Study of the effect of wideband sparse frequency signals in UHF passive radar resolution

This paper shows a study about the use of sparse frequency signals for the improvement of passive radar systems capabilities based on DVB-T. The analysis was performed on real signals acquired by IDEPAR, a demonstrator developed at the University of Alcala. Data was obtained upgrading acquisition cards to USRP X310, which have enough bandwidth to acquire groups of DVB-T channels scattered in frequency. A double analysis has been carried out/ to prove the improvement of detector capacity by comparing the initial version of IDEPAR and the updated one. Firstly, the pedestal estimation of the ambiguity function of the acquired reference signal is presented, which is directly related to the signal-to-noise ratio of the system. Secondly, the Range-Doppler maps obtained after the coherent processing of the signals are analyzed. In this case, the average signal to interference ratio along the trajectory of three targets is calculated, as well as the range resolution The results show an improvement in both parameters when increasing the useful bandwidth of the acquired signals.