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International audienceThis paper presents an opportunity to cancel range ambiguities in synthetic aperture radar (SAR) configuration. One of the limitations of SAR systems is the range ambiguity phenomenon that appears with long delayed echoes. The reflected signal corresponding to one pulse is detected when the radar has already transmitted the next pulse. Thus, this signal is considered as an echo from the next pulse. This paper investigates the opportunity of coding the transmitted pulses using an orthogonal frequency-division multiplexing pulse. The results show that coded-OFDM signals outperform conventional chirp signal and make it possible to relax constraints placed upon the pulse repetition frequency

This paper deals with the ability to perform radar cross-section (RCS) pattern measurements within reverberation chambers (RCs). The characterization principle is based on the estimation of the back-scattered field from the target at a farfield distance and takes advantage of the diffuse field within the RC. A frequency sweep of scattering parameters is achieved in presence and absence of the target installed on a rotating mast and the pattern is retrieved from these measurements. This paper explains the underlying theory and discusses the impact of several parameters on the performances. This includes the effect of the stirrer rotation which enables to enhance the dynamic range of the measurements. Experiments in two different RCs show the relevance of the proposed approach for RCS extraction and confirm the theoretical analysis.

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