band fusion did not take velocity into consideration. When the velocity is very high or pulse width is long, ignoring the impact of high speed the range resolution will deteriorate heavily. In this paper the authors develop a new method of forming high resolution range profile of fast moving...
The relation between main-to-sidelobe ratio and Doppler frequency after pulse compression in pseudorandom code (m-sequence) phase modulation CW radar is studied, and the deduction of its mathematical expression is presented. Since the pulse compression with the non-target range gate in m-sequence phase modulation CW radar is a ldquowide-band input, narrow-band output processrdquo, the sidelobepsilas...
For some years, there has been an increasing interest in the use of civilian VHF-UHF opportunity transmitters for radar applications. Among the most different civilian broadcasters, analogue FM and Digital transmitters (like Digital Audio Broadcasters and Digital Video Broadcasters) seem to offer interesting capabilities for radar survey according to their availability and/or to their ldquowiderdquo...
An FPGA-based real-time signal processing unit has been developed to perform Doppler processing in a high resolution CWLFM (continuous wave linear frequency modulated) millimeter-wave radar demonstrator. The article focuses on the strategies followed in order to achieve the required throughput as well as on the measures taken to guarantee coherency. Doppler processing is accomplished to output Range-Doppler...
Bistatic radar has a history which dates back to the very earliest days of radar itself. It has been remarked that interest in bistatic radar has been cyclic, with a period of about fifteen years. Numerous experimental systems have been built and evaluated, though rather fewer operation systems. The purpose of this paper is to present and discuss recent developments that indicate that bistatic systems...
In this paper, we study the resolution properties of linear FM pulses (chirps). Based on the ambiguity surface properties of chirp pulses, we propose a transmission strategy and a processing algorithm that has better delay-Doppler resolution than traditional matched filtering. It is shown that the improvement in resolution is accompanied by a small degradation in detection performance.
Previous work has addressed adaptive radar waveforms that may be designed to be spectrally orthogonal to a received, in-band, time-varying, interference environment. This paper introduces a different adaptive waveform technique whereby a standard LFM waveform is modified to minimize its adjacent-band interference to other spectral users. In addition, results are shown for in-band and/or adjacent-band...
This paper describes the design, development and test of a passive covert radar (PCR) exploiting a single non cooperative frequency modulated (FM) commercial radio station as its transmitter of opportunity. The system has been conceived in order to detect low flying and low radar cross section (RCS) targets even in disturbed and hostile electromagnetic environments. Preliminary measurements of the...
In a world, where terrorism is threatening human life in particular that of those forces and civilian personnel who are involved in peace keeping and peace enforcing missions, the defence against snipers is a necessary safety demand. For this purpose sensor systems based upon various principles are in use and still under development. Among those acoustic and electro optical sensors are the most common...
In this paper we evaluate the target detection performance improvement of a multi-frequency approach for FM radio based passive bistatic radar. Specifically, we consider the high diversity of the FM radio signals received over different carrier frequencies spanning the 88-108 MHz band since it represents the basis for the request of a multi-frequency operation. The joint exploitation of the waveforms...
In previous work, frequency diversity has been shown to be an effective means of exploiting distributed radar apertures. Frequency diversity allows for each transmission to be isolated and processed independently of other frequencies. This paper presents an efficient implementation of a frequency diverse distributed radars, based on orthogonal frequency division multiplexing (OFDM), a concept borrowed...
This paper describes an approach to high range resolution (HRR) by means of stretch processing by digital deramping. This approach offers advantages that are common for stretch processing, as a moderate data rate for signal processing in the presence of a high bandwidth waveform. In contrast to conventional analogue processing, deramping is realized digitally. The approach of digital deramping offers...
The paper describes the results achieved at the INFOCOM Department of the University of Rome ldquoLa Sapienzardquo on passive bistatic radar (PBR). The developed adaptive signal processing techniques are introduced for: improved disturbance cancellation, multipath removal, and multifrequency target detection. The development of experimental wide-band PBR prototypes is described, as opposed to single...
MTI radar systems and signal processing algorithms may be made more efficient if a wide range of perfect and background distorted Doppler signatures could be made available to test system hardware and algorithms. This paper addresses emulators of moving vehicle Doppler signatures. Measured Doppler spectra of tracked and wheeled vehicles are used to guide the development of moving target emulators...
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