Height estimation of a cruising aircraft via a radar for air traffic control

Abstract

AbstractInformation on the three‐dimensional position of aircraft is necessary for air traffic control. The current height information of aircraft does not always show a geometric altitude since it is based on an onboard barometric altimetry system. Therefore, a method for monitoring the height of aircraft independently of barometric sensors is desirable.This paper describes a method of height estimation for an aircraft flying at a constant speed, level and straight using a radar for air traffic control currently in use or to be used in the near future, and presents the results of consideration on the estimation accuracy of the proposed method. In this method, the data taken by approximately ten times the scans by a fan beam are used for height estimation based on the curve which fits under the assumptions that the data acquisition area is nearly 10 NM the distance from the antenna.Height estimation accuracy by this method is evaluated by a computer simulation. The results show that height estimation accuracy depends strongly on the data acquisition area (that is, the geometrical relation between aircraft and the radar sensor), and the influence of range measurement accuracy is predominant at a cruising altitude of 29,000 ft (= 8.84 km). The height estimation accuracy is estimated to be approximately 100 m (1s̀) under the best conditions assuming that the standard deviation of range measurement errors is 30 m (1s̀) and that of azimuth errors is 0.06 deg (1s̀).