On the Imaging of Large Antenna Array Navigation Systems

抄録

This contribution discusses the imaging of large antenna array navigation systems by means of near-field measurements. Examples for such navigation systems are the instrument landing system (ILS) and the Doppler VHF omnidirectional radio range (DVOR). In this context, imaging means the determination of individual array antenna amplitudes and phases with near-field measurements and a corresponding prediction of the far-field radiation characteristics according to required specifications of flight inspections. Near-field measurement results of a large ILS antenna array are presented, and fundamentals are explained with numerical simulations. In particular, a simple simulation scheme allows the investigation of basic measurement requirements and errors that are essential for the later application. This work is part of the Navant-NG II (navaid antenna characterization – next generation) project dealing with near-field inspection techniques using a unmanned aerial vehicle. From the academic point of view, this contribution summarizes the fundamental issues and probable approaches for solutions of such imaging techniques, which are a mathematical ill-conditioned problem that exceeds the current state-of-the-art near-field inspection of single antennas.