抄録
This paper deals with the feasibility of the aircraft height monitoring systems composed of multiple SSR sensors. Two systems, one is a hybrid system using an SSR interrogator and SSR receivers and another is a passive system using only SSR receivers, are considered. The height estimation accuracy of these SSR-based systems are studied theoretically in terms of VDOP (Vertical Dilution of Precision). The distributions of calculated VDOPs for two systems composed of 4 sensors under the same geometrical configurations are examined and compared each other. The results show that the passive system has higher accuracy than the hybrid system has. Theoretical VDOP obtained for the passive system under the examined geometrical configurations becomes less than 1 when the target aircraft is in a close range from the reference SSR. This suggests that, under some limitted conditions, the absolute height measurement with the accuracy of 15m (1σ) or less may be possible using the proposed system.
