Differential Lobing in Sidelobe Suppression Systems

The sidelobe suppression function in the secondary surveillance radar system is analyzed when separate main and control antenna are used. Their vertical lobing structures are not matched with each other, so a differential lobing pattern comes out whose maxima and minima are enveloped by smooth curves depending on vertical displacement of phase centers and horizon cutoff rates. The developed analysis provides a method for the evaluation of the system performance for any antenna configuration and for the determination of design guidelines.     

Noisy Feedback in a Binary Sequential Communication Scheme

The effects of a noisy feedback channel on a communication system with the decision and information feedback proposed as by Mancianti et al. are described. Expressions for the expected transmitted energy per symbol, expected decision time, and receiver's error probability are derived in terms of the error probability Pef over the noisy information channel. Because of the complexity of exact calculations, we have analyzed in detail only the case of two repetitions per symbol. Then, in order to give a general picture of the system performance, the asymptotic behavior has been examined.     

Algorithms for Spatial Laser Beacon Acquisition

The pointing system for optical data transmission over unguided channels uses a return beacon from the receiver back to the transmitter to aid the reciprocal alignment of the two stations. We concentrate on CW or pulsed-beacon acquisition with array detectors in the presence of extended clutter in addition to background and receiver noises. Acquisition in the presence of a single interferer (jammer) is also considered. A maximum likelihood (ML) approach is used when preliminary scene information is available. In the case of unknown scenario, a picture-picture subtraction algorithm is considered for the pulsed laser. Performance is evaluated in terms of probability of an acquisition error for Poisson statistics of the photodetector output.     

Detection and Time-of-Arrival Estimation of Received Pulses in Radar Beacon Systems

This paper is devoted to the analysis of the detection and time-of-arrival estimation process of the signalling pulses in a sweep time of a radar beacon system. A simplified model of the detector/estimator is worked out to evaluate pulse detection and false-alarm generation. Finally the performances of a previously proposed video-pulse quantizer are derived in the absence of interference, whose effects are examined in some critical conditions.