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Multifunction radars based on active phased arrays are well known and widely studied systems. The concepts of bistatic architecture, conformal array and digital beam forming (DBF) are combined in this paper to define a novel multifunction radar for point defense. The conical shape of the antenna overcomes the significant limitations in the azimuth coverage of 360° of fixed-faces phased arrays due to the beam scanning up to 45°. The usage of separate transmit/receive arrays and the DBF technique adds the operational flexibility and the possibility of multiple simultaneous functions, with an optimal time-energy resources exploitation. After a short description of its technological demonstrator, some significant design trade-off, and operating aspects of the proposed architecture, called d-Radar, are described, showing the main differences with respect to the classical, four faces, and phased-array multifunction radar architecture. It is described how the operating modes can be made more and more similar to a “staring” or “ubiquitous” radar permitting an instantaneous detection and location of short-range, low-elevation targets for sea and ground operations. Finally, some remarks about the resources management and scheduling are shown with the results from a case of study. [ABSTRACT FROM PUBLISHER]

In this paper, the use of regularization methods to solve the location problem in multilateration systems, using Mode-S signals, is studied, evaluated, and developed. The Tikhonov method has been implemented as a first application to solve the classical system of hyperbolic equations in multilateration systems. Some simulations are obtained and the results are compared with those obtained by the well-established Taylor linearization and with the Cramér–Rao lower bound analysis. Significant improvements, for the accuracy, convergence, and the probability of location, are found for the application of the Tikhonov method. [ABSTRACT FROM PUBLISHER]

In this paper, an effective procedure to emplace standard and enhanced mode-S multilateration stations for airport surveillance is studied and developed. This procedure is based on meta-heuristic optimization techniques, such as genetic algorithm (GA), and is intended to obtain useful parameters for an optimal system configuration that provides acceptable performance levels. Furthermore, the procedure developed here is able to evaluate and improve previous system designs, as well as possible system enhancements. Additionally, the design strategies to be used along with the procedure proposed here are fully described. Parameters such as the number of stations, the system geometry, the kind of measurements to be used, and the system accuracy are obtained taking into account the basic requirements such as the Line of Sight, the probability of detection, and the accuracy levels. [ABSTRACT FROM PUBLISHER]

Two localization algorithms for multilateration systems are derived and analyzed. Instead of the classical time difference of arrival (TDOA), a direct use of the time of arrival (TOA) is made. The algorithms work for arbitrary spatial dimensions and overdetermined systems. These derivations are tested in a real-case implementation with simulated data (in particular, the multilateration (MLAT) system installed on the Malpensa Airport in Milan was considered for the MLAT simulation and its possible extension to wide area multilateration (WAM) system was considered for WAM trials). The results are also compared with the present-day algorithms performance, mostly based on TDOA. [ABSTRACT FROM PUBLISHER]