| 摘要 |
Disclosed is a method and system that indicates the relative altitude of a vehicle. The method includes obtaining, from a navigation instrument, the current geographic position and altitude of the vehicle. Next, the geographic areas surrounding the current geographic position are defined. A minimum safe altitude (MSA) is determined for each geographic area based on a minimum clearance height and a maximum terrain elevation or a maximum obstruction elevation within the geographic areas. A relative altitude representing the current altitude of the vehicle relative to the MSA for each geographic area is determined. A relative altitude indicator is displayed via a presentation device for each geographic area based on the corresponding relative altitude. An indicator showing an MSA below the current altitude is graphically different to an indicator corresponding to an MSA above the current altitude. The system may assign a threat level to each area based on the relative altitude and the MSA. |
