PRECISION AIRCRAFT HEIGHT ESTIMATION WITH HORIZONTAL-AXIS MARINE RADARS - (THE DUAL AUTONOMOUS MONITORING-SYSTEM (DAMS)

Civil aviation authorities have a requirement for the application of d evices which are capable of determining the geometric height of aircra ft above flight level 290 with a high degree of precision. These devic es, called height monitoring units (HMUS), should pave the way for a s afe and expeditious introduction of reduced vertical separation of 100 0 ft above flight level 290. In this paper the design philosophy as we ll as the prototype development of such a device, which is called the dual-synchronized autonomous monitoring system (DAMS), are outlined. T his device operates fully independently of any airborne equipment such as secondary surveillance radar transponders. The configuration basic ally consists of two standard marine radars with both axes of revoluti on situated in a horizontal plane. With this configuration it is possi ble to determine the trajectory of an aircraft and, in particular, the geometrical height above ground level within typical radar slant rang e coverage of some 18 km. The basic application of this equipment will be in the field of height monitoring of aircraft targets in environme nts with reduced vertical separation standards of 1000 ft above flight level 290, but a wider application of this concept is foreseen for lo cal precision tracking of aircraft targets.