Ground controlled precision landing delivery in the presence of radar disturbances

Abstract

Introduction: The purpose of Air Traffic Control is to ensure separation of aircraft in the most efficient manner possible. The need for efficiency is becoming more important as air traffic continues to increase at a high rate. Terminal area traffic control is the area in which the greatest amount of effort is expended since this tends to be the limiting factor in airspace congestion. The current Automated Radar Terminal System provides a monitoring function which was unheard of with previous systems. However, this is not sufficient in view of the increasing air traffic. More improvements are needed in the exchange of information between the ground controller and the aircraft. The proposed upgraded Air Traffic Control system will provide better data acquisition, communications service, and increased automation. Future systems should be capable of providing more complete automation in terms of command generation and delivery. These systems are called Strategic Navigation or Four-Dimensional Navigation. The principle of these systems is to assign a route-time profile to each aircraft thus providing good management of energy, space, and runways. This method utilizes a fixed airspace structure with a variable flight path to de-randomize aircraft runway arrival time. The method favored by the Federal Aviation Administration consists of ground computation of heading, altitude, and airspeed commands which are broadcast to the aircraft via digital data-link. These commands can be either visually displayed for manual operation by the pilot or at some future time directly tied into the aircraft auto-pilot. The purpose of this study is to simulate the flight of an aircraft on a terminal approach in a Four-Dimensional Navigation environment using discrete control commands. During the flight, position information is estimated from noisy radar observations. Speed is estimated from these observations and is used in a timed delivery algorithm to determine when to issue commands to the aircraft. Time control precision will be experimentally determined in the presence of the radar disturbance and accuracy of the Four-Dimensional Navigation task in the presence of this uncertainty will be quantified. A number of studies have previously been conducted to determine fix-to-fix and runway arrival time accuracy. These studies neglected the effect of wind and assumed perfect radar position information. For this reason a comprehensive model for these two effects was developed.