Ricerc@Sapienza

The paper presents a first attempt to correct the time-frequency reassignment of a multicomponent signal having non separable individual components. In particular, the case of a 2-components signal has been investigated in depth. It has been proved that the integral (along frequencies) of the spectrogram is still a multicomponent signal with specific instantaneous frequencies. As a result, the spectrogram of this signal allows us to disentangle the frequencies and recover the missing information in the non separability region.

In this paper, an evolution law for the modulus of the Short Time Fourier Transform, referred as spectrogram, of a frequency modulated multicomponent signal is proposed. Based on this result, an iterative reallocating method for the enhancement of spectrogram resolution is proposed. Compared to the standard reassignment method, the presented procedure allows us to obtain a time–frequency representation which better localizes the individual modes of a multicomponent signal even in the non separable case.

The focus of this work is on the estimation of the motion parameters of moving targets by means of a dual receive antenna Forward Scatter Radar (FSR) configuration. For this purpose (i) the Doppler signature spectrogram for the single node FSR configuration and (ii) the time delay technique based on the cross-correlation between the signals acquired by a FSR system comprising two different receivers, are both analysed for the joint estimation of the baseline crossing point and of the cross baseline velocity.

The focus of this paper is on the detection of airborne targets and on the estimation of their velocity by means of passive forward scatter radar systems based on the DVB-S as transmitter of opportunity. Results related to an experimental campaign carried out near “Leonardo Da Vinci” airport (Rome, Italy) are shown. Particularly the Doppler signature spectrogram is analyzed for a single node FSR configuration and time delay techniques are analyzed for a multi-static configuration suitable for velocity estimation.

This paper focuses on the exploitation of a single node Forward Scatter Radar configuration for the estimation of the kinematic parameters of targets following a linear trajectory. Accordingly, the target signature extracted from a square law detector followed by a DC removal filter is exploited. A four step processing technique is proposed for the estimation of the main target parameters encoding Doppler rate and derivative of the Doppler rate that are exploited for the extraction of the target motion parameters.