Sensor Synchronization, Geolocation and Wireless Communication in a Shipboard Opportunistic Array

A wirelessly networked opportunistic digital array radar (WNODAR) is an integrated ship wide digital phased array, where the array elements are placed at available open areas over the entire surface of the platform. The array elements are self-standing digital transmit/receive (T/R) modules with no hardwire connections other than prime power. All control and digitized signals are passed wirelessly between the elements and a central signal processor. This research investigates the problem of integrating the array elements through the design of a wireless synchronization and geolocation network. Phase synchronization of array elements is possible using a simple synchronization circuit. A technical survey of geolocation techniques was performed, and performance curves for the WNODAR operating under different seastate conditions were obtained. Analysis and simulation results suggest that a position location scheme to correct for dynamic effects of hull deflection is not absolutely necessary for an array operating at a VHF or lower UHF frequency. Finally, a design of the demonstration T/R module is proposed. Based on projected communication requirements, the full-scale WNODAR demands a 3.7 Gb/s data transmission rate. The multi-input multi-output orthogonal frequency division multiplexing (MIMO-OFDM) approach has been identified as a promising solution to achieve gigabit transmission rates.